Download Learning Log/ FRQ-style Question

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The student is able to connect evolutionary changes in a population over time to a change in
the environment.
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LO 1.5 The student is able to connect evolutionary changes in a population over time to a
change in the environment.
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SP 7.1 The Student can connect phenomena and models across spatial and temporal scales.
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Evolution is effected by environmental changes such as climate, and habitat availability.
When a species evolves their phenotypes and genotypes may change which leads into the
gene and reproduction par tof biology.
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An mountain originally contained white, brown, and black ground dwelling birds. When a
volcano erupted the mountain was covered in black volcanic ash causing a shift to all black
birds. What kind of selection is this?
A. Disruptive selection
B. Stabilizing selection
C. Directional selection
D. Environmental selection
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When an earthquake occurred a species of birds had all of the trees they lived in knocked
down, describe how the birds would have evolved to survive.
Answer Key
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C directional selection is the correct answer.
When the population of birds lost their primary habitat they began to develop new methods.
The previously tree dwelling birds would have become ground dwelling. These birds would
developed new nesting methods to protect and hide their young while also finding new ways
to scavenge for food. This shows how environmental changes can effect evolution because
the habitat of these birds disappeared so the birds began to change.
Learning Objective 1.8
LO: The student is able to make predictions about the effects of genetic drift,
migration, and artificial selection on the genetic makeup of a population.
SP: The student can make claims and predictions about natural phenomena based on
scientific theories and models.
In order to master this objective, you need to be able to make predictions based off of provided
data, in addition to knowing the effects of genetic drift, migration, and artificial selection.
Genetic drift is the susceptibility of smaller populations to random, quick changes in allele
frequencies. For example, if a population of flowers had red and blue phenotypes, and the blue
flowers were more populous on a hill, and a rainstorm happened to wash them out. Migration is
the seasonal movement of a population from one area to another, like a flock of geese heading
south for the winter to avoid the cold. Artificial selection is the breeding of plants and animals to
MC
Question:
produce
desired traits, like genetically modified apples made to be bigger, redder, and sweeter.
Which of the following is an example of genetic drift?
A. A frog turning a darker shade of green to match the new breed of algae
growing in its ecosystem.
B. A population of fish containing two colors, red and blue, losing the
majority of its blue fish due to chance.
C. A population of bees choosing purple flowers over yellow flowers.
D. A dog wagging his tail due to his owner picking up his leash.
FRQ:
Compare and contrast natural selection
and artificial selection.
Example of genetic
drift:
Learning Objective 1.8 Answer Key (Answers highlighted in red)
MC Question:
Which of the following is an example of genetic drift?
A. A frog turning a darker shade of green to match the new breed of
algae growing in its ecosystem after many generations.
B. A population of fish containing two colors, red and blue, losing
the majority of its blue fish due to chance.
C. A population of bees choosing purple flowers over yellow flowers.
D. A dog wagging his tail due to his owner picking up his leash.
FRQ:
Compare and contrast natural
selection and artificial selection.
Natural selection is the outcome of environmental pressures acting
on a population. For example, if there were brown rabbits living in a
tundra, the brown rabbits would die out and adapt to a lighter shade
of fur. This would be because their darker fur stands out more
against the white snow, therefore making the brown rabbits more
susceptible to predators. Natural selection causes adaptations to
happen so that organisms may reproduce and thrive. Artificial
selection is man-mandated reproduction that is monitored and
controlled so that desired traits may be reproduced. This is evident
in dog breeding. Without dog breeding, purebred dogs would be
incredibly rare. In this case, the owners are purposefully making the
LO 3.42: The student is able to describe how organisms exchange information in response to internal changes or environmental cues
SP 7.1: The student can connect phenomena and models across spatial and temporal scales.
Explantation: Organisms exchange information with each other in response to internal changes and external cues, which can change behavior. The
internal response is produced, or motivated by the psyche or inner recesses of the mind, an example of the internal response is the nervous system.
The nervous interacts with sensory and internal body systems to coordinate responses and behaviors, ranging from movement, metabolism,
respiration, fight or flight response, and avoidance responses. The external cues are the detectable changes in the internal or external
environment, an example of external cues are the organisms ability to detect biological rhythms, mating behaviors, flowering, animal
communications and social structures.
Both internal response/changes and external/ environmental cues work mutually together, because the behavior of organisms is influenced by
internal cues (such as hunger) and by external cues (such as a change in the environment). This also means the amount of space (spatial) and time
(temporal) should work very close related to each other because loss of function and coordination within something like the nervous system
(internal response/changes) often results in severe changes in behavior (external/ environmental).
M.C Question: Which of the following is not an example of how responses to information and
communication are vital to natural selection innate and learned behaviors? Choose the best answer.
A) Parents leaving offspring to learn on their own
B) Migration patterns of butterflies
C) Courtship and mating behaviors in Birds
D) Avoidance behavior to electric fences, poisons, or traps
E) Foraging in bees and other animals
Learning Log/FRQ-style Question: While on a Safari in Africa you notice the once peaceful
antelopes start to stampede, What predictions can you make for their behavior? What internal and
external responses defines their reaction? What is a benefits to their behavior to gather in large
herds?
ANSWER KEY-LO 3.42
Which of the following is not an example of how responses to information and communication are vital to natural selection
innate and learned behaviors? Choose the best answer.
A) Parents leaving offspring to learn on their own
B) Migration patterns of butterflies
C) Courtship and mating behaviors in Birds
D) Avoidance behavior to electric fences, poisons, or traps
E) Foraging in bees and other animals
While on a Safari in Africa you notice the once peaceful antelopes start to stampede, What predictions can you make for their
behavior? What internal and external responses defines their reaction? What is a benefits to their behavior to gather in large
herds?
The reason for the antelopes(prey) behavior is because it probably felt threatened by a predator. The internal response
of the antelope was a avoidance response, which is a organism natural neurological response to retract away from
danger the external of that response is avoidance behavior. Another internal response was the flight or fight response
which is cause by the sympathetic nervous system, it prepares the body fight or flee, in the antelopes case, flee. The
external response was predator warning, which means something most have warned them danger was coming. The
benefit of the herding is that cooperative behavior tends to increase the fitness of the individual and the survival of the
population it's also beneficial because it ensure reproductive success. Stampeding can be a defense strategy for
antelopes since they depend on numbers and speed.
LO 2.12 The student is able to use representation and models to analyze situations or solve
problems qualitatively and quantitatively to investigate whether dynamic homeostasis is
maintained by the active movement of molecules across membranes.
SP 1.4 The student can describe representations of models to analyze situations or
solve problems qualitatively and quantitatively.
Explanation: In order to maintain dynamic homeostasis and growth cells utilize the
constant movement of molecules across cellular membrane. Passive transport does not
require the input of metabolic energy. The net movement of molecules is from high
concentration to low concentration. Be able to analyze U-tubes and solve math
questions based on molarity and water potential.
Multiple Choice Question: In the diagram below, which side would the water move to maintain homeostasis?
A. Side A to Side B
B. Side B to Side A
C. Side A is equal to Side B
D. Not enough information given
FRQ: By using the diagram describe what is happening in
side A(0.4M) and side B(0.6M) of the U-tube. If side A
contained 0.6M of NaCl solution and created a solute
potential of -0.33MP and a pressure potential of +0.14. Side
B contains distilled water with a pressure potential of -0.20.
Calculate the water potential for side A and side B. Then
describe what would happen via osmosis.
Multiple Choice Question: In the diagram below, which side would the water
move to maintain homeostasis?
A. Side A to Side B
B. Side B to Side A
C. Side A is equal to Side B
D. Not enough information given
FRQ: By using the diagram describe what is happening in side A(0.4M) and side
B(0.6M) of the U-tube. If side A contained 0.6M of NaCl solution and created a solute
potential of -0.33MP and a pressure potential of +0.14. Side B contains distilled water
with a pressure potential of -0.20. Calculate the water potential for side A and side B.
Then describe what would happen via osmosis.
Side A contains solutes which makes the molarity of
water to be higher than side B, therefore, as water
flows from high concentration of water to low
concentration, water from side A will flow into side B
to maintain homeostasis.
Water potential A=-0.19MP
Water potential B= -0.20MP
Water will move from side A to side B via osmosis.
LO 4.14 The student is able to apply mathematical routines to quantities that describe interactions among
living systems and their environment, which result in the movement of matter and energy.
SP 2.2 The student can apply mathematical routines to quantities that describe natural phenomena.
Explanation: Matter and energy are recycled but never destroyed. In a food chain there is less energy at the top
because 90% of energy at each level is released as heat. Only 10% is useable energy as it moves up a level.
