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EOCT Review Questions
Introduction
1. What is the ultimate goal of science? Developing an understanding of the natural universe which is
free of human bias.
2. How are universal principals discovered in science? Obervations, Research – design and do
experiments
3. What are possible sources of bias in research? Instrument error – ex. not calibrated correctly,
measurement error, researcher error
4. What is the fastest way to get new research out to the research community? The World Wide
Web! (Must be careful with the data!) Journal publications are also important because many
require a peer review.
5. What are some examples of how theories have changed and why? World is flat, center of universe;
spontaneous generation, etc. These change due to better technology, a new understanding of what
the data represents, etc.
6. Why do scientific problems rely on the “design and execution” of new experiments? It may
reinforce or weaken opposing explanations.
7. What is anthropomorphism and how can it affect research? Attribution of human motivation,
characteristics, or behavior to inanimate objects, animals, or natural phenomena. It assumes that
everything “works” the way we do… adds tremendous bias to research!
8. Know lab safety!!!!!
Part I
1. What does the term biology mean? The study of life.
2. What are the steps to the scientific method in order? 1: Make observations and ask questions.
(Define the problem.) 2: Gather background information. (Research, this is where you educate
yourself to make the “educated guess”! 3: Develop a hypothesis 4: Test the hypothesis
(experiment, collect data, and analyze data) 5: Draw conclusions and identify new questions 6:
Communicate the results: Publish findings – subject to peer review
3. What is the difference between independent and dependent variables? The independent
variable is what the experimenter is manipulating. What the independent variable affects is
called the dependent variable. Ex. Fertilizer would be the independent variable and the rate of
plant growth would be the dependent variable.
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4. What is the main tool of the biologist? Microscope
5. What do the following branches of biology study?
Botany – plants
Ecology – the interactions of organisms with their environments
Genetics – heredity
Microbiology – microorganisms
Taxonomy – classification
Zoology – animals
Part II
1. What are the three main ideas of the cell theory? 1) All cells come from pre-existing cells 2)
The cell is the basic unit of structure and function 3) All living things are composed of one or
more cells.
2. What are the characteristics of life? 1) composed of cells 2) reproduce using a universal
genetic code 3) growth and development 4) obtain and use materials and energy 5) (uses
energy to) maintain homeostasis (stable internal environment) 6) as a group, change over time
7) respond to stimuli
3. What is homeostasis and how is it important for living organisms? Maintaining internal balance
or equilibrium. Organisms must respond and adjust to environmental stressors such as
temperature, sunlight, chemicals and other organisms. Cells must regulate water, glucose,
nutrients and wastes. The membrane it essential in maintaining a cellular homeostasis.
4. How do eukaryotes differ from prokaryotes? Eukaryotes have a nucleus and other membrane
bound organelles and prokaryotes do not have a nucleus and other membrane bound organelles.
(Both have DNA, cell membrane, cytoplasm and ribosomes) Additionally, eukaryotic cells can
assemble into multicellular organisms.
5. Describe the fluid mosaic model of the cell membrane. The model used to describe the cell
membrane as a fluid bi-layer of phospholipids with proteins embedded through out and cell
makers on the outside.
6. Explain how the cell membrane regulates cell behavior. The cell membrane is selectively
permeable regulating what enters and exits the cell. (Maintaining homeostasis!) The membrane
has different chemical receptors embedded on its surface allowing certain chemicals to target
it while allowing other cells to ignore the chemicals. Ex. Nerve cells: chemical in the
bloodstream causes the nerve cell to respond to a stimulus and leaves other cell unaffected.
Hormones work this way as well!
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7. Fill in the following chart of cell organelles:
Organelle
Function
Nucleus
Nuclear envelope
Ribosomes
Mitochondria
Chloroplast
Endoplasmic
Reticulum
Golgi Apparatus
Cell membrane
(a.k.a. Plasma
membrane)
Control center of the cell. Contains the
DNA.
Regulates what enters and exits the
nucleus. Has nuclear pores.
Function in translation of protein
synthesis (makes polypeptide chains
which become proteins!)
Carries out cellular respiration.
Generates energy (ATP) from glucose
Captures solar energy and makes glucose
during photosynthesis using the pigment
chlorophyll
Membraneous channels which transport
materials within and out of the cell
Modifies, packs and ships materials
(proteins and lipids) out of the cell by
pieces pinching off (vesicles) and fusing
with the cell membrane.
A flexible, phospholipid bi-layer
embedded with proteins which regulates
what enters and exits the cell.
Prokaryotes or
Eukaryotes?
Eukaryotes
Animal cells or
Plant cells?
Both
Eukaryotes
Both
Both
Both
Eukaryotes
Both
Eukaryotes
Plant
Eukaryotes
Both
Eukaryotes
Both
Both
Both
Plant, Bacteria,
Fungi, and
some Protista
(never
animals!)
Both
Cell Wall
Rigid structure which provides additional
support and protection for some cells.
Both
Cytoplasm
Cellular mixture of water and dissolved
substances and organelles found within
the cell but not including the nucleus.
Both
8. How is active transport different form passive transport? Active transport requires the use of
energy (going against the concentration gradient – uphill) to move materials across the cell
membrane (endo- and exo- cytosis) and passive transport does not require energy (going with
the concentration gradient – down hill) to move materials across the membrane (osmosis,
diffusion, and facilitated diffusion). Ex. of active transport: Sodium potassium pump
9. Explain/draw endocytosis and exocytosis. Endocytosis – the use of energy to move larger
particles into the cell. 2 Types: phagocytosis – extensions of the cell membrane surround and
pull in large particles, creating a vacuole (cell eating). pinocytosis – a pinching in of the cell
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membrane bringing smaller particles into a vesicle (cell drinking). Exocytosis is the opposite of
endocytosis, it is the use of energy to remove larger particles from the cell.
10. Define each of the following:
Diffusion – The movement of molecules from an area of higher concentration to an area of
lower concentration. (Passive transport – going with the gradient)
Osmosis – The movement of water through a semi-permeable (or selectively permeable)
membrane going from an area of higher concentration to an area of lower concentration.
