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HONORS BIOLOGY FINAL EXAM REVIEW 2009
Nondisjunction: The failure of one or more homologus pairs of chromosomes to separate during meiosis (could also occur if sister chromatids
fail to separate)
Monosomy: A genetic condition in which a cell receives only one chromosomes of a particular homologus pair (in humans, 45 chromosomes)
Trisomy: A genetic condition in which a cell receives an extra chromosome of a particular homologus pair (in humans, 47 chromosomes)
Polyploidy: A genetic condition in which a cell has 3 or more complete sets of chromosomes. It is a result of Nondisjunction occurring in all
the chromosome pairs (in hums, 69 chromosomes)
Autosome: Any chromosome other that a sex chromosome
Karyotypes (interpret them)- An image of a cell’s chromosome arranged by size and in homologus pairs (banging pattern and location of
centromere)- p arm is shorter leg of chromosome- q arm is longer leg of chromosome- always a male if there’s an Y (no matter how many X’s)
Amniocentesis and Chorionic Villi Sampling- During amniocentesis, Amniotic fluid is extracted through the mother’s abdominal and uterine
walls with a hypodermic needle- ultrasound monitoring watches the needle to avoid harming the fetus with the needle- takes a few minutes in
doctor’s office- results come back in 10-14 days- takes place between the 15th and 20th weeks-99+% chance of diagnosing Down Syndrome.5% miscarriage-During CVS, a small flexible plastic tube is inserted through the vagina and cervix to draw out chorin tissue- ultrasound is
used to avoid damage to the unborn child- tests take place between he 10th and 12th weeks- tests come back in 2 weeks or less- 98% chance of
diagnosing Down Syndrome- 1-3% miscarriage
Pedigrees (general rules for interpreting symbols on Autosomal recessive pedigree):
Sex-Linked recessive (X-linked)- trait is far more common in males- males cannot be carriers- daughters of males who have the trait
are either carriers or will have the trait- if the mother has the trait, so will any sons she has
Sex-Linked Dominant (X-Linked)- no carriers- daughters of a male who has the trait will also have the trait- no inheritance between
father and son (sons only inherit from mothers)
Autosomal Recessive Trait- males and females are equally likely to have the trait- traits often skip a generation- children can have the
trait if both parents are carriers
Autosomal Dominant Trait- no carriers- males and females are equally likely to have trait- traits do not usually skip a generation
-Circle is female- square is male- shaded if person has trait- half shaded if person is a carrier- not shaded if person does not have trait- anyone
who doesn’t have the trait must have at lease one dominant allele- children must have a recessive allele IF one of their parents had the traitboth parents must have a recessive allele IF any of their children had the trait
Genetic Disorders (symptoms and treatments):
Down Syndrome: trisomy 21- various levels of mental retardation- lower life expectancy- short body, enlarged tongue, stubby fingers,
head small and round- heart defects are common- fertile- likelihood increases as the mother’s age reaches late 30’s and 40’s
Klinefelter Syndrome: 47, XXY- occurs in males- usually sterile because cannot produce sperm- enlarged breast tissue, often lack
secondary sexual characteristics (facial hair, feminine body contours- slightly lower IQ’s- treatment may involve additional male sex hormones
Turner Syndrome- 45, XO- occurs in females- usually sterile because sex organs do not fully develop- short body and hands, stocky
build, sometimes extra folds of skin on the next, arms turn out slightly at elbows- secondary sexual characteristics may not fully develop
PKU: This disease occurs on the recessive allele. Patients lack the enzyme need to metabolize phenylalanine. Being unable to
metabolize this enzyme, people would produce toxic phenylketones that damage nerve cells in children. To lower risks of developmental
disabilities, mental retardation, or death, children keep a special diet that is low in phenylalanines until their brains are fully developed.
Cystic Fibrosis: This is a genetic mutation that occurs on autosomes on the recessive allele. This disease cause excess fluid to increase
around cells, creating a mucus substance. This mucus is thick and heavy, and clogs lungs, respiratory passages, and the digestive tract.
Treatments include mechanical vibrations to loosen the mucus, antibiotics to fight infection, management of diet, and experimental gene
therapy.
Huntington’s Disease: This disease occurs on autosomes on the dominant allele, which is extremely rare and unusual. Symptoms, such
as deterioration of the brain’s basal ganglia, loss of muscle control, twitching movements of limbs and body, loss of memory, and dementia,
aren’t shown until the late 30’s or early 40’s. The patient will die within 10 to 20 years once the symptoms have occurred, but because it’s a
genetic mutation, the allele could have already been passed on to their offspring.