Because of this it takes a larger amount of producers to support a consumer. Amount of light energy converted to
chemical energy by autotrophs is measured as Gross Primary Productivity or Net Primary Productivity. NPP is the
GPP minus the respiration or energy used by organisms. As organisms are born or die the amount of matter in an
area changes. This population can either grow logistically or exponentially, and the growth rate is measured by the
change in population size divided by the change in time. Exponential growth begins slowly and then the rate
increases, without concern for resources. Logistic growth begins rapidly but slows as the carrying capacity, or
maximum amount of usable resources, is approached.
MC Question: Clemmons, North Carolina has a population of 20,000 in 2014. The infrastructure of the city allows
for a carrying capacity of 45,000 people and r-max=.85. What will the population growth rate by for 2014?
A. 8506 people/year
B. 9444 people/year
C. 15000 people/year
D. 17000 people/year
Learning Log/FRQ Style Question:
A) In a desert environment the primary producer cactus
contains 5287kcal of energy. How much of that energy
reaches the tertiary consumer in the desert food chain? How much energy is
released and as what?
B) If another secondary consumer would introduced into the environment,
how would this affect the population of ants?
Answer Key- LO 4.14
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MC Question: Clemmons, North Carolina has a population of 20,000 in 2014. The
infrastructure of the city allows for a carrying capacity of 45,000 people and rmax=.85. What will the population growth rate by for 2014?
A. 8506 people/year
B. 9444 people/year
C. 15000 people/year
D. 17000 people/year
(.85)(20000)[(45000-20000)/45000] = 9444
Learning Log/FRQ Style Question:
A) In a desert environment the primary producer cactus contains 5287kcal of energy.
How much of that energy reaches the tertiary consumer in the desert food chain? How
much energy is released and as what?
(5287)(.1)(.1)(.1)= 5.287kcal
5287-5.287= 5281.713kcal is released as heat
B) If another secondary consumer would introduced into the environment,
how would this affect the population of ants?
The increased amount of energy needed to support the secondary consumer level
would lead to an increase in the amount of ants consumed. This decreases the ant
population.
LO 4.24: The Student is able to predict the effects of a change in an environmental factor
on the genotypic expression of the phenotype.
SP 6.4: The student can make claims and predictions about natural phenomena based on
scientific theories and models.
Explanation: An organism's ability to adapt to a changing environment is essential in its
survival. As the environment changes, due to something like season, organisms in that
environment change to fit the new environment. This is different than natural selection
because it happens during an organisms lifetime and not over generations. For example, as
the season in the artic shifts to winter, many animals develop lighter fur color than during
the summer months. The environment leads to a change in gene expression, leading to a
change in phenotype, in a particular organism.
M.C. Question: Which of the following situations is the best example of a genetic change
leading to a change in phenotype?
A) Black mice becoming more suitable to survive in a darker environment than brown mice.
B) A flood wiping out plants that have a shorter phenotype, leaving only tall plants
C) A leaf changing color due to light/ temperature change throughout the year
D) Squirrels that run faster have a higher chance of survival than those who run slower
FRQ-Style question: Describe an environmental factor that would cause a change in gene
expression, and the affect that it would have on the phenotype of an organism.
This diagram shows how a gene is
expressed through the process of
transcription and translation. A change
in gene will lead to a different protein
being transcribed and a different
phenotype being expressed.
Answer Key- LO 4.24
Which of the following situations is the best example of a genetic change leading to a
change in phenotype?
A) Black mice becoming more suitable to survive in a darker environment than brown
mice.
B) A flood wiping out flowers that have a shorter phenotype
C) A leaf changing color due to light/ temperature changes throughout the year
D) Squirrels that run faster have a higher chance of survival than those who run slower
Describe an environmental factor that would cause a change in gene expression, and
the affect that it would have on an organism.
Many bacteria respond to an environment with and without the presence of lactose.
If lactose is present in the environment, a genetic operon repressor is inactive, and a
gene is transcribed to produce enzymes for lactose utilization. If lactose is not
present, the repressor is active and blocks the transcription of enzymes for lactose
utilization. This shows how a change in the environment can lead to a change in gene
expression, causing a change in the phenotype of an organism.
(Amy example that shows the genetic change that the environment has on a
particular organism, not an entire population, could be acceptable.)
LO 2.7 Students will be able to explain how cell size and shape affect the overall rate of nutrient intake and the rate of waste elimination.
SP 6.2 The student can construct explanations of phenomena
based on evidence produced through scientific practices.
Explanation: Biological organisms must obtain resources and excrete waste to survive. Surface area to volume ratios greatly affect these
capabilities. Consider a plant’s root cell of a plant that is of ideal size and is
capable of appropriately absorbing necessities and excreting waste. If the root cell
grows outwards from the center, then its volume has increased. Because the cell is
larger, it now requires more resources, like water and nutrients. To allow for the
increased cotransport (process of using the effects of the H+ gradient to couple
downhill passage of H+ with uphill passage of another solute into the cell) of such
resources, the cell needs more cellular “equipment” (like proton pumps which facilitate
cotransport). To make room for this “equipment,” the cell needs more surface area for
the “equipment” to exist. This extra space could be created with root extensions, as
shown to the right.
M.C. Question:
Which process is not heavily reliant on a close surface area to volume ratio?
A. discharge of broken macromolecules after digestion and recycling by lysosomes
B. achievement of an action potential by a neuron
C. independent assortment during metaphase I
D. absorption of CO2 and expulsion of O2 via stomata in plants
Learning Log/FRQ-Style Question:
Identify and describe two structures that can increase a cell’s surface area without significantly, if at all, increasing volume. How can the addition
of these structures benefit an organism?
ANSWER KEY - LO 2.7
M.C. Question:
Which process is not heavily reliant on a close surface area to volume ratio?
A. discharge of broken macromolecules after digestion and recycling by lysosomes
B. achievement of an action potential by a neuron
C. independent assortment during metaphase I
D. absorption of CO2 and expulsion of O2 via stomata in plants
Learning Log/FRQ-Style Question:
Identify and describe two structures that can increase a cell’s surface area without significantly, if at all, increasing volume. How can the addition
of these structures benefit an organism?
Root hairs, cells of the alveoli, and cells of the villi are all examples of structures that can increase a cell’s surface area without significantly, if
at all, increasing volume. Root hairs are cylindrical extensions of the epidermis. Root hairs on plant roots can increase surface area to
maximize the absorption of water and nutrients from the soil. The alveoli exist in the lungs and are small air pockets where the
exchange of CO2 and O2 take place. The development of more alveoli would allow for a more efficient exchange of CO2 and O2. Villi are
small vascular extensions and can be found in the intestine. An increase in surface area via villi would speed up the process of waste
filtration before excretion.
LO 4.23 - The student is able to construct explanations of the influence of environmental factors on the phenotype of an organism.
SP 6.2 - The student can construct explanations of phenomena based on evidence produced through scientific practices.
Explanation: The phenotype of an organism is greatly influenced by its environment. Examples of this would be when a Arctic fox’s fur turns
from white to brown in the summer due to heat sensitive alleles. Or how the color of Hydrangea flowers is related to the PH of the surrounding
soil. These environmental factors affect the phenotype of the organism to a certain extent while the genotype is the main determinant. This can
be seen in humans skin and hair color as the environment such as the sun causes lightening or darkening of skin and hair. The degree to which
your phenotype is determined by your genotype is referred to as ‘phenotypic plasticity’. If environmental factors have a strong influence, the
phenotypic plasticity is high. If genotype can be used to reliably predict phenotype, the phenotypic plasticity is low.
MC Question: Which of the following is an example of environmental influences on phenotypes in humans?
A. Eye Color
B. Weight
C. Height
D. Both B and C
Learning Log/ FRQ-style Question:
How might environmental factors affect height and weight in humans?
How might environmental factors be changed to benefit humans?
Provide at least one other example of environmental influence on
an organism.
MC Question: Which of the following is an example of environmental influences on phenotypes in humans?
A. Eye Color
B. Weight
C. Height
D. Both B and C
How might environmental factors affect height and weight in humans?
How might environmental factors be changed to benefit humans?
Provide at least one other example of environmental influence on
an organism.
Height and weight are influenced by diet and exercise along side your genetic make up. Changes in the environment include reducing stress
or controlling the quantity and quality of food intake. Along with ensuring an adequate amount of exercise is being met. Another example of
the influence of the environment on phenotype is the Arctic Fox. The Arctic Fox’s white fur allows for it to blend in with its surroundings
however during the warmer months is fur turns a brownish black by the activation of heat sensitive alleles allowing it to still blend with its
environment.
LO 3.18: The student is able to describe the connection between the regulation of gene
expression and observed differences in different kinds of organisms.
SP 7.1: The students can connect phenomena and models across spatial and temporal scales.