(Passive transport – going with the gradient)
Facilitated diffusion – The movement of molecules across the cell membrane through carrier
molecules/protein channels. Ex. glucose Does not require energy – passive transport!
Isotonic – Solution on both sides of the cell have the same concentration of dissolved
substances (solute). Water move into and out of the cell evenly – equilibrium is already
established.
Hypertonic – Solution on the outside of the cell has more solute (dissolved substances) than
inside the cell. Water will move out of the cell to establish equilibrium.
Hypotonic – Solution on the inside of the cell has more solute than outside the cell. Water will
move into the cell to establish equilibrium.
Part III
1. Why is water important in biology? WATER IS POLAR! Universal solvent, moderates climates
(holds heat), cools through evaporation, freezes from the outside in, adhesive (attracted to
other things – allows for capillary action, and cohesive (attracted to other water molecules).
2. What is hydrogen bonding? How is it important in DNA? A weak bond formed from the
attraction of a positive hydrogen on one molecule to a negative part of another molecule. Holds
the base pairs of DNA together, also creates unique properties of water.
3. What is the pH range of acids? Of bases? Acids: 0-6.9 ex. citric acid Bases: 7.1-14 ex.
bleach *7 is neutral ex. water
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4. Differentiate between endergonic and exergonic reactions. Endergonic: More energy is put
into the reaction than comes out of the reaction. The products have more energy stored in the
bonds than the reactants. Ex. Photosynthesis. Exergonic: More energy comes out of the
reaction that was put into the reaction. The products have less energy that the reactants. Ex.
Cellular respiration
5. Fill in the chart of 4 main organic compounds:
Organic compound
Monomer
How are they used?
Carbohydrate
monosaccharide (simple quick energy
sugar)
ratio of atoms:
1C:2H:1O
Lipid
glycerol and fatty acids
Made up of C, H, and
O but less O than
carbs.
Protein
amino acids
*contains nitrogen
**polypeptide chains
Nucleic Acid
nucleotides (composed
of a 5 C sugar,
phosphate group, and a
nitrogen base)
cell membrane, energy
storage, shock
absorber, insulation (non
polar – insoluble in
water!)
build structure and
support, immune system,
and enzymes, O2
transport
heredity and making
proteins
*coenzymes
Example:
glucose, sucrose, starch,
glycogen, cellulose
(monosaccharides,
oligosaccharides, and
polysaccharides)
fats, oils, waxes and
steroids
*waxes are long fatty
acid chains attached to
an alcohol.
antibodies, muscle,
collagen, hemoglobin,
insulin
DNA and RNA
ATP, ADP, NAD+ and
NADP+
6. What are enzymes? How do they regulate the rate of reactions? STRUCTURE IS RELATED
TO FUNCTION! Enzymes are proteins which function as a catalyst. They speed up the rate of
reactions by reducing the amount of activation energy required to start the reaction but are
not used up or permanently altered in the reaction. The substrate binds with the active site of
the enzyme, the reaction occurs and the products are released. Enzymes work in both
directions. *Enzymes are very specific for the substrate/reaction they facilitate. This is
called the Lock and Key Model . Ex. lipase helps with the digestion of lipids. The concentration
of the enzyme can determine the rate of the reaction. Ex. Dilute the enzyme and the reaction
rate slows, add more enzyme and the reaction rate speeds up . Some serious genetic disorders
are caused by faulty critical enzymes (the genetic code for the enzyme has an error). Ex. Tay
Sachs Disease and PKU (phenylketoneuria).
7. How can you tell from the name of a compound that it is an enzyme (usually)? A sugar? Name of
enzymes tend to end with –ase, names of sugars tend to end with –ose.
8. Explain the following three factors that affect enzymes: pH, temperature, and salinity. Give
examples.
 Enzymes tend to be specific for the pH they work in like trypsin and pepsin in digestion.
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 Most enzymes denature at high temp.: Fresh pineapple can not be used in Jello but canned
pineapple can due to the fact that the canning process heated and denatured the enzymes that
would otherwise stop the Jello from gelling. This is also why high temperatures are dangerous
when you get sick! Cold temperatures do not denature the enzyme but slow down molecular
activity. That is why we put things in the refrigerator. The cold slows down the chemical
activity of the bacteria, etc. that want to break down our food, given time the food will still go
bad!
 Most enzymes will not work in a high salt concentration: this is why salt is often used as a
preservative, stops/slows bacterial decomposition!
9. What is it called when a protein unravels? Denature
10. Fill in the following chart to compare photosynthesis and cellular respiration.
Process
Organelle where
What is needed? What is
it occurs
produced?
Photosynthesis
chloroplasts
CO2, H2O, and
glucose and O2
sunlight (photons)
Cellular
mitochondria
glucose and O2
CO2, H2O and
Respiration
energy (ATP)
Overall equation
6CO2 + 6H20 ->
C6H1206 + 02
C6H1206 + 02 ->
6CO2 + 6H20
11. What is fermentation? Why and does it occur? The breakdown of glucose (sugar) to release
energy (ATP) in the absence of oxygen. Occurs in the cytoplasm of a cell. In humans this
occurs in the muscle cells producing lactic acid which causes cramps and soreness! In other
organisms it produces alcohol. Very inefficient! Only produces a net total of 2 ATP’s!
12. What are the stages of photosynthesis, where do they occur in the cell, and what is produced in
each stage? The light reaction = “Photo” and the Calvin cycle = “synthesis”
Stage of photosynthesis
Where it occurs
Produced
Light reaction
thylakoid membrane
O2 (waste from breaking down
(Traps light)
water), ATP, NADPH
Calvin Cycle
Stroma
Simple sugars, PGAL
(Fixes carbon)
13. What are the stages of cellular respiration, where do they occur in the cell, and what is
produced in each stage? Food is the source of heterotrophs energy. The digestive system (we
have an entire system designed to get us energy!) breaks down food and blood brings glucose to
the cells where it diffuses into the cells with the help of insulin (facilitated diffusion).