Gel electrophoresis procedure and applications (including banding pattern): A process in which molecules are sorted by size as they are pulled
by an electrical current through a gel- used to see if restriction enzymes worked- Phosphate groups of DNA are negatively charged and
attracted to the positive charge of the electricity- Comb is inserted to make sample wells for DNA- agarose gel is a thick, porous, Jello-like
substance- nylon membrane secures the DNA fragments in the fragile gel
Restriction enzymes uses: Restriction enzymes are the “molecular scalpels” that allow genetic engineers to cut up DNA molecules in a
controlled way- they’re proteins that prevent, or restrict, invasion by foreign DNA- break DNA bonds at precise locations- 3 parts of their
names: 1. From the bacteria it was discovered from; 2. Which strand it comes from; 3. Number of enzyme found (Ex. EcoR1)
Recognition (restriction) sites: a 4 or 8 base pair sequence that is a palindrome. It’s where restriction enzymes recognize and cut at specific
places along the DNA molecule.
Restriction maps: A restriction map shows the location of cleavage sites for many different enzymes, so scientists can figure out where
restriction sites are. They are maps to the DNA molecule
Southern Blotting: A procedure in which DNA is transferred from a gel to a membrane filter and hybridized with a radioactive DNA probe- Xray film can be placed over the membrane to produce an autorad that mirrors the locations of the targeted DNA bands on the gel
Sticky Ends: A DNA fragment that has ends exposed to nucleotides at each end- When restriction enzymes cut a DNA molecule, the singlestranded tails are the sticky ends- They’re easy to rejoin to complementary sticky ends
PCR: Technique that uses DNA polymerase to make copies of a specific section of DNA (millions of copies of DNA can be copied in a matter
of hours). Primer is a short DNA or RNA fragment that anneals to single stranded DNA. It allows DNA polymerase to start replication the
DNA molecule- invented my Dr. Kary Mullis
Sex-Linked traits: Traits whose alleles are located on the sex chromosomes- in humans, many more alleles found on the X chromosome than on
the Y chromosome (X-linked…ex. Hemophilia, Colorblindness, Muscular Dystrophy)- if a genetic disorder involves recessive alleles
heterozygous females do not express the trait, but are carriers; females will only express the trait if they are homozygous recessive; because
males only receive one Z chromosome, they will express the trait if they have a recessive allele; more common in males; males inherit traits
from mothers- genotypes should include the sex chromosomes and the alleles are used as superscripts
Sex-limited traits: Alleles are located on the autosome- expressed in the presence of the sex hormones of one sex but not the other sex (ex. Milk
production in female mammals, color of plumage in male birds)
Sex-influenced traits: Alleles are located on the autosomes- expressed in both sexes, but differently- involves responses to sex hormones (ex.
Baldness
DNA fingerprinting: Technique that compares the pattern of DNA bands from a suspect, produced during gel electrophoresis, with the pattern
of bands from the DNA evidence- Every DNA sample has its own unique apttern- can be used for identification
Plasmid: A small, circular piece of DNA found in bacteria (separate from the chromosome)- small circular pieces of DNA within bacteria
Recombinant DNA: DNA that contains fragments derived from 2 or more different sources- Using sticky or blunt ends, the complementary
nitrogenous bases match and to another DNA strand creating a DNA strand from 2 or more sources
Selective Breeding:
Cloning: Technique that produces an individual that is genetically identical to another organism (in many animals, it involves inserting DNA
from a body cell into an egg cell)
Transformation: Process of inserting recombinant DNA into a living cell (usually involves a vector)
Gene Therapy: The practice of inserting functional genes to do the work for nonfunctional genes
Transgenic Organisms: An organism that has been genetically engineered to contain DNA from different species
Short tandem repeats (or VNTR): They consist of simple, repetitive sequences of DNA found mainly in the intergenic regions of a
chromosome. They tend to differ from person to person are often used to produce the “DNA fingerprint”
Barr Body:
Applications and objectives of the Human Genome Project:
Objectives: map the entire base sequence of every chromosome in the human cell- identify all the genes in the base sequencedetermine what proteins the genes code for- determine the exact role of each gene- identify the gene location and base sequence for genetic
diseases
Applications: diagnosis of specific genetic diseases (Ex. PKU) and screen for a position to other diseases (other types of cancer)- help
produce drugs and proteins to treat specific genetic diseases- increases the ability to research the effects of mutations of genes- increases our
understanding of evolution and taxonomic relationships- gives insight into the structure, function, and organization of DNA in chromosomes
Medical Benefits: improved diagnosis of disease and predisposition to disease by genetic testing- better identification of disease