Explanation: Gene regulation is the process where genes are turned on and off and in doing so, cells begin to take on specific
functions during early development. Chemical signals and regulatory proteins are used to regulate genes. Gene regulation verifies
the fact that appropriate genes are expressed at the proper times. There's an abundance of organisms that have familiar genes,
being that all organisms share a common ancestor. Transcription, RNA splicing and Translation are all steps that are present within
the regulation of genes. Cells are given instructions for their structure and function all due to gene regulation, and it is the basis for
cellular differentiation and morphogenesis . When certain genes within an organism are expressed, the expression gives rise and
controls the organisms phenotype. Certain transcription factors like activators, RNA polymerase, and repressors regulate whether
or not a protein is made. Promoters bind to a specific gene, RNA polymerase reads and copies the DNA turning it into RNA, and
that RNA undergoes translation where proteins are then made. 80% of the genes present in humans are the exact same as those
present in Zebra Fish, proving that it is possible to share genes with something of completely opposite species. The genes that we
share with the Zebra Fish are both used for growth and development, but; differences in the proteins produced in translation effect
the difference in the appearance and function of the Zebra Fish and humans.
M.C. Question :
Gene expression regulation is a key process in the survival of organisms all
around. If gene expression regulation was not properly functioning, which of
the following could not be a result?
A) Cancer
B) No RNA synthesis
C) Over production of Promoter genes
D) Lack of necessary protein production
Learn Log/ FRQ- style Question: Gene regulation expression is
composed of several stages, all
serving a different function. (a) List three of
the stages involved in this process and (b) thoroughly
explain two of the three processes that you list .
Answer Key- LO
3.18
Gene expression regulation is a key process in the survival of organisms all
around. If gene expression regulation was not properly functioning, which of
the following could not be a result?
A) Cancer
B) No RNA synthesis
C) Over production of Promoter genes
D) Lack of necessary protein production
Gene regulation expression is composed of several stages, all
serving a different function. (a) List three of
the stages involved in this process and (b) thoroughly
explain two of the three processes that you list.
Transcription, translation, and RNA splicing are three stages of gene regulation expression.
Transcription is the first step in gene expression, where DNA is translated into RNA via the
help of RNA polymerase. RNA polymerase creates a transcription bubble that separates the
DNA helix, which is done by breaking hydrogen bonds between the DNA nucleotides. RNA polymerase
adds complementary nucleotides to the template strand, and nucleotides are added to the 3 prime end of
the RNA molecule. Hydrogen bonds are broken from the RNA-DNA
helix, letting the new RNA strand free. A cap and tail are added to the ends of the new RNA molecule
for protection when leaving the nucleus. Translation is the process where mRNA is sequenced to
later create proteins. Translation begins by a small subunit binding to a specific sequence on the
mRNA. This newly formed initiating codon is later bound by the tRNA molecule which transfers
an amino acid to the tRNA corresponding to the next codon. The ribosome then continues to the
next mRNA codon to continue making amino acids. Stop codons come in at a certain point to release
the polypeptide and stop the process.
LO 3.27: The student is able to compare and contrast processes by which genetic variation is
produced and maintained in organisms from multiple domains.
SP 7.2: The student can connect concepts in and across domain(s) to generalize or extrapolate in Genetic Variation in
Humans
and/or across enduring understandings and/or big ideas.
Explanation: Genetic variation occurs when genetic information is changed. Genetic information can
be changed through two main processes, mutations and sexual reproduction. Random mutations are
the ultimate source of genetic variation in an organism. For example, mutations can occur in the
process of DNA replication, which if left unrepaired (DNA repair process), can become permanent
mutations and can be passed on to the next generation, leading to genetic variation. In meiotic
organisms, sexual reproduction helps to achieve generic variation. The transfer process of meiosis, in
which each gamete receives ones set of chromosomes, ensures that each set is unique and different
from the parents, through the method of crossing over. Crossing over is the exchange of genetic
material between homologous chromosomes that results in recombinant chromosomes. In crossing
over, DNA from two parents is combined into a single chromosome, creating a entirely new and
unique chromosome, thus increasing genetic variation. Maintaining genetic variation is essential to
organisms living in a dynamic environment. Natural selection is the primary way genetic variation is
maintained. For example, in heterozygous individuals, potentially harmful recessive alleles can be
hidden from selection in populations of diploid organisms, thus creating a change in genetic
information and leading to genetic variation.
M.C. Question: Single nucleotide polymorphisms, frequently called SNPs (pronounced “snips”), are
the most common type of genetic variation among people. How do SNP’s cause increases in genetic
variation?
A) The SNP changes the properties of the DNA, thus creating variation.
B) The SNP deletes a single nucleotide which changes the sequence, thus creating genetic variation.
C) The SNP changes a single nucleotide in the DNA sequence, which produces a variation that
can be followed over time and quantified.
D) The SNP adds multiple nucleotides to the DNA sequence, thus creating variation.
Learning Log/ FRQ-style Question: How can the processes of DNA replication and repair increase
Mutation
Causing Genetic
Variation
ANSWER KEY- LO 3.27
Single nucleotide polymorphisms, frequently called SNPs (pronounced “snips”), are the most common
type of genetic variation among people. How do SNP’s cause increases in genetic variation?
A) The SNP changes the properties of the DNA, thus creating variation.
B) The SNP deletes a single nucleotide which changes the sequence, thus creating genetic variation.
C) The SNP changes a single nucleotide in the DNA sequence, which produces a variation that can be
followed over time and quantified.
D) The SNP adds multiple nucleotides to the DNA sequence, thus creating variation.
How can the processes of DNA replication and repair increase genetic variation? Explain.
The processes of DNA replication and repair are imperfect, meaning they can lead to random
mutations. During DNA replication, polymerase enzymes sometimes insert the wrong nucleotide, or
too many or too few nucleotides into the sequence. Most of the time, these mistakes are fixed during
the DNA repair process in which repair enzymes recognize structural imperfections, cut out the
wrong ones and put the right ones in their place. If these mistakes go unrepaired during the DNA
repair process, they can become permanent mutations, which are then passed on to the next
generation, thus increasing genetic variation.
LO 3.45: The student is able to describe how nervous systems transmit information.
SP 1.2: The student can describe representations and models of natural or man-made phenomena and
systems in the domain.
Explanation: Nervous systems transmit information via neurons. To create an action potential, sodium
channels are opened because as Na+ ions enter the neuron, it becomes less negative and approaches the
threshold at -55 mV; potassium channels remain closed because if K+ ions leave the neuron, it becomes
more negative. The action potential moves away from the cell and down the axon. When the action
potential reaches the end of the pre-synaptic cell, the voltage gated Ca2+ channels open to allow Ca2+ to
diffuse down its concentration gradient, allowing vesicles holding the neurotransmitter to diffuse with the
pre-synaptic membrane. The neurotransmitter is then deposited into the synapse where it will then binds to
the post-synaptic cell. The neurotransmitter acts as a ligand and binds to a ligand-gated ion channel that
either depolarizes or hyperpolarizes the cell depending on which channel it binds to; once the
neurotransmitter is removed, the ligand-gated ion channel closes.
M.C. Question: Which of the following statements about neurons is true?
A) The action potential travels down the dendrites; the axons receive
the signal.
B) Neurons contain no organelles unlike other living cells of the
body.
C) Neurons have a negative charge due to proteins and genetic
material within the cell.
D) None of the above.
Learning Log/FRQ-style Question: Suppose a neuron’s membrane
allows Na+ ions to freely flow in and out of the cell. Describe how
this may or may not effect transmission of information, and why.
ANSWER KEY – LO 4.1
Which of the following statements about neurons is true?
A) The action potential travels down the dendrites; the axons receive the signal.
B) Neurons contain no organelles unlike other living cells of the body.
C) Neurons have a negative charge due to proteins and genetic material within the cell.
D) None of the above.
Suppose a neuron’s membrane allows Na+ ions to freely flow in and out of the cell. Describe how this
may or may not effect transmission of information, and why.
In a normal neuron cell, though some Na+ ions are
able to diffuse into the membrane, most cannot. If
the membrane allowed these ions to freely flow in
and out of the cell, more Na+ ions would enter the
cell, moving from a high concentration to a low
concentration, causing the charge within the cell to
be more positive. Maintaining the resting charge of
the neuron would be very hard. It’s likely action
potentials would be fired even when unnecessary
because the new resting charge is less negative so
it’s more easy to reach or exceed the threshold,
sending signals that are not needed.
LO 3.13- The student is able to pose questions about ethical, social or medical issues
surrounding human genetic disorders
SP-3.1 The student can pose scientific questions.