Stage of cellular respiration
Glycolysis
Acetyl CoA production
Krebs Cycle
Electron Transport Chain and
chemiosmotic phosporylation
Where it occurs
cytoplasm
inner space of mitochondria
membrane
Matrix
Cristae
Produced
pyruvic acid, 4 ATP but used 2
Acetyl Co A, 2 CO2
4 CO2, NADH, FADH, 2 ATP
32 ATP; NAD+ and FAD+ (to be
recycled in the Krebs cycle)
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*the CO2 is a waste product, oxygen is the ultimate electron acceptor at the end of the electron
transport chain and becomes a part of water.
14. What is ATP? What is it used for? Adensosine Triphosphate. ATP and ADP are nucleotides!
Unstable, high energy molecule used to do cell work.
15.
What happens when a phosphate is removed from ATP? What happens to the ADP?
Energy is transferred from one molecule (energy intermediate molecules) to another
(*phosporylation). Like playing hot potato! The ADP goes back a cycle to get recycled by having
a P added back on to make it ATP!
ATP ↔ ADP + P + E
*bioluminescence – the production of light through a series of chemical reaction by a living
organism. Ex. lightning bugs, many deep-sea organisms. The reactions are powered by ATP!
16. In a chemical equation, where are the reactants? (left or right side?) where are the products?
The reactants are on the left side of the equation and the products are on the right side of the
equation. Ex. C6H1206 + 02 -> 6CO2 + 6H20
reactants
products
Part IV
1. List the steps of the cell cycle (NOT the steps of mitosis). G1 phase: cell growth, S phase:
DNA replication, G2 phase: growth and preparation for cell division, Mitosis: PMAT, and
Cytokinesis: division of the cytoplasm
2. What happens during Interphase? The cell grows, adds organelles. May also undergo
preparation for cell division (includes G1, S, and G2 phases)
3. What happens during mitosis? The nucleus divides. Keeps the number of choromosomes
constant from one cell generation to the next. Purpose: Allows eukaryotes to grow and repair
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tissues. Ex. Skin grafting: burn victims can have a small piece of healthy skin removed and
cultured. The new skin is used to cover the burned areas. Mitosis is also used for asexual
reproduction such as budding, binary fission, regeneration, etc.
4. What happens during cytokinesis? The cytoplasm divides. In animal cells, the cell membrane
pinches inwards. In plant cells, a cell plate forms which will become the new cell wall.
5. What are the 4 main stages of mitosis (in order)? Prophase, Metaphase, Anaphase, and
Telophase Purpose: to make an exact copy of the cell!
6. Describe what is happening in the stages of mitosis:
Stage
Description
Prophase
DNA coils into chromosomes and are visible, spindle fibers from and radiate across the
cell, and the nuclear membrane starts to break up
Metaphase
The duplicated chromosomes line up randomly in the center of the cell between the
spindles at the equator.
Anaphase
The duplicated chromosomes are pulled to opposite ends of the cell. Every chromosome
that was present in the parent cell is now represented by the daughter chromosome at
the poles.
Telophase
The nuclear membrane forms around the chromosomes at each end of the cell. The
spindle fibers disappear and the chromosomes disperse and become less distinct.
7. What is the purpose of meiosis? The purpose is to produce gametes with ½ the number of
chromosomes (haploid - n) compared to the parent cell (diploid - 2n). Additionally, the
chromosomes have been modified through crossing-over and are genetically different (genetic
recombination) from the parents’.
8. Define haploid and diploid. What is the human haploid and diploid number? Haploid (n) – ½ the #
of chromosomes, cell only contains one set. Diploid (2n) cell contains both sets (maternal and
paternal) of chromosomes. Humans: haploid = 23; diploid = 46
9. Compare sexual reproduction and asexual reproduction. Sexual: offspring are genetically
different that the parents, requires 2 parents/fusion of gametes. Asexual: offspring are
“clones”, genetically identical to the parent cell.
10. Fill in the chart to compare mitosis and meiosis.
Starts with
Ends with
# of stages
Mitosis
1 diploid cell
1 phase: 4 stages
Somatic cells or
sex cells?
somatic
Meiosis
1 diploid cell
2 phases: meiosis
I and meiosis II –
8 stages
sex cells = egg
and sperm
(gametes)
2 diploid (2n)
cells
4 haploid (n) cells
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11. What is a gamete? Is it haploid or diploid? How are sperm and egg formation different? A
gamete is a sex cell, either an egg or a sperm. Gametes are haploid. Spermatogenesis: the
formation of sperm through meiosis results in 4 sperm cells. Oogenesis: the formation of an
egg through meiosis results in 1 egg cell (ova) and 3 polar bodies. The difference is due to
unequal division of the cytoplasm.
12. Who is Gregor Mendel? Austrian Monk who predicted how traits are carried from one
generation to the next. Father of Classical Genetics.
13. What organism did Mendel study?
Garden pea; these plants reproduce
sexually and have both the male and
female parts in each flower.
Mendel could manipulate the flower
parts and control fertilization. (He
would cut off the stamen and select
the pollen himself!) He did multiple
crosses and mathematically
determined the probability of traits
occurring in the F1 and F2
generations from the parental
cross.
Mendel's experimental plants were
a flowering species of the pea, or
Leguminosae family, called Pisum
sativum, or garden peas. The
drawing illustrates the basic
structure of a flower, as in Pisum.
The flower can be considered the
specific part of, or site in, the plant
where reproduction takes place.
14. Define the following terms:
Dominant – the allele that determines phenotype with respect to a particular gene.
Recessive – the allele that has no noticeable effect on the phenotype unless the dominant allele
is not present.
Gene – a “factor” located on a chromosome that occurs in pairs and determines the trait.
Alleles – alternative forms of a gene found on different copies of chromosomes, one from mom
(maternal) and one from dad (paternal).
gametes – sex cells; egg and sperm – haploid.