carriers, through genetic testing- better drugs can be designed using knowledge of protein structure rather than by trial and error- greater
possibility of successfully using gene therapy to correct genetic disorders
Non-medical Benefits: greater knowledge of family relationships through genetic testing- advances forensic science through the
analysis of DNA at crime scenes- improved knowledge of the evolutionary relationships between humans and other organisms, which will help
to develop better- more accurate classification systems
Ethical issues: it is unclear whether 3rd parties have rights to genetic test results- if treatment is unavailable for a disease, genetic
knowledge about it may have no use- genetic tests are costly, and there is no easy answer as to who should pay for them- genetic information is
hereditary so knowledge of an individual’s own genome as implications for members of their family
Genetically Modified Foods issue (advantages and disadvantages):
Advantages: first applications increased cop yields by designing plants that were resistant to pests and therefore reduced the use and
expense of harmful pesticides- engineer plants that are capable of degrading weedkillers (Roundup) so that crops are not harmed when spraying
for weeds- improve nutrional value of crops (Golden Rice with beta-carotene)- extend the shelf life of produce (tomatoes, bananas)Bioremediation-engineer plants that are capable of removing large quantities of toxic substances from the soil- in the future, design crops that
contain edible vaccines
Disadvantages: plants engineered to produce natural pesticides present 2 potential problems: 1. some species of insects could evolve a
resistance to the pesticide and actually make it more difficult to control pest problems (evolution); 2. Presence of pesticides could harm
beneficial, non target species- Superweeds-transgenic plants can hybridize 9cross pollinate) with closely related wild plants. If these wild plants
were to acquire the genes that made them resistant to weedkillers, they might crowd out other important species of plants and disrupt the
ecosystem- genetically modified foods could trigger an allergic reaction in unsuspecting individuals if they carried genes for an allergen from a
different food. Detractors call them “Frankenfoods” and worry that they will pollute the food supply with new and toxic chemicals- cloning of
plants and animals reduces the genetic diversity of population. Genetic variation is the goal of sexual reproduction. Variation is good in
changing environments and reduces catastrophic losses from disease susceptibility- Not what God made- Prices
Golden Rice: Beta-carotene produces Vitamin A- 250 million people suffer from Vitamin A deficiency- 1/2 million go blind each year- 1/2 the
world’s population depends on rice- Scientists inserted the beta-carotene gene into rice, giving it the golden color of daffodils- this is
recombinant DNA, a form of genetic engineering
Bt Corn: Bacillus Thuringiensis- lives in soil- the genes in BT bacterium are important so they can be inserted in other cells- it’s safer than
pesticides because it’s natural- caterpillars, first stage of life for Monarch butterflies, are affected and killed by it- Superbugs that are resistant
to Bt Corn will evolve and eventually not be affected by this natural pesticide
Fitness: An organism’s ability to survive and reproduce in a particular environment
Gradualism: States that small evolutionary changes occur slowly and steadily over long periods of time- the process yields many transitional
forms
Punctuated Equilibrium: states that a population tends to remain relatively stable for long periods of time interrupted by periods of relatively
rapid evolutionary change- explains gaps in the fossil record
Stabilizing Selection: favors individuals with the intermediate phenotype (most common variation in the population) because they are more fit
than those with extreme phenotypes (less common variations in populations)- evolution is minor or absent- Ex. Weight of human infants
Disruptive Selection: favors individuals with the extreme phenotypes that deviate in both directions from the population average. Both of the
extreme phenotypes have higher fitness than the intermediate phenotypes- evolution into 2 populations with distinct traits- Ex. Beak size in
African finches
Directional Selection: favors individuals with an extreme phenotype because they are more fit than all the other phenotypes- evolution more in
a specific direction- Ex. Size of human brains, size of horses, color of peppered moths
Variation (and mutation): Differences that exist between members of the same species (the raw material of evolution)- Ex. Size, color, blood
type
Inbreeding: crossing of genetically similar organisms to maintain the presence of certain desirable traits- tends to increase homozygous
genotypes for both desirable and undesirable traits- Ex. Purebred dogs are more likely to have joint deformities and blindness
Outbreeding (hybridization): crossing of genetically dissimilar organisms to bring together the best of both organisms- tends to increase
heterozygous genotypes and vigor (health).