Explanation: A vast majority of genetic disorders are very difficult to cure as they are caused by mutations in
genes; they also are commonly inherited disorders. These disorders can cause ethical and social issues as some
individuals with them don’t have children for fear of passing on these genetic disorders to their offspring. People
that do suffer from genetic disorders may be impaired physically and/or mentally and could have a hard time
functioning in society without special help. Furthermore, some jobs may discriminate against employees if they
find out the employee has a genetic disorder due to insurance policies. For example, a large debate surrounding
projects like the Human Genome Project centers around whether corporations should be able to access people’s
genetic information. This is due to potential privacy violations and also the potential of corporations to abuse the
information and discriminate against workers with genetic disorders. Other issues may include the safety of
certain gene therapies and the controversies surrounding stem cell research (embryonic stem cells in particular).
MC Question: What is a potential downside to a genetic test?
a) The individual might already be too late to prevent the symptoms of the disorder
b) Genetic tests are not regulated by the US government and have health risks
c)
Some genetic disorders have no cure even if discovered
d) Genetic tests are expensive and have disputed validity
FRQ Question: Mr. Frank, a 37 year old corporate salesperson who is healthy and fit, suddenly starts to suffer from
depression and mood swings. A few months later, Mr. Frank begins to have difficulty speaking and keeping his
balance. His doctor advised Mr. Frank to see a genetic counselor, after discussing the results of the genetic
tests with his counselor and recalling that his father had similar symptoms when he was younger, Mr. Frank
begins to worry about his 2 children. What disorder does Mr. Frank likely have and how could it affect his life
and family? Explain.
Answer Key-LO 3.13
•
a)
b)
c)
d)
MC Question: What is a potential downside to a genetic test?
The individual might already be too late to prevent the symptoms of the disorder
Genetic tests are not regulated by the US government and have health risks
Some genetic disorders have no cure even if discovered
Genetic tests are expensive and have disputed validity
Mr. Frank, a 37 year old man who is healthy and fit, suddenly starts to suffer from depression and mood
swings. A few months later, Mr. Frank begins to have difficulty speaking and keeping his balance. His doctor advised
Mr. Frank to see a genetic counselor, after discussing the results of the genetic tests with his counselor and
recalling that his father had similar symptoms when he was younger, Mr. Frank begins to worry about his 2
children. What disorder does Mr. Frank likely have and how could it affect his life? Explain .
Mr. Frank likely suffers from Huntington’s disease, an autosomal dominant disorder that most
commonly begins to exhibit symptoms around the ages of 35 and 44 and will cause a progressive
deterioration of motor movement and of cognitive function. Huntington’s disease generally will
not skip a generation unless the individual(s) afflicted has the early onset form and passes away
before having children. Mr. Frank will likely need therapy, treatment, and certain drugs to treat
the symptoms of Huntington’s( an increased financial strain). Mr. Frank also will need to resolve
the implications of the profound results with his employers and his insurance company. Finally,
there is a 50% chance either of Mr. Frank’s children have the disease.
LO 3.3: The student is able to describe representations and models that illustrate how genetic
information is copied for transmission between generations.
SP 1.2: The student can describe representations and models of natural or man-made phenomena
and systems in the domain.
Explanation: Along with the transfer of genetic information from cell- to- cell, information also
transferred between generations. This process of transmission can be identified with proper
understanding of 3 important sub-processes: replication, transcription, and translation.
Replication is the creation of an identical strand of DNA in order for inheritance to occur. The
strand then undergoes transcription in to messenger RNA (mRNA). This mRNA is important for
directing translation into proteins allowing for transmission between generations. Representations
of the transmission of genetic information between generation include punnett squares,
karyotypes, and family trees. Punnett squares are used to identify possible inherited genes to
offspring from parents. Family trees keep track of genetic variation between generations, and is
often helpful in the recording of genetic diseases.
M.C. Question: The ability to roll your tongue is a dominant trait. The inability to roll your tongue is
a recessive trait. If two people are homozygous recessive, what is the probability that their first
child will have this trait?
A. 75%
B. 25%
C. 50%
D. 0%
Learning Log/FRQ-style Question: Describe a Punnett square and how it is used.
ANSWER KEY – L.O. 3.3
M.C. Question: The ability to roll your tongue is a dominant trait. The inability to roll your tongue is
a recessive trait. If two people are homozygous recessive, what is the probability that their first
child will have this trait?
A. 75%
B. 25%
C. 50%
D. 0%
Learning Log/ FRQ: Describe a test cross and how it is used.
Possible Answer: Punnett squares are methods for determining possible genetic outcomes of
offspring. It can provide the probability of inheritance of specific genes. In order, for it to work
genotypes of both parents must be available.
Possible Drawing:
In this case, both
A
a
parents are
heterozygous for
the trait. There is a
25% possibility of
A
being homozygous
dominant. 50%
possibility of being
heterozygous and
25% possibility of
a
being homozygous
recessive.
AA
Aa
Aa
aa
LO 3.26: The student is able to explain the connection between genetic variations in organisms
and phenotypic variations in populations.
SP 7.2: The student can connect concepts in and across domain(s) to generalize or extrapolate
in and/or across enduring understandings and/or big ideas.
•
This learning objective is about how the various genotypes of a population determine the various phenotypes of that
population. For example, if a population contained 25 individuals with the homozygous recessive genotype, 25
individuals with the homozygous dominant genotype, and 50 individuals with the heterozygous genotype, and normal
rules of dominance were in place, then three fourths of the population would display the dominant phenotype and one
fourth would display the recessive phenotype. Genetic variations would change the genotypes found in the population,
and thus would also change the phenotypes. Genetic variation can result from mutations or problems during
reproduction, such as nondisjunction, and can also result from new individuals coming into a population or
parts of the population becoming reproductively isolated from each other. For example, if there was a
population made up entirely of green toads on an island but a few brown toads came in on a boat and
reproduced with the green toads, the genetic variation of that population would increase and there
would be a variety of different color phenotypes instead of just the original green.
•
A population of rats lives on a volcanic island. One side of the island is mostly flat and shrubby while
the other side is steep and rocky. In the middle of the island is a volcano. The volcano erupts and
Isolates the rats on one side of the island from those on the other. Fifty years later, the populations become
spectiated. What is the best explanation for this speciation?
a)
The members of each population develop vastly different behaviors in order to survive.
b)
Because the populations are geographically isolated, they accumulate different adaptations.
c)
The rats in the less favorable habitat die out while those in the more favorable survive.
d)
New species will come in on boats and only be exposed to one population of the rats.
In a population of cats, the dominant allele H codes for long hair and the recessive allele h codes for short hair. Cats
with the heterozygous genotype have medium length hair.
a)
If the genotype of the population has an equal number of H alleles as it does of h alleles, what percent of the
population displays each of the three phenotypes? How do you know this?
•
Answer Key: LO 3.26
•
•
A population of rats lives on a volcanic island. One side of the island is mostly flat and shrubby while the other side is steep and rocky. In the
middle of the island is a volcano. The volcano erupts and isolates the rats on one side of the island from those on the other. Fifty years later, the
populations become spectiated. What is the best explanation for this speciation?
a)
The members of each population develop vastly different behaviors in order to survive.
b)
Because the populations are geographically isolated, they accumulate different adaptations.
c)
The rats in the less favorable habitat die out while those in the more favorable survive.
d)
New species will come in on boats and only be exposed to one population of the rats.
In a population of cats, the dominant allele H codes for long hair and the recessive allele h codes for short hair. Cats with the heterozygous
genotype have medium length hair.
a)
If the genotype of the population has an equal number of H alleles as it does of h alleles and 25% of the population has short hair, what
percent of the population displays each of the remaining two genotypes? How do you know this?
b)
As years pass, the number of cats with short hair within the population drastically decreases. Described three possible explanations for
why this could occur.
a.
q squared=.25
q=.5
p+q=1
p+.5=1
p=.5
p squared=.25
So:
25% of the population is homozygous dominant
50% of the population is heterozygous
b.
The cats could live in a cold place, so natural selection would favor those with long hair, which is coded for with the H allele. Those with longer
hair would be able to survive and successfully reproduce more often than those with short hair or medium length hair, which would lead to
natural selection favoring the H allele. There would be a higher frequency of the H allele, a lower frequency of the h allele, and thus a smaller
number of cats with short hair.
A mutation could occur in the h allele that would cause a harmful effect. This would prevent cats with the h allele from being able to survive
and reproduce nearly as often, which would lead to natural selection against those with the harmful allele. This would cause the frequency of
the h allele to decrease and a smaller number of cats in the population to have short hair.
A drastic event, such as a drought or fire, could occur within the habitat of the population and kill off most of it. Due to the bottleneck effect,
of a population over time.
SP 5.3: The student can evaluate the evidence provided by data sets in relation to a particular scientific question.