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monohybrid crosses – genetic crosses involving one trait.
dihybrid crosses – genetic crosses involving two traits.
Phenotype – the expressed trait of an organism.
Genotype – the genetic makeup of an organism.
Heterozygous – having two different alleles for a gene.
Homozygous – having two identical alleles for a gene.
15. Define the following laws of Mendel:
 Law of Dominance: some alleles are dominant and others are recessive.
 Law of Segregation: A general rule in inheritance that individuals have two alleles for each
gene, and that when gametes form by meiosis, the two alleles separate, and each resulting
gamete ends up with only one allele of each gene.
 Law of Independent Assortment: A general rule in inheritance that when gametes form by
meiosis, each pair of alleles for a particular characteristic segregate independently.
16. Explain how Mendel’s laws are observed in meiosis. Each pair of homologous chromosomes line
up on the equator in any order and are separated from each other during the first division
which reduces the cell chromosome number by half. (Maternal chromosomes can mix with
paternal chromosomes)
17. Explain three ways in which genetic variation can occur. 1) crossing over – non-sister
chromatids of homologous chromosomes exchange pieces of DNA. 2) independent assortment –
maternal and paternal chromosomes or alleles segregates independently. 3) random
fertilization – chance at which sperm will fertilize which egg.
18. What are the sex chromosomes for human females? For human males? Female: XX Male: XY
19. What is crossing over? When does this occur? ) crossing over – non-sister chromatids of
homologous chromosomes exchange pieces of DNA. It occurs during Prophase I of meiosis.
20. Complete the following cross using a Punnett Square and give the genotypic and phenotypic
ratios:
Tt x Tt
T
t
T TT Tt
Tt
tt
t
genotype: ¼ TT, ½ Tt, ¼ tt
phenotype: ¾ tall, ¼ short
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21. DNA and RNA are made up of nucleotides. What are the 3 parts of a nucleotide? Draw and
label a nucleotide. sugar, nitrogenous base (adenine, thymine, guanine, cytosine, uracil), and
phosphate group
22. What is the function of DNA? RNA?
DNA: stores and transmits genetic
material from one generation to the
next. Contains the codes for protein.
The order of the nucleotides forms the
unique genetic inforomation of an
organism. RNA: makes up the ribosome
and carries the code for a protein from
the nucleus to the ribosomes in the
cytoplasm.
23. What are the 4 different bases in DNA?
adenine (A), thymine (T), guanine (G), and
cytosine (C)
25. How is DNA different from RNA?
24. What is the structure of DNA? Which
scientist determined the structure?
Double Helix; James Watson, Francis
Crick, Maurice Wilkins (and Rosalind
Franklin!)
*DNA
*RNA
double stranded
single stranded
contains thymine
contains uracil
long
short
found in the nucleus found in nucleus and cytoplasm
sugar: deoxyribose sugar: ribose
26. Describe how DNA is replicated. DNA is “unzipped” by enzymes (polymerase) which breaks the
hydrogen bonds between the nitrogen bases and free nucleotides are brought in following base
paring rules using each side as a template. Replication is considered semi-conservative because
each new strand is made of a ½ new and ½ old sides. Each new strand is a complement of the
original.
27. Where does DNA replication take place? In the nucleus.
28. What is a mutation? What are some causes of mutations? A change in the nucleotide sequence
(genetic code) of DNA; how the resulting protein interacts with other proteins and its
environment will dtermine if the mutation is harmful, neutral, or beneficial. (Natural selection
will occur!) Leads to variation, the ultimate source of genetic diversity (can lead to evolution!)
Some are Spontaneous – they just occur due to errors during replication and recombination; ex.
a mistake in enzyme repair “fixes” the wrong base. Others causes of mutations include
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mutagens such as X-rays (ionizing radiation), ultraviolet light, free radicals, and chemicals
(drugs such as those found in tabacco plants).
29. Define karyotype. Why/when would you use a karyotype? A picture of the chromosomes
arranged by size. Used to determine chromosome abnormalities.
30. Explain the following genetic tests: amniocentesis, chorionic villi sampling. Amniocentesis: a
sample of the fluid (amniotic fluid) surrounding the fetus is withdrawn by inserting a needle into
the mother’s abdomen and into the uterus. The fluid contains fetal cells that have been
sloughed off from the skin and mouth cavity. The cells are cultured until there are enough to
do a karyotype. Chorionic villi sampling (CVS): A piece of the a membrane called the
chorionic villi, which is made from fetal cells, is removed by way of the vaginal tract. The cells
are then cultured to do a karyotype.
31. Explain nondisjunction. Nondisjunction is an accident in meiosis or mitosis in which a pair of
homologous chromosomes or a pair of sister chromatids fail to separate at anaphase. This
results in cells having too many chromosomes or not enough. Ex. Down’s Syndrome is due to a
failure of chromosome 21 to separate resulting in 3 chromosome 21’s in the zygote. The cell
that was missing chromosome 21 would not be able to survive/develop if fertilization occurred.
32. Describe the following chromosomal mutations by using diagrams: translocation, inversions,
duplications and deletion. Translocation: a piece of one chromosome breaks off and attaches
to a nonhomologous chromosome. Inversion: A piece of a chromosome breaks off and
reattaches backwards. Duplication: A repeating part of a chromosome resulting from fusion
with a fragment from a homologous chromosome. Deletion: A part of a chromosome is lost.
33. Describe the following point mutations or gene mutations (mutations which cause a change in
the nucleotide sequence of a DNA molecule) by using nucleotide bases (ATCG’s): deletions,
substitutions, and insertions. What is a genetic disorder caused by a substitution? Deletion is
the loss of a single nucleotide base in a strand of DNA, substitution occurs when one base is
replaced with a different base in a strand of DNA, and an insertion is when a base is added to
the strand of DNA.
ex. Substitution: exchanging an A for a T in the DNA that codes for hemoglobin is the cause of
sickle cell disease.