Adaptation: An inherited trait that helps an organism survive in its environment- a beneficial variation- Ex. Structural, behavioral,
physiological
Natural Selection: process in which organisms with favorable variations are more likely to survive and reproduce. These variations are passed
onto the next generation- Ex. Antibiotic resistance in bacteria
Population: a group of organisms of the same species that live in the same area
Analogous structure: refers to the part of 2 different species that are similar in function, but not in structure- Ex. Wings of a bird and wings of a
butterfly
SCIENTISTS:
Malthus- 1798 wrote an “Essay on the Principle of Populations”, Essay stated that human babies were being born faster than people were
dying. He noted that the human population could outgrow their resources, such as living space and food supply. States that factors such as war,
famine, and disease help keep population in check. Darwin will apply these principles to all organisms- not all of those born will survive, those
that survive will have to compete for limited resources
Lamarck: 1809- Believes the fossil record shows evolution has occurred and presents a theory to explain it. Theory includes Tendency Toward
Perfection, Use and Disuse, and Inheritance of Acquired Characteristics
Lyell: 1830-1833 book entitled “Principles of Geology”- Lyell studied geologic deposits and determined that geologic forces (erosion, glaciers,
etc.) showed that earth was shaped by slow, progressive changes, not catastrophic events (e.g. floods). Therefore, Earth much be millions of
years old (necessary for Darwin’s explanation of evolution)- He stressed that scientists must explain past geologic events in terms of processes
that can actually be observed today (uniformitarianism)- Although Lyell rejects the idea of evolution for most of his life, he accepts it in the
early 18h60’s and becomes a close friend and defended of Darwin
Darwin: 1809-1882- sailed on the ship HMS Beagle as its naturalist from 1831-1826. He collected numerous samples and fossils. In the
Galapagos Islands, he studied finches, tortoises, and iguanas. The diversity of these species greatly influenced his thinking on evolution. In
1859, he published the book “On the Origin of Species by Means of Natural Selection”- never uses the word ”evolution”, instead Descent With
Modification
Wallace: 1823-1913- developed a theory of evolution nearly identical to Darwin’s (“On the Tendency of Varieties to Depart Indefinitely from
the Original Type”). He sent a copy to Darwin, asked for some advice, and told him that he was going to present his theory. This motivated
Darwin to also present his research and theory to the Linnaean Society in 1858
Cuvier: 1769-1832- Prominent scientist who studied fossils and was instrumental in the development of paleontology (particularly vertebrate).
He also plays a key role in proving that extinctions did occur, He believes these are a result of periodic catastrophes (revolutions). He does not
believe in evolution, he believes species are immutable (fixed and unchanging). He explains that after a catastrophe, species immigrate from
other regions to repopulate those areas. Does not go as far as to suggest new creations after each catastrophe
Bonnet: 1720-1793- (discovered parthenogenesis in aphids). Observed that fossilized organisms did not resemble modern organisms. He
supported the idea of “evolution”, however he believed that there was an “evolutionary ladder”. Bonnet believed organisms perished in
periodic, worldwide catastrophes that wiped out all life- organisms were brought back after “stepping up” a rung the “evolutionary ladder” Ex.
Apes became humans, humans became angels
Morgan:
Bateson and Punnett:
Sutton:
Evidence of Evolution:
Fossils: the preserved remains or traces of ancient organisms- most accurate representation of the history of life on earth, the fact that
the types of fossils present have changed over time implies that life on earth has changed over time (evolution)- many species that are alive
today have no corresponding fossils during much of earth’s history. Implies that more recent species must have evolved from older speciesyounger fossils are usually more similar to modern organisms than are the older fossils. Often the fossil record shows transitional forms that
reveal a progression of evolutionary changes- the earliest fossils are all unicellular organisms and the most complex are found most recently in
fossil record- many species that were alive in the past are not alive today
Homologus Structures: compares structures found in different species that are similar in structure, but not necessarily similar in
function- structures are similar to each other because they evolved from a common ancestor for both species
Vestigial Structures: structures that have no or a reduced function in organisms- these structures evolved from an ancestor that had a
greater need for them- difficult to explain their existence without evolution
Comparative Biochemistry: compares the DNA and proteins of different species to see how similar they are- closely related species
have similar DNA because they evolved from a common ancestor- the genetic code is universal because organisms have a common ancestor- at
some point in time, chromosome number 2 combined 2 chromosomes to make the human chromosome 2. there is a remenance of telomeres.
Now humans have 23 airs, but chimps have 24
Biogeography: studies the distribution of organisms in different parts of the world- explains why regions that are separated by large
physical barriers, but that have similar environments, wound contain different species rather than the same species- this occurred because
population evolved differently in one region than they did in another
Lamarck’s Theory of Evolution: organisms constantly strive to improve themselves and become more advanced- the effort to improve cause
the most used body structures to develop, while unused structures waste away- once a structure is modified by use or disuse, the modification is
inherited by the organism’s offspring
Darwin’s Theory of Evolution: there is variation within populations. Many variations are inherited and such traits are passed from parent to
offspring- some variations are favorable, improving the organism’s ability to function and reproduce in its environment- more young are
produced in each generation than can survive. Only a few survive long enough to reproduce (competition)- organisms that survive and
reproduce are those with favorable variations. Because the offspring of these individuals will inherit favorable variations, a larger and larger
proportion of each new generation will have these variations (natural selection)- over enormous periods of time, small changes accumulate, and
population change (gradualism).