Explanation: Evolutionary changes happen if one genotype within a population is more successful than another.
Because the individuals with this more successful genotype are more fit for their environment, they will have a higher
survival rate and therefore a higher reproductive rate, meaning that over the next few generations there will be an
increase in the number of individuals with that genotype. Evidence for evolutionary change can come from the
increased or decreased abundance of a certain phenotype Evolutionary changes in genetic makeup of a population
over time are typically measured by allelic frequencies. The Hardy-Weinberg equations, p+q=1 and p^2+2pq+q^2=1,
are used to determine these frequencies in populations that follow the five conditions of Hardy-Weinberg equilibrium.
These conditions are: large breeding population, random mating, no mutations, no migration, and no selection.
Learning Log Style Question:
In Africa, malaria is very common disease, spread by mosquitos. However, individuals who have a
genotype of Aa for sickle cell anemia do not get infected with malaria.
a)
Explain why these individuals do not get malaria. (CUES: heterozygote advantage)
b)
Predict what will happen to the frequency of heterozygotes in this population over the next
couple hundred years.
c)
Using the Hardy-Weinberg equations, p+q=1 and p^2+2pq+q^2=1, solve the following
problem. If 4 percent of the population of a tribe in Africa have the recessive trait for sickle cell
anemia, and 100 babies were born in the new year, approximately how many of the babies
would you expect for each of the three possible genotypes? What five conditions must be
assumed in order for this data to be accepted?
Multiple choice:
From the early 1800s when the species was first introduced up until 1910, approximately ten percent
of the population of mice were homozygous recessive, showing a phenotype of dark hair. In 1960,
thirty percent of the same population were homozygous recessive. In 2012 ninety percent of the
mouse population was homozygous recessive. Which of the following best explains the reason for this
pattern?
A) Female mice are only attracted the male mice with darker hair, therefor the frequency of dark
colored mice increased
B) A change occurred in the environment that caused the recessive phenotype to be more favorable,
therefore the frequency of homozygous recessive organisms increased
C) The same amount of dark and light colored mice are born each year up to 2012, but only the dark
colored ones survive long
D) The two colored mice evolved into two different species of mice, and now there is one species of
dark colored mice and another species of light colored mice.
Example of Hardy-Weinberg
approach to determining
Answer Key LO 1.4
•
Multiple choice: B.
–
–
–
–
Answer choice A is not correct because we are told that for the first 110 years there was a very high
percentage of light colored mice, meaning that females are in fact attracted to them.
Answer choice B is correct because this accounts for the long initial period of little to no evolution,
followed by a rapid evolutionary change.
Answer choice C is not correct because if the light colored mice die early, they will not live long enough
to reproduce therefore the population of light colored mice will decrease. Also, we are told that 90% of
the population is dark colored, so less than half are born light colored.
Answer choice D is not correct because in the problem we are told that the population still has 10%
white mice, meaning they have not become two species.
Learning Log Question:
Individuals with type Aa genotype are considered to have a heterozygote advantage. Heterozygous
individuals cannot get malaria, and for this reason the frequency of heterozygotes in this population will
increase in the next couple hundred years because these individuals are more fit for their environment.
Part C: AA=72
Aa=96
Aa=32
The five conditions for the data collected from the Hardy-Weinberg equations are:
1.
The breeding population is large.
2.
Mating is random.
3.
There is no mutation of the alleles.
4.
No differential migration occurs(immigration and emigration)
5.
There is no selection.
LO 4.4: The student is able to make a prediction about the interactions of subcellular organelles.
SP 6.4:The student can make claims and predictions about natural phenomena based on
scientific theories and models.
Explanation: Ribosomes are small structures comprised of two interacting parts: ribosomal RNA and protein.
These cellular components interact to become the site of protein synthesis where the translation of the
genetic instructions yields specific polypeptides. Rough endoplasmic reticulum functions to compartmentalize
the cell, serves as mechanical support, provides site-specific protein synthesis with membrane-bound
ribosomes and plays a role in intracellular transport. The smooth ER synthesizes lipids. The Golgi Apparatus
synthesizes and packages materials for transport and produces lysosomes. Mitochondria have a double
membrane that allows compartmentalization within the mitochondria and is important to its function. The
outer membrane is smooth, but the inner membrane is highly convoluted, forming folds called cristae. Cristae
contain enzymes important to ATP production; cristae also increase the surface area for ATP production.
Lysosomes are membrane-enclosed sacs that contain hydrolytic enzymes, which are important in intracellular
digestion, the recycling of a cell’s organic materials and programmed cell death (apoptosis). Lysosomes carry
out intracellular digestion in a variety of ways. A vacuole is a membrane-bound sac that plays roles in
intracellular digestion and the release of cellular waste products.
M.C. Question: Which of the following is not modified/processed by the Golgi Apparatus?
A) sugars of glycoproteins
B) membrane phospholipids
C) hormones to be secreted
D) DNA/RNA
Learning Log/FRQ-style Question: Suppose that the lysosomes of a cell were damaged and rendered unable to
function. How would this affect homeostasis? Describe one condition or disease related to lysosome function.
Answer Key- LO 4.4
Which of the following is not
modified/processed by the Golgi
Apparatus?
A) sugars of glycoproteins
B) membrane phospholipids
C) hormones to be secreted
D) DNA/RNA
Suppose that the lysosomes of a cell were damaged and rendered unable to function. How would
this affect homeostasis? Describe one condition or disease related to lysosome function.
Lysosomes assist in intercellular digestion. If lysosomes were damaged and rendered unable to
function, then the cell wouldn’t be able to digest or break down molecules. The cell would lack
energy from food digestion and waste buildup would occur. One disease that is related to
lysosomes is Tay-Sachs Disease. In this disease, wastes (specifically fatty acids) build up in the
cell and cause neurological damage. Tay-Sachs Disease is typically affects the nervous tissue of
the brain and spinal chord.
LO 3.48 : The student is able to create a visual representation to describe how nervous
systems detect external and internal signals
SP 1.1: The student can create representations and models of natural or man-made
phenomena and systems in the domain.
Explanation: The sensory neurons, located in the central nervous system, detects the
stimulus which are the external and internal signals. The stimulus travels through the
sensory neurons as nerve impulses. They then turn into neurotransmitters, a chemical form,
when in the synapse. The synapse is the space between the neurons. The CNS creates
sensory input which can informally be defined as a message that will be sent to the motor
neurons. The message travels through the interneurons to the motor neurons which are
located in the peripheral nervous system. The motor neurons create a motor output which
can cause body movement, gland secretion, and other reactions throughout the body.
M.C. Question: The CNS and PNS are both responsible for the body’s reaction to
environmental and internal stimulus. However the two systems have different functions in the
process. Which of the following is true concerning the PNS?
I. The PNS consists of the motor neurons, sensory neurons, and interneurons.
II. The PNS can be responsible for activating the endocrine system.
III. The PNS is the primary system associated with the fight or flight response.
(A) I only
(B) II only
(C) I and III
(D) II and III
(E) I, II, and III
Learning Log/ FRQ-style Question: Suppose you were walking down
the street and you saw your favorite band in the entire world
on a casual stroll. Which part of the autonomic nervous system
would most likely become activated once you see the band? List
at least three symptoms that you will start to experience once
you see the band? After you have met the band and continue
walking down the street, which nervous system will become active?
Why?
Answer Key – LO 3.48
The CNS and PNS are both responsible for the body’s reaction to environmental and internal stimulus. However the
two systems have different functions in the process. Which of the following is true concerning the PNS?
I. The PNS consist of the motor neurons, sensory neurons, and interneurons.
II. The PNS can be responsible for activating the endocrine system.
III. The PNS is the primary system associated with the fight or flight response.
(A) I only
(B) II only
(C) I and III
(D) II and III
(E) I, II, and III
Suppose you were on an ordinary walk in the park and you saw your favorite band in the entire world on a casual stroll.
Which part of the autonomic nervous system would most likely become activated once you see the band? What
symptoms will you start to experience once you see the band? After you have met the band and continue walking down
the street, which nervous system will become active? Why?
If I saw my favorite band while walking down the street my sympathetic nervous system would most likely
become activated due to excitement. Once the sympathetic nervous system becomes activated my bladder will
become relaxed, my heart rate will increase, and my pupils will dilate (Any three symptoms of the sympathetic
nervous system will be accurate). Once the band continues on their stroll the parasympathetic system will
become activated. The parasympathetic nervous system will become activated so that my body will return to a
normal and calm state. The parasympathetic nervous system will become activated to preserve energy in an
ordinary scenario such as walking in the park ( Many of the functions of the parasympathetic nervous system
will be responsible for answering why).
LO 3.28:The student is able to construct an explanation of the multiple processes that increase variation within a
population.