Normal DNA code:
ATCGATCGATCG
Deletion:
A*C G A T C G A T C G
Insertion:
A T*T C G A T C G A T C G
Substitution:
A G*C G A T C G A T C G
Ex. of genetic disorders caused by a substitution is Sickle Cell Disease and Cystic Fibrosis!
34. What is meant by stating that point mutations may shift the reading frame? Since every three
letters codes for an amino acid (codon), by changing the order of the three letters, new codons
are read. Usually these new sequences are different enough from what was supposed to happen
that when formed, the protein is nonfunctional.
Frameshift mutations – caused by
ex. The cow jumped over the moon becomes
insertions or deletions are usually
more serious than substitutions!
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The coj umpedo vert hem oon.
35. How can we use our knowledge of DNA in forensics? in medicine? in agriculture? We use DNA
samples taken from crime scenes to try and identify the people involved. In medicine, we use
our ability to insert human DNA (genes) into bacteria and then the bacteria follow the
instructions coded for in the DNA. This is how we make insulin, growth hormone, etc. In
agriculture, we use DNA to make genetically modified foods which have better nutritional value,
crops with higher yield of produce, animals that are healthier, etc.
36. Describe the function of each type of RNA
mRNA – formed in the nucleus using a DNA template. Carries the instructions, “recipe,” out to
the ribosomes. Formed in the process known as transcription.
tRNA – found in the cytoplasm. Picks up specific amino acids and brings them to the ribosome
to be used in the formation of the protein. Each tRNA is specific for the amino acid it will
carry and follows base paring rules to ensure that the right amino acid is added by matching its
anticodon with the mRNA codon.
rRNA – Coded for by DNA as well, used in the formation of the ribosome. Helps produce
enzymes needed to bond amino acids together during protein synthesis.
37. What happens during transcription? The DNA unzips and free nucleotides in the nucleus join
together along one strand of the DNA and is released. The newly formed strand is mRNA. The
mRNA carries the message of the genetic code from the DNA in the nucleus to the ribosomes
in the cytoplasm.
38. Where does transcription occur? In the nucleus.
39. What happens during translation? The mRNA leaves the nucleus and moves into the cytoplasm
where the ribosomal subunits lock on to the mRNA and initiate the formation of the protein by
matching the codon on mRNA with the anitcodon on the tRNA which brings in the appropriate
amino acid. A peptide bond forms between the amino acids. Once a termination codon is
reached, the polypeptide (protein) is released.
40. What is a codon? 3 nitrogen bases on tRNA that carries a code for a specific amino acid. The
order of the amino acids determines the specific protein.
41. Where does translation occur? In the cytoplasm.
Part V.
1. Define the following terms:
Ecology – the study of how organisms interact with the environment. From the Greek word
“oikos” – which means house, and –ology, the study of.
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Ecosystem – all the organisms in a given area, along with the nonliving (abiotic) factors with
which they interact.
Biotic factors – a living component of an ecosystem. ex. plants, animals, fungi, bacteria, etc.
Abiotic factors – the nonliving components of a ecosystem. ex. water, soil, climate, light,
temperature, air, etc.
Community – an assemblage of all the organisms (several populations) living together and
potentially interacting in a particular area.
Population – a group of interacting individuals belonging to one species and living in the same
geographic area. They compete for food, water, mates and other resources.
Niche – a population’s role in its community. How they use the biotic and abiotic reasources.
The job! (What they eat, where they feed, and how they impact energy flow)
Habitat – a place where an organism lives. The address!
Producer – an organism which make organic food molecules from inorganic substances (CO2,
H2O). ex. plants, algae, chemosynthetic bacteria. (a.k.a. Autotrophs)
Consumer – an organism which relies on other organisms for its energy and food supply.
(a.k.a. Heterotrophs)
Decomposer – organisms which break down organic materials into inorganic ones. Major
recyclers of nutrients! Feed on dead bodies of animals and plants or on their waste products!
(ex. Dung beetles!)
Omnivore – an animal that eats both plants and animals.
Herbivore – an animal that only eats plants.
Carnivore – an animal that only eats animals.
Trophic level – the step in a food chain or a food web. Trophic structures show feeding
relationships in an ecosystem and shows the route of energy flow and pattern of chemical
cycling in an ecosystem.
Biosphere – The global ecosystem; that portion of Earth that is alive; all of life and where it
lives.
Population density – the number of organisms living in a given area.
Biodiversity – the variety of organisms, their genetic information and the biological communities
in which they live. (Divided into 3 types: Ecosystem diversity, Species diversity, and Genetic
diversity)
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Growth rate – the change in population size over a given amount of time. Can be positive,
negative or zero!
2. What does a food chain represent? Draw a simple food chain. Label the producer, primary
consumer and secondary consumer. A food chain is a simplified way to show/study the flow of
energy and matter through an ecosystem.
grass  cow  human
producer primary consumer
secondary consumer
(autotroph)
(heterotrophs)
3. How is a food web different from a food chain? A food web is a net work of interconnecting
food chains. (More realistic in an ecosystem)
4. What is the ultimate source of energy in our biosphere? the sun
5. List and explain the three types of ecological pyramids. Energy Pyramid: Shows the transfer
of energy through an ecoysystem, only 10% of the energy obtained at one level is available for
the next level up. Can be used to show how some populations will decrease at each level.
Biomass Pyramid: represents the amount of living organic matter at each trophic level.
Pyramid of Numbers: Shows the relative number of individual organisms at each trophic level.
6. Explain what happens the available energy as we move from one trophic level to the next trophic
level. (ex. from primary consumer to secondary consumer) Only 10% of the energy at one level
is available for the next level. 90% is both used by the organism or is changed into a form no
longer usable.
7. Draw a typical energy pyramid for the food chain you drew for question #2.
human (secondary consumer)
cow
(primary consumer)
grass (producer)
8. What is ecological succession? the process of biological community change resulting from
disturbance; transition in the species composition of a biological community. Ultimately, a
climax community, a stable community for that ecosystem, will exist. Disturbances include
flood, fire, volcanic eruptions, etc.