Procedure radiometric dating: rock or fossil may contain elements that are radioactive. The decay (breakdown) of these radioisotopes occurs at
a constant rate and can therefore be used a geologic “time clock”. The parent isotope breaks down, through a series of steps, to form a daughter
product. Scientists use the ratio of parent isotopes to daughter product to determine how many half-lives have passed and then calculate how
old the same is. The age is given in years- A half life is the length of time it takes for exactly one-half of the parent atoms to decay to daughter
atoms- Ex. Carbon 14 dating, Potassium 40 dating, Rubidium 87 dating, Uranium 238 and 235 dating- Axioms: the rate of decay of a
radioactive isotope is measurable and constant; the isotopes of an element appear in a mineral in precisely the same ratio as they occurred in the
environment; when an atom undergoes radioactive decay, its internal structure and chemical behavior change- Assumptions: we can determine
the amount of parent isotope present when it was formed; leaching of the parent isotope out of the rock did not occur; the daughter product was
not present when the rock formed nor was the rock contaminated by an infusion of the product- x=ln (n+)
x= number of half lives passed
____No
N+=parent isotope remaining
ln (.5)
No= parent isotope originally
ln= natural log
Bryophyte characteristics:
Rhizoid: A root-like structure that anchors nonvascular plants
Gamete: sexual reproductive cell- Ex. egg, sperm
Embryo:
Capsule: A small sac that contains spores in mosses (spore case of a moss plant)
Spore: A haploid reproductive cell that germinates without being fertilized
Sporangia: A spore case
Antheridium: A male reproductive structure that produces flagelled sperm (in nonvascular plants)
Archegonium: A female reproductive structure that produces a single egg (in nonvascular plants)
Frond: The leaf of a fern sporophyte
Prothallus: The gametophyte of a fern (it is heart shaped)
Sorus: A cluster of sporangia (spore cases) in ferns (often found in the underside of the frond)
Tracheophytes: vascular plants
Gemmae: Cuplike structures in liverworts that contain haploid cells capable of asexual reproduction
Xylem: Vascular tissure that transports water and minerals throughout parts of a plant
Phloem: Vascular tissue that transports dissolved sugars and starches
Alternation of generations (including haploid and diploid stsages)- process in which plants switch between haploid (n) and diploid (N) stages of
their life cycle
Challenges and benefits of plant colonizing land:
Nucleotide- monomers of nucleic acids- makes up DNA- consists of three parts: deoxyribose, phosphate groups, and a nitrogen base- 4
different kinds
Leading strand- The DNA strand that replicates in the direction that follows the movement of the replication fork (continuous
synthesis occurs)
Lagging strand- the DNA strand that replicates in the direction opposite the movement of the replication fork- DNA forms in
fragments that later are connected by DNA ligase
Antiparallel- The sugar-phosphate backbone of the 2 DNA strands run in opposite directions
Histones- Proteins that bind to DNA and helps to fold DNA into chromatin (human DNA would be 3 ft long if not folded)
Nucleosome- structures that may help to package and fold DNA- structures that may play a role in regulating the way genes are
transcribed
Primase (RNA polymerase)- An enzyme that synthesizes the RNA primer and attaches it to the parent DNA strand (the template)
at the origin of replication
RNA Primer- A sequence of approximately 10 nucleotides that are complementary to the parent DNA- it’s attached at the origin
of replication and allows DNA polymerase to bind to the DNA template strand
Semi conservative model- Describes the arrangement of the DNA strands that altar replication (parent/daughter, daughter/parent)
Purines- large nitrogen bases- Adenine and Guanine
Pyrimidines- small nitrogen bases- Thymine and Cytosine
Continuous and discontinuous synthesis:
Continuous:
Discontinuous synthesis- way of lagging strand replication- DNA doesn’t replicate continuously- made by Okazaki
fragments
Operon-A group of genes that are expressed together because they have related functions
- Ex. 3 lac genes in E. coli code for 3 enzymes that breaks down lactose
Promoter- A region of DNA where RNA polymerase attaches (starting point for transcription)
Repressor- A proteins that prevents RNA polymerase from attaching to the promoter
(prevents transcription)
Operator- Region of DNA where the repressor attaches (found at the end of the promoter and before the genes)
Regulatory Gene- DNA that codes for a protein (Such as a repressor) that controls the expression of other genes
Hox gene- A series of genes that control where tissues and organs develop in the various regions of an embryo (developmental
gene)
DNA structure: Consists of 2 strands- Double helix- Made up of nucleotides (building blocks)
Community- a collection of interacting populations that live in the same ecosystem (the living portion of an ecosystem)
Consumer- an organism in a community that is heterotrophic- 1st level consumer (Primary): herbivores (feed off of producers)- 2nd level
consumer (Secondary): carnivores- 3rd level consumers (Terery)-obtains 10% of the energy from each trophic level before it (3rd level consumer
contains least amount of energy)- also called Heterotrophs
Decomposer- an organism that breaks down dead organic material (Ex. Bacteria, fungi)- break down nutrients in dead organisms so matter can
cycle and be recycled by producers- organisms that feed on wastes and dead organic matter from all trophic levels (Ex. Bacteria, fungi)
Detritus- particles of dead organic matter- it includes the wastes and remains or organisms that are no longer alive- it is an important