SP 6.2: The student can construct explanations of phenomena based on evidence produced through scientific processes.
Explanation: In a population, various processes increase the variation and which is more beneficial to a population
as a whole. Genetic variation increases a populations chance of survival because there are more genes or options in
the gene pool to be selected for or against. Mutations are a large contributor to genetic variation because they are
random switches of DNA. Several mutations include insertions and deletions, both of which can lead to different
amino acid sequences, leading to construction of different proteins. Crossing over is also a random process that
creates variation. In prophase I, nonsister chromatids exchange genetic material causing a mixing of DNA. Variation
is also created by the independent assortment of alleles on nonhomologus chromosomes as seen in the figure. The
figure displays the combinations that are possible for this particular cross of alleles.
M.C. Question: Which of the following is NOT true of
autopolyploidic individuals?
a. It is a result of a failure of meiosis during gamete
production
b. It can double chromosome number from the diploid
count (2N) to a tetraploid number
c. The offspring of a tetraploid and a diploid would result in
a sterile triploid
d. It begins with 2 different species interbreeding and
combining their chromosomes
FRQ: A woman pregnant with twins got into a severe car accident causing her to need many X-rays. The doctors
were concerned that the radiation would be harmful to the children and therefore, performed a DNA test on the
unborn children. The data indeed revealed a mutation in the DNA of both individuals, however, when the first child
was born, no signs of abnormalities were present. The second child showed signs of a non fatal heart condition.
Explain the conditions that caused the mutation to not affect the first child. Then, explain how the second child’s
mutation negatively contributes to genetic variation.
M.C. Question: Which of the following is NOT true of autopolyploidic individuals?
a. It is a result of a failure of meiosis during gamete production
b. It can double chromosome number from the diploid count (2N) to a tetraploid
number
c. The offspring of a tetraploid and a diploid would result in a sterile triploid
d. It begins with 2 different species interbreeding and combining their chromosomes
FRQ: A woman pregnant with twins got into a severe car accident causing her to need many Xrays. The doctors were concerned that the radiation would be harmful to the children and
therefore, performed a DNA test on the unborn children. The data indeed revealed a mutation
in the DNA of both individuals, however, when the first child was born, no signs of abnormalities
were present. The second child showed signs of a non fatal heart condition. Explain the
conditions that caused the mutation to not affect the first child. Then, explain how the second
child’s mutation negatively contributes to genetic variation.
The first baby’s DNA is a result of a silent mutation. The mutation found within the baby’s DNA
is present in the noncoding regions of the DNA. An example of noncoding region of DNA
includes introns that are snipped out during transcription. The second child now has a gene
present that causes the heart defect. Once the child reaches reproductive age, if he/she were
to reproduce, he/she could pass on the gene to it’s offspring, continuing to add genes to the
gene pool. This gene being present in the gene pool will cause negative effects for the
hereditary line of the individual especially since the gene is non fatal and will not be as likely
to be selected against.
LO 3.29: The student is able to construct and explanation of how viruses introduce genetic variation in host organisms.
SP 6.2: The student can construct explanations of phenomena based on evidence produced through scientific practices.
Explanation: Viruses identify appropriate cells to infect by binding to specific receptors. It is possible for them to cross species or
be tissue-specific. Due to the effective capability of replication, viruses are able to evolve fast and acquire new phenotypes.
Some viruses are able to integrate into the host DNA and create a latent (lysogenic) infection. This results in new properties for
the host cell. An example of this would be pathogenicity in bacteria. During the lysogenic cycle a virus is able to weave into host
cell DNA, called a temperate phage, and replicate viral and own DNA. “New” viruses are able to emerge through the mutation
of an existing virus since there is no proofreading. An example of a virus that has no proofreading or checking mechanism is an
RNA virus. Related viruses can combine/recombine information if they infect the same host cell. Viruses transmit DNA or RNA
when they infect a host cell. HIV is an example of a commonly known virus within the host that contributes to the pathogenicity
of viral infection. Since HIV is a retrovirus it reproduces through reverse transcriptase, which is where RNA is brought back to
DNA. Helper T cells are attacked within our immune system. These processes of the lysogenic cycle and retroviruses introduce
genetic variation in the host organism since the host’s DNA now includes this new DNA from the virus.
M.C. Question: Some double-stranded DNA viruses can reproduce by two mechanisms including the lytic cycle and the
lysogenic cycle. Which of the following statements best explains the difference between these two mechanisms?
A) The lytic cycle is that of a bacteriophage while the lysogenic cycle is that of a temperate phage because it is weaved into host
cell DNA.
B) The lytic cycle kills the host cell while the lysogenic cycle replicates the
phage genome without destroying the host.
C) The end result of the lytic cycle is the phage genome is packaged inside
the capsid and absorbed, and the result of the lysogenic cycle is the DNA
molecule is incorporated by genetic recombination into a specific site in
the chromosome of the host cell.
D) Under certain conditions the lytic lifestyle can switch to a lysogenic
lifestyle.
Learning Log/FRQ-style Question: Suppose that E. Coli infects a cell by a phage. In
terms of lysis discuss the infection cycle and its effects. How is genetic variation
established? Why is this important?
ANSWER KEY-LO 3.29
Some double-stranded DNA viruses can reproduce by two mechanisms including the lytic cycle and the lysogenic
cycle. Which of the following statements best explains the difference between these two mechanisms?
A) The lytic cycle is that of a bacteriophage while the lysogenic cycle is that of a temperate phage because it is
weaved into host cell DNA.
B) The lytic cycle kills the host cell while the lysogenic cycle replicates the phage genome without destroying the
host.
C) The end result of the lytic cycle is the phage genome is packaged inside the capsid and absorbed, and the result
of the lysogenic cycle is the DNA molecule is incorporated by genetic recombination into a specific site in
the chromosome of the host cell.
D) Under certain conditions the lytic lifestyle can switch to a lysogenic lifestyle.
Suppose that E. Coli infects a cell by a phage. In terms of lysis discuss the infection cycle and its effects. How is
genetic variation established? Why is this important?
The infection of an E. Coli cell begins when the phage binds to the surface of the cell and injects its DNA. The
DNA molecule is then incorporated into a specific site on the host cell’s chromosome by genetic recombination,
or crossing over. The viral DNA is then known as a prophage. When the E. Coli is preparing to divide it replicates
the phage DNA along with its own and then passes the copies on to the daughter cells. The viral DNA of the E.
Coli is able to weave itself into the DNA of the host organism, which introduces genetic variation. The host’s
DNA now includes this new E. Coli DNA from the virus. Just one single infected cell can quickly give rise to a
large population of bacteria that is carrying the virus in prophage form. It is important for the lysogenic cycle to
establish genetic variation because it can help us characterize the molecular basis of attenuation of viral
vaccines and further know about the origins of viruses.
A. LO 3.34 The student is able to construct explanations of cell communication through cell-to-cell direct contact
or through chemical signaling.
B. The student can construct explanations of phenomena based on evidence produced through scientific practices.
C. LO 3.34 focuses on cell communication through cell-to-cell direct contact and chemical signaling. Cell communication through cell-tocell direct contact involves communication of cells that are directly touching each other. For example, the plasmodesmata of plant cells,
open channels in the cell walls of a plant through which strands of cytosol connect from an adjacent cell, serve as passages for materials to
be transported from cell to cell. The plasmodesmata directly connect plant cells together. Cell communication through chemical signaling
is accomplished through signaling over short distances and signaling over long distances. An example of short distance signaling is
signaling between neurons with neurotransmitters.
Neurotransmitters leave the axon terminals of the pre-synaptic neuron, travel through a very short gap that separates the neurons, called the
synapse, and enter into the dendrites and cell body of the post-synaptic neuron. Chemical signaling between cells over long distances is
called endocrine signaling. Endocrine signals are produced by endocrine cells that release signaling molecules, which are specific and can
travel long distances through the blood to reach all parts of the body. An example of an endocrine signal is insulin, it is a chemical that is
released by the pancreas that then travels through the bloodstream to the liver and causes liver cells to store glucose as glycogen, thus
decreasing blood glucose levels.
D. Cell communication through direct contact has been inhibited in some of the cells in an organism. What could be a possible explanation
as to why cell communication has been blocked?
a. The cells do not have enough neurotransmitters.
b. The cells’ plasmodesmata have been blocked.
c. The organism’s bloodstream has been functioning incorrectly.
d. The organisms organs do not contain enough endocrine chemicals.
e. Both A and D.
E. Communication between cells is vital in the survival of organisms.
a. Identify and explain two types of cell communication.
b. Discuss how cells communicate with chemicals over short distances and over long distances.
F.
G. ANSWER KEY
Multiple-choice question answer: b. The cells’ plasmodesmata have been blocked.