9. Compare primary and secondary succession. Primary succession occurs where life has not
existed prior to the pioneer species (lichens, mosses, etc.). Due to lack of soil. Pioneer species
must begin to form a soil base. Ex. Stone Mountain! Lava flows, areas from receding glaciers,
etc. Secondary succession occurs where a disturbance (fire, plowing, etc ) has destroyed the
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existing community but left the soil intact to that new communities can be established.
Secondary succession occurs much faster because base soil has been established.
10. What are conditions that lead to primary and secondary succession? Primary succession can
occur on newly exposed rock, lava flows, areas exposed after a glacier recedes, islands formed
from volcanic eruptions, etc. Secondary succession occurs when the already existing life is
destroyed by a disturbance such as fire, hurricanes, flood, man! and must restart.
11. What is a pioneer species and how do they prepare the area for the next species to arrive? The
first species to inhabit an area during primary succession. Pioneer species are hardy and can
live in harsh environments. As they go through their life cycles, they die, decompose and begin
to form the base of soil.
12. Explain the following nutrient cycles: Carbon, Oxygen, Nitrogen, Hydrogen and Phosphorus.
Carbon Cycle: Plants absorb CO2 from the atmosphere during photosynthesis and release CO2
back in to the atmosphere during respiration. Also, animals eat the plants and incorporate the
carbon into their bodies. Other animals, such as the fox, eat the rabbit and then use the
carbon for their own needs. These animals return carbon dioxide into the air when they
breathe, and when they die, since the carbon is returned to the soil during decomposition. Two
other important processes are fossil fuel burning. In fossil fuel burning, coal, oil, natural gas,
and gasoline are consumed by industry, power plants, and automobiles and the combustion
process puts CO2 into the atmosphere. This is a concern because of the accumulation of
atmospheric CO2 traps heat in the atmosphere and is altering the climate…global warming.
Oxygen Cycle: The oxygen of the atmosphere is almost completely the product of the
photosynthetic activity of green plants. The oxygen cycle works with the carbon cycle. Plants
and animals use O2 during cellular respiration and release CO2. The plants use the CO2 in
photosynthesis and release O2.
Nitrogen Cycle: 79 percent of the atmosphere consist of free nitrogen. This large reservoir
is not immediately available for plants. In this context, microorganisms have a central role.
Nitrogen fixation is the cue. This process converts the nitrogen into a form that plants can use,
ammonium and nitrate ions. (Nitrogen is needed for making proteins or nucleic acids.) Animals
eat the nitrogen and incorporate the plant’s nitrogen into their bodies. The animals die and
decompose ant nitrate and nitrite bacteria convert the amino groups back to nitrate or nitrite.
Nitrate-reducing bacteria living in the soil.
Phosphorus Cycle: Phosphorus is a part of DNA-molecules, molecules that store energy (ATP
and ADP) and fats of cell membranes. Phosphorus can be found on earth in water, soil and
sediments. Takes place in two different cycles. Phosphorus moves slowly from deposits on
land and in sediments, to living organisms, and than much more slowly back into the soil and
water sediment. Phosphorus is most commonly found in rock formations and ocean sediments as
phosphate salts. Phosphate salts that are released from rocks through weathering usually
dissolve in soil water and will be absorbed by plants. Because the quantities of phosphorus in soil
are generally small, it is often the limiting factor for plant growth. That is why humans often
apply phosphate fertilizers on farmland. Phosphates are also limiting factors for plant-growth in
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marine ecosystems, because they are not very water-soluble. Animals absorb phosphates by
eating plants or plant-eating animals. Phosphorus cycles through plants and animals much faster
than it does through rocks and sediments. When animals and plants die, phosphates will return
to the soils or oceans again during decay. After that, phosphorus will end up in sediments or
rock formations again, remaining there for millions of years. Eventually, phosphorus is released
again through weathering and the cycle starts over. The phosphorus cycle is one of the slowest
of the matter cycles. This process is so slow that phosphorus is considered non-renewable!
Hydrogen Cycle: hydrogen is one of the constituents of water. It recycles in conjunction with
the other biogeochemical cycles. It is actively involved with the other cycles like the carbon
cycle* (sometimes called the carbon/hydrogen cycle), nitrogen cycle, etc. Hydrogen is the most
common element in the universe and found in many organic compounds.
13. Why are nutrient cycles important? Matter is neither created or destroyed so it is important
to recycle and reuse. (Energy can not be recycled!)
14. What is the carrying capacity of a population? the largest number of individuals of an
population that a given environment can support and become stable. (Limiting factors are food,
water, space to live, waste, environmental conditions such as drought, etc.)
15. Differentiate between exponential growth and logistic growth.
exponential growth – occurs when the individuals reproduce at a constant rate. (Occurs under
ideal conditions.) Often called a “J-Curve”.
logistic growth – occurs when a population’s growth slows or stops following a period of
exponential growth. Often called an “S-Curve”.
green
line
red line
blue line
*red line shows the carrying capacity
*green line shows exponential growth
*blue line shows logistic growth
Exponential Growth
Logistic Growth – “Scurve”
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16. Differentiate between density dependent limiting factors and density independent limiting
factors. Density dependent limiting factors are affected by number of organisms in that area
(population density). For example: competition, predation, parasitism, crowding/stress.
Density independent limiting factors are occurrences and effects that are not affected by the
number or organisms living in the area. For example: weather, fire, droughts/floods, and human
activities.
17. Explain how humans have impacted the environment to cause acid rain and ozone depletion. Acid
rain is caused by emissions into the air from the combustion process, such as burning fossil
fuels, which release nitrogen and sulfur compounds which combine with the water vapor in the
air and make nitric and sulfuric acid which falls as acid rain. The compounds may drift for miles
before they fall. Ozone (O3) in the upper atmosphere protects life on Earth from the harmful
ultraviolet rays (a mutagen – causes mutation in DNA) in sunlight. Ozone depletion is caused by
chlorine released into the atmosphere by CFC’s (chlorofluorocarbons) found in freon, a
refrigerant, and propellants in aerosol cans, and in making Styrofoam. The chlorine reacts with
the O3 ozone reducing it to O2.
18. How has the use of pesticides, insecticides and herbicides impacted our environment? They
have encouraged resistant forms of the target species. Many have harmful side effects to nontarget species. Ex. DDT is stored in fat. Through a process known as biological magnification
(increasing in concentration at each tropic level as it is transported through food chains) DDT
built up in birds of prey (ex. eagle) and caused a thinning of eggshells. Young birds died before
hatching causing a rapid decline in the species.
19. Describe the characteristics of each of the following biomes:
Terrestrial:
 Tropical Rain Forest –
 Desert –
 Grassland –
 Temperate Forest –
 Taiga –
 Tundra –
Marine:
 open ocean –
 rocky intertidal zones estuariesFresh Water: (Only 3% of the water on earth is fresh water and of that 3%, 98% is frozen in
icecap!)
 lakes  rivers  streams  ponds 20. Define evolution. The change in an species over time.
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21. Define the following:
population genetics – mathematical descriptions of genetic phenomena to help researcher trace
evolutionary trends in populations.
adaptations – genetically coded traits that enable success in the environment by ensuring
survival through reproduction of the species.
speciation – evolution of a new species.
fitness – the ability of an organism to survive and reproduce sucessfully. The relative
reproductive efficiency of various individual or genotypes in a population. It involves a
combination of structure, physiology, biochemistry, and behavior.
phylogeny- a description of the lines of descent of plants and animals as they lived from one era
to the next. Ex. Horse (most complete line discovered.)
22. Explain the contributions of the following people: Charles Lyell, Thomas Malthus, and Alfred
Russell Wallace.
 Charles Lyell: Principles of Geology, 1) earth changed over time and 2) plant and animal species
had arisen, developed variations, and then became extinct over time.
 Thomas Malthus: The Principles of Populations; 1) populations outgrow food supplies and 2)
competition and struggle to survive.
 Alfred Russell Walace: Traveled to Brazil and SoutheastAsia; came up with a version of natural
selection based on competition for resources as the main focus. (Darwin’s was based on
reproductive success.)
23. Describe Lamarck’s theory of inheritance of acquired characteristics. Lamarck theorized that
organisms changed due to the demand of their environments (right on track!) He believed that
life could be placed on a ladder, The Ladder of Life, with each succeeding rung more advanced.
He proposed that by using or not using its body parts, an individual tends to develop certain
characteristics, which it passes on to its offspring. Ex. the giraffe acquired its long neck
because its ancestors stretched higher and higher into the trees to reach leave, and that the
animal’s increasingly lengthened neck was passed on to its offspring.
24. Was Lamarck correct? Why or why not? No Lamarck was not correct. For a trait or
characteristic to be passed from parent to offspring requires the information to be coded for
in the DNA.
25. Describe Darwin’s natural selection. *Natural selection is the mechanism that allows for
evolution. Within a varied population, individuals whose inherited characteristics adapt them
best to their environment are most likely to survive and reproduce; these individuals thus tend
to leave more offspring than less fit individuals do. Reproduction is central; the essence of
natural selection is differential, or unequal, success in reproduction. Two conditions: 1.
Species are dependent on the environment and 2. somehow reproductive isolation must occur.
(ex. due to geographical isolation, temporal isolation, behavioral isolation, etc. )
26. How can speciation occur? Describe the following types of isolation. Put a star by the one that
is essential for speciation.
a. geographical isolation – physical separation so population’s gene pools can not mix. Can be
caused by mountain ranges, lava flows, glaciers, etc.
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b. temporal isolation – “time” differences – occurs when species breed at different times (can
be day, seasons, years, etc).
c. **reproductive isolation – differences which keep fertilization from occurring (sperm and
egg can not get together or produce a viable zygote). Essential for speciation.
d. Behaviorial isolation – behaviors such mating dances, pheromones, etc.
27. Where did Darwin go as the naturalist on the H.M.S. Beagle and what observations did he make?
He went to the Galapagos islands and saw marine iguana that swam in the ocean and ate seaweed
(iguanas are usually land animals) and tortoises with unique shells. Other observations: went to
Patagonia and found fossilized bones of extinct sloths and giant armadillos.
28. What evidence supports the theory of evolution? Fossils, homologous structures (ex. bones in
the human arm and bones in the bats wing) as well as vestigal structures (ex. appendix, whale
pelvis remnants) biochemical evidence such as DNA and proteins, embryology (comparing the
stages of development of the embyro/fetus), geographical location (where they are located
relative to each other)
29. How is microevolution different from macroevolution? Microevolution is the change in a
population’s gene pool over a succession of generations. Can be caused by mutations, natural
selection, etc. ex. the Peppered Moth story was changing the frequencies of the genes for
color within the gene pool. Macroevolution refers to the main events in the evolutionary history
of life on Earth. This is usually done in terms of eras. (The big picture.)
30. Compare divergent, convergent and coevolution. Divergent evolution refers to organisms that
evolved from a common ancestor but over a long period of time have separated into different
groups. Ex. whales, bats and man. Convergent evolution is when species from different
evolutionary branches come to resemble each other (superficially) if they live in very similar
environments. Ex. bats and birds, whales and fish. Coevolution is the process by which two
species evolve in response to changes in each other over time. Ex. Flowering plants’ shape and
color and the specific type of pollinator they attract.
31. What is adaptive radiation? Give an example. A single species evolves into several different
species (diversity!) in a relatively short period of time. Ex. Darwin’s finches
32.
**Compare gradualism and punctuated equilibrium. Gradualism refers to when
populations evolve difference gradually as they become adapted to their local environments.
This is over very long periods of time (100’s of thousands of years). Punctuated equilibrium
refers to when a new species diverges from the ancestral lineage in a relatively brief time
followed by a long period of little change. Usually due to some major event (asteroid and
dinosaurs) which opens up new niches. Scientist hypothesize that there have been 5 major
mass extinctions!
33. Explain the five types of evidence that are used to show evolutionary relationships: biochemical
(DNA and proteins), fossil, homologous structures including vestigial structures and geographic
distribution. Fossils, homologous structures (ex. bones in the human arm and bones in the bats
wing) as well as vestigal structures (ex. appendix, whale pelvis remnants) biochemical evidence
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such as DNA and proteins (myosin: a protein found in our muscles which cause muscles to
contract is also found in the single-celled organism, yeast! In yeast it helps cell parts move),
embryology (comparing the stages of development of the embyro/fetus), geographical location
(where they are located relative to each other)
34. How do antibiotics and pesticides affect the evolution of bacteria, insects, etc. Coevolution!
The bacteria and pests that have a natural defense (due to variation within the species!) against
the poison survive and pass on the genes for the defense. Eventually, given time, the “pests”
that are left are resistant to the drugs/chemicals.
35. If you were to compare amino acid sequences, how could they show you an evolutionary
relationship? It is possible to estimate the phylogenetic (evolutionary) relatedness of two
species by inferring their molecular evolution from the differences in amino acids between
them. The more similar the amino acid sequences are the more related the organisms and the
closer they are on the evolutionary tree. The more differences between them the longer the
time that has passed and the less related the organisms are so they would be farther from each
other on the evolutionary tree.
Ex.
Ala-Gly-Phe-Try-Leu-Gly-Ala (amino acid sequence from dog)
Ala-Gly-Phe-Try-Leu-Leu-Ala (amino acid sequence from wolf)
Ala-Iso-Val-Asp-Leu-Cys-Ala (amino acid sequence from man)
36. What is a dichotomous key? a key for the identification of organisms based on a series of
choices between alternative characters
37. Use the dichotomous key to identify the following insects:
A.
B.
C.
D.
1. a. wings covered by an exoskeleton ………go to step 2
b. wings not covered by an exoskeleton ……….go to step 3
2. a. body has a round shape ……….ladybug
b. body has an elongated shape ……….grasshopper
3. a. wings point out from the side of the body ……….dragonfly
b. wings point to the posterior of the body ……….housefly
A.__________________________
C.__________________________
B.________________________
D.________________________
38. What is a cladogram? A cladogram is a tree-like diagram showing evolutionary relationships. Any
two branch tips sharing the same immediate node are most closely related. It does NOT
necessarily show the path of evolution.
39. Use the following cladogram to answer the questions after the diagram.
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a. Which group is the oldest? Bacteria
b. Which group(s) has/have large ribosomes? Eukaryota
c. Which group(s) has/have homeostatic controls within a cell? Bacteria, Archea, and
Eukaryota
Part VI
2. What purpose does the increasing complexity of the animal phyla serve? At each level the
organism become more complex adding organs and organ systems to maintain homeostasis. This
allows for more efficiency which leaves more energy for other activities. Organisms with
diverse systems are usually larger and are more mobile. Ex. The four chambered heart of birds
and mammals allows for better oxygenation of blood (oxygen is used to get energy in CR!) so
these animals can spend the energy to maintain a constant body temperature (warm-blooded)
compared to reptiles which have a 3-chambered heart and rely on the environment for their
body temperature.
There are pros and cons to increasing complexity: Pros stated above but cons include increased
gestation times (pregnancy), increased care of young, needs to spend more time feeding, etc.
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3. What are plant tropisms? Movement of plants due to a stimulus such as light (phototropism),
gravity (gravitropism), and touch (thigmotropism).
4. Explain how growth hormones cause plants to grow in the direction in which they do.
Plant hormones stimulate the growth of certain cells (in phototropism – the shady side is
stimulated by the hormone auxin which cause elongation of the cell). This creates pressure
because the opposite side does not grow, causing the plant to bend. Auxins also help promote
the growth of fruit and stop it from falling off. Many hormones such as gibbberellins, stimulate
the cell to undergo cell division (mitosis). Abscisic acid inhibits cell division!
5. What are some animal adaptations and how have they contributed to the success of the
animals?
 Innate behavior is inherited (can be both automatic or instinctive) such as reflexes,
territorial, migration, hibernation, estivation, mimicry, and camouflage,
 Some behaviors are learned such as habituation and imprinting. They provide changes that
make the organism more suited for the environment by increasing the chance for survival and
reproduction. (Natural selection and survival of the fittest)
 Adaptations for defense (mechanical and chemical) Ex. stingers, thorns, spins and venom,
odor from a skunk!
6. What are some plant adaptations and how have they contributed to the success of the plants?
Modified roots for energy storage (think potato! and any kind of plant bulb), adaptations for
seed dispersal (dandelion’s blowing in the wind, maple’s “helicopter”, cacti “hitchhikers”) and
pollination (flower color and smell), and seeds resistant to fire or thick bark to protect the tree
from freezing.
Part VII
1. List the six kingdoms and describe the major characteristics of both.
Eubacteria – Prokaryotic, single celled, live in harsh environments
Archeabacteria – Prokaryotic, single celled
Protista – Eukaryotic, single celled or multicelled, includes algae
Fungi – Eukaryotic, absorptive heterotrophs
Plantae – Eukaryotic, multicellular autotrophs
Animalia – Eukaryotic, multicellular heterotrophs
2. Explain why the kingdoms Eubacteria and Archeabacteria were separated from the single
kingdom Monera.
In the Archeabacteria, the cell walls, cell membranes, and ribosomal RNA are different from those
Eubacteria. Another difference is the absence of PEPTIDOGLYCAN, a protein-carbohydrate found in
the cell walls of Eubacteria. Additionally, Archaebacteria can live where no other organism can
survive. They live in extreme environments, such as acidic hot springs, near undersea volcanic vents,
and highly salty water.
The kingdom Eubacteria contain the organisms commonly called bacteria. They are classified by their
shape. Sphere-shaped eubacteria are called cocci. When cocci occur in chains, they are called
streptococci, grapelike clusters are called staphylococci, and sprial-shaped eubacteria are called
spirilla. Rod-shapped bacteria are called bacilli.
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