component of some food webs
Ecological Pyramids (and examples)- A diagram that represents the relative amounts of energy or matter in each trophic level of a food web10% of energy from each trophic level is transferred- rest of energy is released as heat into atmosphere (Ex. Number pyramid, energy pyramid,
biomass pyramid)
Ecology- the study of organisms and how they interact with their environment
Ecosystem- consists of the living communities and the nonliving (abiotic) factors in an environment
Eutrophication- the process where bodies of water are overloaded with nutrients- it is often the result of human activities (Ex. Fertilizer runoff,
detergents, leaking sewage)- it can lead to rapid growth of algae in aquatic ecosystems that ultimately depletes the oxygen levels in the water
and reduces water quality
Food Chain- the pathway that the transfer of energy takes in an ecosystem (shows feeding sequence- involves producers, consumers,
scavengers, and decomposers)- feeding sequence in which organisms obtain energy- interrelated food chains are called a food niche- model of
the energy flow from one organism to another trophic level
Food Web- consists of all the interconnecting food chains in an ecosystem- producers make up the 1st trophic level
Herbivore- a consumer that eats only plants- eats producers- (Ex. Rabbit, cows)
Heterotroph- an organism that cannot make its own food- consumers- obtain energy and nutrients by devouring other organisms
Carbon Cycle- carbon held in fossil fuels, until human activities, such as burning fossil fuels, release it into the atmosphere- carbon is with
oxygen as carbon dioxide- Surface Ocean Route: got here by diffusing from atmosphere, decomposing marine life, or circulating water from
the deep ocean (chilly water absorbs carbon faster); Deep Ocean Route: gets CO2 from circulation with surface ocean and dead and decaying
marine life-holds over 65% carbon-stays in ocean for 100’s of years; Marine Life Route: photoplankton take carbon and use it for
photosynthesis-marine can’t survive without carbon-high levels of carbon are harmful to algae, mollusks, and corals; 30% increase in CO2 over
150 years )since Industrial Revolution); carbon is universal; carbon from the deep ocean moves from deep ocean to surface ocean and then to
atmosphere- Land Plants Route: plants use carbon for photosynthesis; they grow faster with more CO2; they release carbon back into
atmosphere after respiration; Soil Route: plants died so carbon is in soil as detritus (decomposing plants and animals); soil is made of inorganic
parts; stores 3% carbon; carbon sent to atmosphere after break down of detritus; Atmospheric Route: plants release carbon back into the
atmosphere
Nitrogen Cycle- the pathway by which nitrogen moves through the environment (includes nitrogen fixation, denitrifying, amnonification)Nitrogen Fixation changes nitrogen into amnonia (asobactor and lasogna are bacteria that help this change)- nitrification changes the amnonia
into nitrates, and then into nitrates (lightning can change nitrogen to nitrates- a lot of energy to make nitrogen gas into nitrates)- denitrification
takes nitrates and makes them into nitrogen gas
Nonrenewable resources: a resource that cannot be replenished as quickly as it is being consumed- Ex. fossil fuels
Omnivore- a consumer that eats both producers (Ex. Plants) and consumers (Ex. Other animals) (Ex. Humans, bears, crows)
Primary Productivity- the rate at which organic matter (biomass) is created by producers in an ecosystem
Producer- an autotroph that provides food for a community- receives energy from sun- first level in a food web
Trophic levels- a step in the transfer of energy (and matter) in a food chain- each trophic level receives only 10% of the energy from below it
Global warming:
Ozone layer and depletion:
Acid rain:
Gene: A section of DNA that codes for a protein (polypeptide)
Codon (including start and stop): Three sequential bases of mRNA (usually codes for an amino acid)- Start=AUG- Stop=UAA, UAG, UGA64 possibilities
-Group of 3 nucleotides in mRNA that specifies an amino acid
-Group that can be thought of as one of the words of the genetic message
-The sequence of 3 nitrogenous bases in mRNA
Anticodon: Three sequential bases on tRNA that is complementary to the codon
-The 3-base sequence found on tRNA that binds to a complementary piece of mRNA during protein synthesis
Genetic Code: DNA codes for all the different patterns in an organism- determined by the sequence of nitrogen bases/nucleotides
-Consists of 64 codons along with their corresponding amino acids
Intron: A section of DNA (or RNA) that does not code for a part of a protein
-Section of DNA or RNA that does not code for proteins
Exon: A section of DNA (or RNA) that codes for a part of a protein
-Section of DNA or RNA that codes for part of a protein
Expressed Gene: A gene that is being actively transcribed (the process of protein synthesis is taking place)
RNA Polymerase: Enzyme that directs transcription by matching RNA bases to complementary DNA base
-Enzyme that binds directly to a DNA molecule during transcription
Initiation and Elongation: Initiation begins with the building of mRNA to the small subunit of a ribosome. The first tRNA, with its amino acid
binds to the complementary part of mRNA. The large subunit of the ribosome binds to the small subunit so that the first tRNA is positioned in
the P site. The second tRNA enters and binds to the A site of a ribosome. The amino acid from the first tRNA detaches and forms a peptide
bond with the second amino acid at the A site. The first tRNA is released, the ribosome moves 3 bases along the mRNA, and a new tRNA
moves into the A site. The tRNA that had been in the A site moves into the P site.