FRQ-Style essay question answer:
a. Cell communication can be accomplished through either cell-to-cell direct
contact or through chemical signaling.
In cell-to-cell direct contact communication, cells are physically touching each
other and materials are
transported through the cells. An example of cellto-cell direct communication is the transport of materials
through the plasmodesmata of
plant cells. In cell communication through chemical signaling, cells release
chemicals
to one another in order to communicate. An example of chemical signaling between cells is
the
transfer of neurotransmitters from one neuron to another.
b. Cells can communicate over short distances by sending neurotransmitters
between neurons and they can
communicate over long distances by
secreting chemicals and hormones into the bloodstream with the endocrine
system.
When neurons release chemicals to communicate with other neurons, the neurotransmitters
travel
through only a short gap, the synapse, to reach the other neuron. The dendrites
and cell body of the neuron then
receive the neurotransmitters and send the same
neurotransmitters to even more neurons. The endocrine system
aids in long distance
chemical signaling. Endocrine cells release a chemical into the bloodstream, then travels to
a target cell that receives the chemical, and then the cell responds to the
chemical. For example, when blood
glucose is too high, pancreatic cells release insulin
that travels through the bloodstream and is received by liver
cells. The liver cells
then store glucose as glycogen, lowering blood glucose levels.
Learning Objective 2.2
•
•
•
•
•
The student should be able to justify a claim that free energy is required for living
systems to maintain organization, to grow or to reproduce, but that multiple
strategies exist in different living systems.
Using mathematical ways to solve problems using numerical data given from natural
phenomena.
Energy is required for reproduction, photosynthesis, the 10% rule of energy
consumption, or even normal bodily or even bacterial functions using these multiple
strategies mentioned, that can be mathematical routines given from these processes,
for us to help or simply watch organization being maintained.
What is required for living systems to grow, reproduce, or maintain organization
while using it in many different ways?
A) Niches
B) Energy
C) Grass
D) Internet
Discuss how that humans use energy to maintain organization and provide an
example.
Multiple Choice and FRQ Answer Key
• MC- B, Energy is required for living systems to
reproduce, grow, and maintain organization.
• FRQ- We are endotherms which means we use
thermal energy to maintain homeostasis of our
body temperature. Whenever we eat food and
our body begins to break that food down
breaking down the glucose into energy.
Metabolism uses enzyme-catalyzed reactions that
allow organisms to grow, reproduce, maintain
their structures, and respond to their
environment.
LO 3.39: The student is able to construct an explanation of how certain drugs affect signal reception, and consequently, signal
transduction pathways.
SP 6.2: The student can construct explanations of phenomena based on evidence produced through scientific practices.
Explanation: Molecules such as drugs, hormones and neurotransmitters that bind to a receptor are called ligands. Drugs affect
signal transduction and reception by acting as ligands in the process of chemical signaling. A ligand may activate or inactivate a
receptor. Receptors are macromolecules, which can be located on the cell surface membrane or within the cytoplasm. Activation
of a receptor can increase or decrease a cell function, such as DNA transcription, enzyme activity, protein phosphorylation etc.
Most drugs have relative selectivity, meaning they act as ligands that can bind to a few different but similar receptors.
Pharmacology is a scientific practice that proves this process to be valid, because drugs are designed to target specific receptors in
order to elicit a cellular response via a transduction pathway.
MCQ: A psychiatrist believes he can mitigate some of his schizophrenic patient’s symptoms if he can lower the level of dopamine in
the patient’s brain. Biologically, how would the prescribed drug effectively decrease the level of this neurotransmitter?
A) An agonist would be prescribed to increase reuptake of excess dopamine.
B) An agonist would activate dopamine receptors and decrease cellular functions, including reuptake.
C) An antagonist would deactivate dopamine receptors upon ligand binding.
D) An antagonist would bind to the neurotransmitter molecules and transport them across the plasma membrane.
E) Both C and D
FRQ: Explain in detail how the effect of a drug on a signal transduction pathway differs from the effect of a hormone on a signal
transduction pathway. Be sure to include a comparison of the responses generated and how the molecules enter the pathway.
Answer Key
•
•
Multiple choice answer: B – An agonist is a molecule that combines with a receptor on a cell to trigger a
physiological reaction. In order for the drug to lower the level of dopamine, dopamine receptors must be
blocked from the reuptake of dopamine. To do so dopamine receptors can be activated, however the
activation must decrease the cellular function of reuptake.
FRQ answer: A drug enters the body directly to the blood stream if injected, or diffuses through the
stomach lining/ lining of the small intestine, into the blood stream, if ingested orally. Hormones are made
in the glands of the endocrine system before entering the blood stream. Both drug and hormone
molecules travel through the circulatory system to reach cells with appropriate receptors for ligand
binding to occur. Depending on the drug molecule’s structure it will bind to either a G protein-linked
receptor, a tyrosine kinase receptor, or a ligand gated ion channel, when acting as a ligand. Hormone
molecules bind to hormone receptors and pass easily through the cell membrane when acting as a ligand
because they are non-polar. Transduction is the conversion of the received signal to a specific cellular
response. Following reception both hormones and drug molecules act as relay proteins in their respective
pathways. These relay proteins lead to the activation of second messengers, such as cAMP and Ca+2,
downstream that go on to elicit specific responses later in the cycle. The responses generated by the
reception and subsequent transduction of hormones and drug molecules can actually be the same, the
difference being that the response to the hormone was generated by the body for homeostasis and the
response to the drug was elicited by man, usually for a medical purpose.
LO 3.12: The student is able to construct a representation that connects the process of
meiosis to the passage of traits from parent to offspring.
SP 1.1: The student can create representations and models of natural or man-made phenomena and systems in the domain.
SP 7.2: The student can connect concepts in and across domain(s) to generalize or extrapolate in and/or across enduring
understandings and/or big ideas.
Explanation: Meiosis, like mitosis, is involved in cellular division. However, meiosis
is the replication of gametes. rather than somatic cells. Meiosis is divided into two
phases; meiosis I and meiosis II. The major event in meiosis I is the separation of
homologous chromosomes. The major event in meiosis II is the separation of
sister chromatids. Unlike mitosis, meiosis produces haploid cells that contain a
haploid number of chromosomes, often expressed as “n”. Due to factors such as
independent assortment and crossing over, the fusion of any male gamete with
any female gamete has 64 trillion possible diploid combinations.
FRQ Question: Describe how the events in the different stages of meiosis
are evolutionary advantages.
Multiple Choice Question: Which of the
following is not true regarding meiosis?
I: Genetically identical daughter cells are
produced.
II: Four daughter cells are produced.
III: There are few possible diploid
combinations.
A)
B)
C)
D)
I, II, III
I only
I, III
II, III
Answer Key
Multiple Choice Question: Which of the
following is not true regarding meiosis?
I: Genetically identical daughter cells are
produced.
II: Four daughter cells are produced.
III: There are few possible diploid
combinations.
A) I, II, III
B) I only
C) I, III
D) II, III
Example of acceptable drawing
FRQ Question: Describe how the events in the
different stages of meiosis are evolutionary
advantages.
5 total points possible.
1 point: Description of
independent assortment
1 point: Description of random
fertilization
1 point: Description of crossing
over
1 point: Student describes why
genetic variation is favorable in
nature
1 point: Elaboration (graphs,
charts, drawings, etc.). Must
be in addition to at least one
of the possible points above.
LO 3.21- The Student can use representations to describe how gene regulation influences cell products and functions.
SP 1.4 The student can use representations and models to analyze situations or solve problems qualitatively and quantitatively.
Explanation: Brain and liver cells contain some DNA but their functions are vastly different. This is due to gene regulation, which turns
“on” and “off” certain genes like a master control switch; this effects the expression of the genes in the cell and influences the cell products
and the overall function of the cell. Gene regulation happens at many different levels, for example the DNA level or the RNA level. At the
DNA level, for example, there is DNA methylation, which turns on a switch that puts coatings on sections of DNA with methyl groups and
Histone acetylation, which when switched on unwinds DNA for easier translation. DNA methylation is when methyl groups are added to the
cytosine and adenine to block all biochemical processes that would be exacted on that segment of DNA or gene. At the RNA level there is the
activation of transcription with proximal and distal control elements and enhancers and silencers. All the regulators at the RNA level effect
transcription. In eukaryotes, the control of transcription depends on the binding of activators to DNA control elements. For example before
the start of transcription an activator protein binds to the distal control element, which forms an enhancer (activator). Then a DNA-bending
protein bends the DNA and helps it connect to general transcription factors at the TATA/Promoter region of the strand. This will eventually
initiate RNA synthesis. The different combinations of control elements affect what genes are expressed on the strand of new RNA. After the
mRNA is processed and translated by a ribosome the protein is formed it will be sent off to do work. This is done when a strand of mRNA is
read and each codon assembles amino acids into sequences that when combined in certain ways give a cell its structure. The overall
quaternary structure of the protein produced determines the overall function of the cell. The shape affects function and the function
determines where a cell may be placed within the body. These different gene regulators, regulate what genes are expressed which when
translated makes many different kind of proteins. This allows brain cells and liver cells, which both contain the same genome, to have very
different functions and produce different things that the body needs.
M.C. Question – Which of the following regulations of gene expression occurs at the DNA level?
A) DNA methylation turns off a switch for sections of RNA and puts caps or coatings on the RNA with methyl groups that
are a key process in regulation of gene expression.
B) Proximal and distal elements bind upstream from the promoter, effect the gene expression.
C) DNA creates a protein that is degraded because it is tagged by ubiquiden to be engulfed by Protosomes.
D) Enzymes called histone acetylation; acetylate lysine amino acids on histone proteins by transferring an acetyl group from
acetyl CoA to form N-acetyl lysine as a important part of gene expression.
Learning Log/FRQ Style Questions- Answer
How do RNA splicing, repressor proteins and methylation affect the regulation of a protein synthesis?
Learning Log/FRQ Style Questions
M.C. Question Answer – Which of the following regulator of gene expression occurs at the DNA level?
A) DNA methylation turns off a switch for sections of RNA and puts caps on the RNA with methyle groups, which
is a key process in regulation of gene expression.
B) Proximal and distal elements bind upstream from the promoter, effect the gene expression.
C) DNA creates a protein that is degraded because it is tagged by ubiquiden to be engulfed by Protosomes.
D) Enzymes called histone acetelyation, acetylate lysine amino acids on histone proteins by transferring an
acetyl group from acetyl CoA to form N-acetyl lysine as a important part of gene expression.
FRQ Answer: Spliceosomes remove introns from the mRNA sequences, and at the same time fuse together the left over exons.
This leaves the mRNA with a useable sequence that can be run through a ribosome and turned into a protein that can be used
somewhere in the body. Repressor Proteins inhibit both transcription and translation, by binding to inhibitory sites on cells that
carry out both transcription and translation. This binding to protein’s inhibitory sites causes the gene to become silent or go on
unexpressed in the cell. This inactivation of gene expression can be reactivated at a later date, but only if the necessary chemical
or environmental factors are present in the cell. And finally DNA methylation or Histone methylatoin prevents the replication of
those DNA segments that are methylated. These are also known as Barr-bodies. The methylation of certain DNA and mRNA
sequences prevents restriction enzymes from accessing the sequences. If they are never able to access the sequences then they can
never be cut and processed into proteins for synthesizing.
LO 4.5: The student is able to construct explanations based on scientific evidence as to how
interactions of subcellular structures provide essential functions.
SP 6.2:The student can construct explanations of phenomena based on evidence produced through
scientific practices.
Explanation: Ribosomes are an example of subcellular components combining to form an important
structure. Protein and ribosomal RNA interact to form ribosomes, the site of protein synthesis. The
30S subunit and 50S subunit are the two complexes of RNA and protein that make up the ribosome,
and these subunits are known as the large and small subunits. Once these components combine the
ribosome can take the genetic message carried by mRNA from the nuclear DNA and translate the
message to create specific polypeptides. Bound ribosomes are attached to the endoplasmic reticulum,
forming the rough ER. The endoplasmic reticulum and lysosomes are other organelles that
demonstrate the importance of interactions between subcellular structures in completing essential
processes. The endoplasmic reticulum is formed by a combination of the smooth and rough ER,
while lysosomes must fuse with other organelles in order to complete some types of digestion.
M.C. Question: Which of the following statements about lysosomes is not true?
A) The interior of the lysosome must have a pH of 5 in order to protect the contents of the cytosol from
unregulated digestion
B) Lysosomes fuse with food vacuoles during phagocytosis in order to digest food
C) Lysosomes fuse with the mitochondria during respiration in order to digest food
D) During autophagy lysosomes fuse with vesicles in order to engulf
disabled organelles
Learning Log/FRQ-Style Question: Many organelles interact in order to carry
out essential functions. Describe the structure and function of two organelles
that work together in order to perform an essential process and describe
the process.
ANSWER KEY- LO 4.5
Which of the following statements about lysosomes is not true?
A) The interior of the lysosome must have a pH of 5 in order to protect the contents of the cytosol
from unregulated digestion
B) Lysosomes fuse with food vacuoles during phagocytosis in order to digest food
C) Lysosomes fuse with the mitochondria during respiration in order to digest food
D) During autophagy lysosomes fuse with vesicles in order to engulf disabled organelles
Many organelles interact in order to carry out essential functions. Describe the structure and
function of two organelles that work together in order to perform an essential process and
describe the process.
Lysosomes and food vacuoles work together in order to complete digestion. Lysosomes are
membranous sacs of hydrolytic enzymes used by animal cells to digest macromolecules.
Food vacuoles are formed by phagocytosis and have no basic shape, as that depends on
the needs of the cells, meaning that they are basically enclosed structures that are filled
with water and molecules. Lysosomes carry out digestion with hydrolytic enzymes that
digest the food particles. One way that lysosomes carry out digestion is by engulfing
smaller organisms, a process known as phagocytosis. During phagocytosis the food
vacuole fuses with the lysosome, where the enzymes digest the food. The fusing of these
two components allows the enzymes to properly digest the food.
LO 4.21: The student is able to predict consequences of human actions on both local
and global ecosystems.
SP 6.4: The student can make claims and predictions about natural phenomena
based on scientific theories and models.
Explanation: An ecosystem is all the organisms in a given area as well as the abiotic factors with which they interact (a
community and its physical environment). Ecosystems are surrounding us, and are all over the world. In an ecosystem,
biotic factors such as plants and animals interact with the abiotic factors such as air, water, and minerals to create a
balanced environment. Biotic factors evolve and adapt over time to make them better suitable to survive in the
ecosystem they’re in, with the resources that they are provided. Humans, however, are capable of throwing off this
balance and cause disruptions in ecosystems. Humans are altering our ecosystems locally and globally on a daily basis.
Whether we realize we’re changing ecosystems or not, a lot of human interactions with them can cause consequences
on the ecosystem based on how humans are interacting with it. Humans can change ecosystems with factors such as
climate change as a result of burning fossil fuels and other gasses, and by introducing new and invasive species into an
ecosystem that throws off its balance. These are just two of the many ways in which humans can alter ecosystems, and
they can be done on local and global levels.
M.C. Question: Human interactions with an ecosystem can alter it
and make it unstable. Which change in an ecosystem stated below
is not an example of the consequences of human actions?
A)A decrease in available resources for plants and animals in the
ecosystem
B)The reduction of certain species due to a sudden increase in
predation
C)A gene mutation which leads to the development of a new species
D)Less biodiversity due to the alteration of the ecosystem
Learning Log/FRQ style question: Ecosystems can be altered by
many factors, one of them being the actions of humans. All of these
actions can have consequences. Name 2 human actions that can
alter an ecosystem, and describe the consequences that would
come from them.
ANSWER KEY- LO 4.21
•
•
•
•
•
M.C. Question: Human interactions with an ecosystem can alter it and make it unstable. Which change in
an ecosystem stated below is not an example of the consequences of human actions?
A)A decrease in available resources for plants and animals in the ecosystem
B)The reduction of certain species due to a sudden increase in predation
C)A gene mutation which leads to the development of a new species
D)Less biodiversity due to the alteration of the ecosystem
Learning Log/FRQ style question: Ecosystems can be altered by many factors, one of them being the actions
of humans. All of these actions can have consequences. Name 2 human actions that can alter an ecosystem,
and describe the consequences that would come from them.
Ecosystems could be affected by humans if they were to urbanize an area within the ecosystem. This would
have very negative consequences on the ecosystem, because by clearing the land, they are getting rid of
many animals habitats, and diminishing the plants and animals resources for survival. This would cause
many animals to have to find new homes, and could result in the death of some plants as well (especially if
trees are torn down). A second way in which human actions can affect an ecosystem is if they enter an
ecosystem and expose the animals in it to a foreign disease that the humans could be carrying. If a disease
that the animals are not immune to is introduced, it may cause many of them to die from sickness. This
would affect not only the animal population, but the ecosystem as a whole, because it cannot function
properly without animals. If one animal (or multiple within the same species) were to die, it could
potentially cause a disruption within the entire food web the animal was in. The predator/prey cycle would
be altered, causing a change in the ecosystem. The disease could also begin to spread to other neighboring
ecosystems, causing a disruption in multiple, and possible even on a global level.