-Elongation is the lengthening of the amino acid chain during protein synthesis
Compare structure of DNA to that of RNA:
1. The sugar in RNA is ribose instead of deoxyribose
2. RNA is generally single stranded, not double
3. RNA contains Uracil in place of Thymine
- RNA is also made from nucleotides
- Phosphate group
Understand process of transcription, RNA splicing, translation:
Transcription- process where information stored in DNA is transferred to mRNA (mRNA is made) (occurs in the nucleus)
- Process by which RNA is made
- Process by which part of the nucleotide sequence of a DNA molecule is copied into RNA
- The process of transferring information from DNA to a strand of RNA
RNA splicing (RNA editing)- Process where introns are removed from pre-mRNA and exons are joined together to form mRNA
Translation- (occurs at the ribosomes in the cytoplasm) Process where the code in mRNA is converted into an amino acid sequence
(building a protein)
-Process by which nucleotide in mRNA are decoded into a sequence of amino acids in a polypeptide
-Formation of an amino chain from the information provided by mRNA
Roles of:
mRNA- type of RNA that carries the instruction for protein production to the ribosome- messenger
-Serves as a template for the assembly of amino acids during protein synthesis
-Form of RNA that serves as a messenger from DNA to the rest of the cell
-RNA that carries the genetic instructions for protein production
tRNA- type of RNA that transports amino acids to the ribosome
-Form of RNA that transfers amino acids to the ribosome during the assembly of a protein
-RNA that carries amino acids to the ribosome during protein synthesis
rRNA- type of RNA that is a major component of the ribosome
-Form of RNA that is part of the structure of ribosomes
Parts of a ribosome (large, subunit, small subunit, P site, A site):
Large subunit- catalyzes the reactions that combine the amino acids into a polypeptide chain- 50S
Small subunit- Binds to a mRNA molecule and reads its genetic codes- 30S
P site- Donates the amino acid used to form the polypeptide chain
A site- The amino acid located here accepts the released amino acid from the P site. It also accepts the next tRNA from the cytoplasm
Autotroph- an organism that produces its own food (from inorganic compounds and sunlight)- also called a producer (Ex. Tree, shrubs, grass)beginning of food chain
Biodiversity- the number of different species in an ecosystem (variety of life)
Biological Magnification- buildup of a pollutant in organisms at higher trophic levels in a food chain- the increasing concentration of a
harmful, and usually toxic, substance as it moves up the food chain- the toxins tend to be stored in the fatty tissues of the animal (Ex. DDT was
400x more concentrated in top carnivores than in the producers. Other pollutants that tend to biomagnify include mercury, lead and PCB’s)
Speciation: The formation of a new species-formation of one of more new species from a single ancestral species- process by which a new
species is formed from an existing one
Divergent Evolution: (similar populations or species evolving in different environments)- Process in which once-related population evolve
independently (often because of geographic isolation)- 2 or more related species becoming more and more dissimilar- evolution in which
highly distinct species were once both similar to an ancestral species- the presence of homologus structures in different species is an indication
of divergent evolution- Ex. Polar bear and brown bear; red fox and kit fox
Convergent Evolution: (different populations or species evolving in similar environments)- Process by which unrelated organisms
independently evolve similarities- evolution of similar traits in distantly related organisms- Leads to production of analogous structures- Ex.
Wings of birds and butterflies; insect mimicry; streamlined shape of fish and small whales.
Gene Pool: The combined genetic material for all members of a population- (all the genes in a population)- all the genes in a populationcombined genetic makeup of all the members of a population
Genetic Drift (including founder effect and bottleneck effect): Random changes in the allele frequencies of a population due to chance
happenings (events)- This generally occurs in small populations (large populations tend to be able the withstand these event without significant
effect on their allele frequencies)- Unlike natural selection, an individual’s fitness generally does not have great influence on whether or not it
is removed from the gene pool during genetic drift (it is a non-selective event)- The small population is not representative of the larger “parent
population” (certain alleles may be lost, over-represented, or under-represented)- There are tends to be less genetic diversity- 2nd major
mechanism driving evolution- an independent process that produces random changes in the frequency of traits in a population- results from the
role that chance plays in whether a given trait will be passed on as individuals survive and reproduce- the change in allele frequencies of a
population as a result of chance processes- the chances of genetic drift in larger population are less- chance is involved in genetic
recombinations during crossing over in meiosis- random change in allele frequency due to chance events
Founder Effect: A small number of individuals from a large population migrate ad colonize a new habitat- Ex “Mutiny on the Bounty”
and Pitcairn Island; Darwin’s finches, and the Galapagos Islands
Bottleneck Effect: Occurs when catastrophic events (volcanic eruption, earthquake, fire, flood, over-hunting) decimate a population so
that only a small percentage of the population survives and are left to repopulate the community (or the world, in severe instances)- Ex.
Cheetahs and the ice age; Northern Elephant Seals and over-hunting
Hardy-Weinberg principle, equation, and factors: describes the specific conditions required for genetic equilibrium to remain unchanged in a
population (conditions necessary for no evolution)- The conditions are: no natural selection, no migration, no mutations, mating must be
random (no preferential selection of mates), and it must be a large population- p=frequency of the dominant allele(A); q=frequency of the
recessive allele(a); p+q=1- the property can also be used to predict the probability of genotypes: p^2=frequency of the homozygous dominant
genotypes (AA); 2pq=frequency of the heterozygous genotype (Aa); q^2=frequency of the homozygous recessive genotype (aa);
p^ 2+2pq+q^2=1
Coevolution: process in which 2 species evolve in response to changes in each other- a change in one species acts as a selective force on
another species- Ex. Flowers (shape, scent, or color) and their pollinators (feeding structures of insects, birds, bats; predators and prey
Cladistics: A taxonomic approach (group living things into categories) that classifies organisms according to the order in time that branches
arose in the evolutionary history of the taxa- used to group organisms into categories that represents lines of evolutionary descent, not just
physical similarities- work on the premise that related species share unique qualities that were not present in distant ancestors- ignores
characteristics that were present in the distant ancestor because they reveal nothing about the pattern of evolutionary branching that occurred
after that point in time
Isolating mechanisms: individuals of the same population interbreed and share a common gene pool- when 2 population of the same species
become reproductively isolated from each other, they cannot interbreed- these populations start to have separate gene pools and respond to
natural selection as separate units- reproducing isolationism can develop in a variety of ways- Behavioral Isolation: occurs when 2 populations
are capable of interbreeding, but have difference in behavior, such as courtship rituals; Ex. Eastern and Western meadowlarks use different
mating songs- Geographic Isolation: (allopatric speciation) occurs when 2 populations are separated by geographic barriers such as mountains,
oceans, or rivers; Ex. Subspecies Abert squirrel and Kaibab squirrel (separated by the Colorado River about 10,000 years ago)- Temporal
Isolation: occurs when 2 or more species reproduce at different times; Ex. 2 similar species of orchids all live in the same rainforest. Each
species only release pollen on a single day-because each species releases pollen on a different day, they cannot pollinate one another
Seed:
Fruit:
Transpiration:
Tracheid:
Sieve Cell:
Flower:
Sepal:
Petal:
Stamen and its parts (anther, filament):
Pistil and its parts (stigma, style, ovary):
Pollination:
Ovule:
Pollen Grain:
Embryo Sac:
Seed dormancy:
Seed Dispersal:
Process of double fertilization:
Characteristics of plants: eukaryotic (cells have a nucleus)- have cells walls consisting of cellulose- autotrophic (photosynthesize)multicellular- exhibit alternation of generations
Characteristics and examples of gymnosperms: “naked seeds”; bear their seeds directly on the surfaces of their cones- sporophyte is dominantthey have vascular tissue- male cones produce pollen- female cones produce ovules which will become seeds if they are fertilized- they are
wind-pollinated- Ex. Conifers-have needle like leaves, most are evergreens, includes pines, spruces, firs, cedars, redwoods; cycads-palm like
plants found in tropical and subtropical regions including Florida; gingkoes-only on species remains, considered a “living fossil” (doesn’t
appear to have evolved must over its long existence); gnethophytes-only 3 genera, one found in southwestern USA
Characteristics and examples of angiosperms:
Compare and contrast monocots and dicots:
Compare and contrast wind-pollinated flowers to insect-pollinated flowers:
Compare and contrast different types of chromosomal mutations and gene mutations: