Final Biology Exam

Mutations are the ultimate source of genetic variation. However, they usually occur at very low frequencies. Assume a mutation resulting in a novel allele occurs in a gene in one individual in a population of 500 diploid individuals. What is the frequency of the new allele? 0.01 0.001 0.05 0.005

0.001

If the frequency of allele A is 0.7 in a population that is in Hardy-Weinberg equilibrium, what would the frequency of the heterozygous Aa genotype be? 0.3 0.09 0.42 0.49

0.42

Purple spots is a homozygous recessive genetic trait in martians (assume their hereditary patterns match that of eukaryotes on earth). If 25 in 10,000 martian babies have spots, what are the expected frequencies of the dominant S and recessive s alleles in a population in Hardy-Weinberg equilibrium. S = 0.0005, s = 0.9995 S = 0.9500, s = 0.0500 S = 0.9605, s = 0.0395 S = 0.0005, s = 0.0025

0.9500, 0.0500

Imagine you are studying a population of plants and you have determined that they are all genetic clones of one another. You are interested in a particular gene found in the population that you have named LLT (low-light tolerance), that allows it to live in shady areas. What is the frequency of this allele in the population you study? 1 0.5 It is not possible to determine the allele frequency with the information provided. 0

1

Patients can develop antibiotic resistant M. tuberculosis bacterial infections. Researchers discovered that the strain of M. tuberculosis taken from a dead patient had a point mutation in the rpoB gene that codes for part of the RNA polymerase enzyme. This mutant form of RNA polymerase does not normally function as well as the more common form, but a commonly used antibiotic called rifampin does not affect the mutant rpoB. A researcher places M. tuberculosis isolated from the patient a year before death (no rpoB mutation) in cell cultures with M. tuberculosis isolated from the dead patient (with rpoB mutation). Half the cell cultures contain just standard nutrients, and the other cell cultures contain rifampin in addition to the standard nutrients. After many cell generations, the researcher finds that _____. (choose one) 1.) very few M. tuberculosis in the standard nutrient cell cultures carry the rpoB gene mutation, but almost all of the M. tuberculosis in the cell cultures with rifampin carry the rpoB mutation 2.) a mix of both M. tuberculosis strains thrive in the standard cell cultures, but no living bacteria can be found in the cell cultures that contain rifampin 3.) very few M. tuberculosis in any of the cell cultures carry the rpoB gene mutation 4.) almost all of the M. tuberculosis in both types of cell cultures carry the rpoB mutation 5.) almost all M. tuberculosis in the standard nutrient cell cultures carry the rpoB gene mutation, but very few of the M. tuberculosis in the cell cultures with rifampin carry the rpoB mutation

1

If the allele frequency for the recessive single allele that causes a particular rare hair color is 0.02, how frequently would you expect the hair color to be present in humans? 1 in every 5000 individuals 1 in every 2000 individuals 1 in every 50 individuals 1 in every 2500 individuals

1 in every 2500 individuals

Interphase

1.) chromosomes replicate 2.) centrosomes replicate 3.) DNA is decondensed

Hardy-Weinberg Equilibrium Conditions

1.) there is no difference in the survival and reproductive success of individuals 2.) the population is sufficiently large to prevent sampling errors 3.) Populations are not added to or subtracted from by migration 4.) there is no mutation 5.) individuals mate at random

In another study of Locus II in a new population, you find the following genotype data: 20 SS10 FS10 FF What are the expected Hardy-Weinberg genotype frequencies? 9/64 SS; 30/64 FS; 25/64 FF 25/64 SS; 15/64 FS; 9/64 FF 25/64 SS; 30/64 FS; 9/64 FF 9/64 SS; 15/64 FS; 25/64 FF 25/64 SS; 9/64 FS; 25/64 FF

25/64 SS; 30/64 FS; 9/64 FF

If there are 100 individuals in a population and 20 are homozygous for B, 60 are heterozygous, and 20 are homozygous for b, what is the allele frequency of B? 60% The frequency of B can't be calculated with the provided information. 20% 40% 50%

50%

Recall that in Mendel's garden peas, the yellow gene determines flower color, with the A (yellow) allele dominant to the a (green) allele. In a population of 200 plants, the genotype frequencies are 50% AA, 25% Aa, and 25% aa. What are the allele frequencies? 50% A, 25% a 62.5% A, 37.5% a 50% A, 50% a 87.5% A, 12.5% a 75% A, 25% a

62.5%A 37.5%a

In a population of Mendel's garden peas, the frequency of the dominant A (yellow flower) allele is 80%. Let p represent the frequency of the A allele and q represent the frequency of the a allele. Assuming that the population is in Hardy-Weinberg equilibrium, what are the genotype frequencies? 80% AA, 10% Aa, 10% aa 16% AA, 40% Aa, 44% aa 64% AA, 32% Aa, 4% aa 50% AA, 25% Aa, 25% aa 75% AA, 15% Aa, 10% aa

64%AA 32%Aa 4%aa

In a population of mice, the frequency of the dominant A (brown coat) allele is 90%. Let p represent the frequency of the A allele and q represent the frequency of the a allele. Assuming that the population is in Hardy-Weinberg equilibrium, what are the genotype frequencies? 50% AA, 25% Aa, 25% aa 80% AA, 10% Aa, 10% aa 90% AA, 5% Aa, 5% aa 81% AA, 18% Aa, 1% aa

81%AA 18%Aa 1%aa

In a population of Mendel's garden peas, the frequency of green-flowered plants (genotype aa) is 49%. The population is in Hardy-Weinberg equilibrium. What are the frequencies of the AA and Aa genotypes? 42% AA, 9% Aa 33% AA, 18% Aa 9% AA, 42% Aa 49% AA, 2% Aa

9% AA, 42% Aa

You are given the following information about a population: • There are two alleles: C and c. • C codes for green hair and c codes for white hair. • C is dominant over c. • The frequency of the c allele is 0.3. • The population is comprised of 100 individuals. Assuming the population is in Hardy-Weinberg equilibrium, how many individuals have green hair? 91% of the population will have green hair 51% of the population will have green hair. 81% of the population will have green hair. 9% of the population will have green hair. 49% of the population will have green hair.

91% of the population will have green hair

Phosphate Group

A chemical group consisting of a phosphorus atom bonded to four oxygen atoms

Nucleotides

A constituent of nucleic acids consisting of a 5-carbon, a nitrogen-containing base, and one or more phosphate groups

Microfilaments

A helical polymer of actin monomers present in various locations in the cytoplasm, that helps make up the cytoskeleton

In which of the following situations is genetic drift likely to occur? A river changes course, changing the local environment for a population of butterflies. A small population of lizards is isolated on a small island. Two schools of tuna merge together to form one large population. A mouse develops a fur coat that enables it to hide more readily from predators.

A small population of lizards is isolated on a small island.

Hardy-Weinberg Equilibrium

A state in which allele and genotype frequencies do not change over time, implying the absence of evolutionary forces

Primary Active Transport

Active transport that uses the energy of ATP directly

Secondary Active Transport

Active transport that uses the energy of an electrochemical gradient to drive the movement of molecules

Allele frequency can be measured using what technique? DNA sequencing gel electrophoresis All of these choices are correct. observation of phenotype

All

Which of the answer choices reflects a difference in fitness among individuals in a population? All individuals in the population have the same number of offspring. Males in the population all sire equal numbers of offspring. Males in the population have large horns on their heads. All offspring born in the population come from 25 percent of the females in the population.

All offspring born in the population come from 25 percent of the females in the population.

The gene pool is All the genes present in the species on earth All the genes present in the individuals in the population All the alleles present in the individuals in the population All the alleles present in the species on earth

All the alleles present in the individuals in the population

What is the primary difference between natural selection and artificial selection? Natural selection results in evolution; artificial selection does not. Artificial selection relies on traits that allow for greater reproductive success. Artificial selection is driven by humans. Natural selection may select traits that are detrimental.

Artificial selection is driven by humans

What is the primary difference between natural selection and artificial selection? Artificial selection relies on traits that allow for greater reproductive success. Natural selection results in evolution; artificial selection does not. Artificial selection is driven by humans. Natural selection is controlled. Natural selection may select traits that are detrimental.

Artificial selection is driven by humans.

If a population is NOT in Hardy-Weinberg equilibrium for a specific gene, which of the following can be said with certainty? Individuals with one form of the gene have greater mating success Selection is acting on this gene At least one mechanism that alters allele frequencies is acting on this gene New forms of the gene have entered the population due to immigration

At least one mechanism that alters allele frequencies is acting on this gene

What is one reason why many mutations may be deleterious? Most mutations are actually beneficial, not deleterious. Because the body has no way to detect or correct mutations. Any change in the DNA sequence means that DNA no longer functions properly. Because the genetic code has redundancy built in. Because if a mutation changes the primary structure of a protein, the protein may no longer work.

Because if a mutation changes the primary structure of a protein, the protein may no longer work.

How is biological fitness measured? Biological fitness measures the longevity of an individual Biological fitness measures the number of offspring produced in a population Biological fitness measures the overall health of an individual Biological fitness measures the relative reproductive success of an individual relative to others in the population

Biological fitness measures the relative reproductive success of an individual relative to others in the population

Which aspect of Galapagos finches is the best example of heritable variation? Body size varies among individuals and large parents tend to have large offspring. The annual rainfall in the finch habitat is subject to wide variation Body size varies among individuals and large parents are equally likely to have large or small offspring. Body size is controlled by genes, which are passed from parents to offspring.

Body size varies among individuals and large parents tend to have large offspring.

Which of these conditions are NOT true of populations evolving due to natural selection? Condition 1: Individuals in a population vary in traits that are heritable. Condition 2: Some heritable traits increase reproductive success. Condition 3: Individuals pass on all traits they acquire during their lifetime. condition 1 only condition 3 only condition 2 only conditions 1, 2, & 3 conditions 2 & 3

Condition 3 only

Replication of DNA to Protein

DNA Transcription RNA Translation Protein

A certain species of aquatic insect exists as either a cream color or a dark brown color. If predators (fish) that can see and catch intermediate colored insects increase in frequency, then the insect would be under _____ selection. stabilizing directional artificial disruptive

Disruptive

In a study of the alcohol dehydrogenase (ADH) enzyme in a population of Drosophila melanogaster, a researcher finds the following allele frequencies for the Fast (F) and Slow (S) alleles of the gene. FF FS SS 0.81 0.18 0.01 Now a toxin is released into the environment that kills off all FF genotype flies in the population. What are the new allele frequencies after this selection event? F = 0.9, S= 0.1 F = 0.5, S = 0.5 F = 0.18, S = 0.1 F = 0.474, S = 0.526

F = 0.474, S = 0.526

In a study of the alcohol dehydrogenase (ADH) enzyme in a population of Drosophila melanogaster, a researcher finds the following allele frequencies for the Fast (F) and Slow (S) alleles of the gene. FF FS SS 0.81 0.18 0.01 What are the allele frequencies of F and S? F = 0.81, S = 0.19 F = 0.09, S= 0.91 F = 0.5, S = 0.5 F = 0.9, S= 0.1

F = 0.9, S= 0.1

Like natural selection, genetic drift always leads to adaptations within populations; only mutations do not result in adaptations. True False

False

How do fossils provide evidence of evolutionary history? Fossils provide a record of extinct species. Fossils provide an accurate account of the number of species that exist at any particular time. Older fossils are an excellent source of DNA from which we can construct molecular phylogenies. Fossils provide complete information on extinct species.

Fossils provide a record of extinct species.

Which of the answer choices is not a condition of the Hardy-Weinberg equilibrium? Individuals can migrate in and out of a population as long as the population size remains constant. Mating within a population must be random. Individuals of any genotype must have the same reproductive success as individuals of any other genotype. The size of a population must be large.

Individuals can migrate in and out of a population as long as the population size remains constant.

In part (a) of the figure, the original population consists of 9 A1A1, 11 A1A2, and 7 A2A2 individuals. How does the frequency of the A1 allele compare between the original and new populations? t is 0.333 in the original and 0.667 in the new population. It is the same in both populations It is 0.537 in the original and 0.834 in the new population. It is 0.834 in the original and 0.537 in the new population

It is 0.537 in the original and 0.834 in the new population.

In 1986 a nuclear power accident in Chernobyl, USSR (now Ukraine), led to high radiation levels for miles surrounding the plant. The high levels of radiation caused elevated mutation rates in the surviving organisms, and evolutionary biologists have been studying rodent populations in the Chernobyl area ever since. Based on your understanding of evolutionary mechanisms, which of the following most likely occurred in the rodent populations following the accident? Mutation led to increased genetic variation. Mutation caused genetic drift and decreased fitness. Mutations caused major changes in rodent physiology over time. Mutation caused fixation of new alleles.

Mutation led to increased genetic variation.

Balancing Selection

Natural selection that acts to maintain two or more alleles of a given gene in a population

Which of the following statements is FALSE of the fossil record? None of the answers are false. Fossils can be found of extinct animals. Transitional forms of fossils show relatedness between species. Carbon and other radioactive dating can show that fossils are very old.

None of the answers are false.

Why is the fossil record NOT a complete catalog of biological history? The process of fossilization often destroys anatomical features of the organisms being preserved. Only animals, not plants, are fossilized Not all organisms fossilize with equal probability. Fossilization destroys the structure of DNA.

Not all organisms fossilize with equal probability

An insecticide is being used to control the mosquito population in northern Minnesota. It worked well for several years but in the last year, the population of mosquitoes is spiking again. Which of the following explanations best describes what may be happening? The insecticide formula was changed and is of poor quality. Natural selection caused a mutation and change in the the mosquito Only insecticide resistant mosquitos survived and reproduced so each year more mosquitos were insecticide resistant Gene drift has occurred leading to resistant mosquitos

Only insecticide resistant mosquitos survived and reproduced so each year more mosquitos were insecticide resistant

Hammer-head bats are a species of African fruit bat. During the breeding season, males gather in mating arenas, where they display to females who pass through and assess males before selecting individuals with which to mate. This is an example of: sexual selection. stabilizing selection. disruptive selection natural selection.

Sexual Selection

Translation

Synthesis of a polypeptide chain corresponding to the coding sequence present in a molecule of messenger RNA

Permeability

Temperature(warm=up cold=down) Length of trail(long=down short=up) Saturated=down unsaturated=up

Active Transport

The "uphill" movement of substances against a concentration gradient requiring an input of energy

Which of the following "counts" as an example of biological evolution? A person moves to a hot location and grows accustomed to the heat People living in modern clean environments develop less infectious diseases A caterpillar forms a cocoon and a butterfly emerges The human population living in northern latitudes developed lighter skin over many generations

The human population living in northern latitudes developed lighter skin over many generations

Proteins

The key structural and functional molecules that do the work of the cell, providing structural support and catalyzing chemical reactions

S Phase

The phase of interphase in which the entire DNA content of the nucleus is replicated

M phase

The stage of the cell cycle consisting of mitosis and cytokinesis in which the parent cell divides into two daughter cells

Secondary Structures

The structure formed by interactions between stretches of amino acid in a protein

Quaternary Structure

The structure that results from the interactions of several polypeptide chains (all bonds are held together to create proteins)

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would happen in environments that lack antibiotics? These bacteria would try to make the cost worthwhile by locating and migrating to microenvironments where traces of antibiotics are present. These bacteria would be outcompeted and the allele frequency for the antibiotic resistance would decrease in the population. These alleles would be maintained in case the antibiotics appear. The number of alleles conveying antibiotic resistance would increase in these bacteria.

These bacteria would be outcompeted and the allele frequency for the antibiotic resistance would decrease in the population.

Fossils found in rock deposits are evidence that species change through time. True False

True

One key principle of natural selection is that there is competition for resources True False

True

At the genetic level, evolution is: a change in the frequency of an allele or genotype over time. an increase in fitness over time. a change in fitness over time. a population change over time.

a change in the frequency of an allele or genotype over time.

Centrosomes

a compact structure that is the microtubule organizing center for animal cells

Ribosomes

a complex structure of RNA and protein, bond to the cytosolic face of the RER in the cytoplasm, on which proteins are synthesized

Artificial Selection

a form of directional selection similar to natural selection, done intentionally by humans

Sexual Selection

a form of selection that promotes traits that increase an individual's access to reproductive opportunities

Directional Selection

a form of selection that results in a shift of the mean value of a trait in a population over time

Stabilizing Selection

a form of selection that selects against extremes and therefore maintains that status quo.

Species

a group of individuals that can exchange genetic material through interbreeding to produce fertile offspring.

Microtubules

a hollow, tubelike polymer of tubulin dimers that helps make up the cytoskeleton

Actin

a protein that forms microfilaments; it associates with the motor proteins myosin in muscles to contract and generate force

Genetic Drift

a random change in the frequency of an allele due to the statistical effects of finite population size

Founder Event

a type of genetic drift that occurs when only a few individuals establish a new population

Gene pool

all the alleles present in all individuals in a population or species

Populations

all the individuals of a given species that live and reproduce in a particular place

The Hardy-Weinberg equation can be used to predict genotype frequencies from ______ frequencies. phenotype advantageous mutation allele deleterious mutation chromosome

allele

Bottleneck

an extreme, usually temporary, reduction in population size that may result in marked loss of genetic diversity and in the process, genetic drift

In contrast to positive and negative selection, _____ selection acts to maintain two or more alleles in a population. disruptive balancing directional stabilizing

balancing

Currently the only predators of Galápagos marine iguanas are Galápagos hawks. Iguana body size is not correlated with risk of hawk predation, although small iguanas can sprint faster than large iguanas. If predators (e.g., cats) that preferably catch and eat slower iguanas are introduced to the island, iguana body size is likely to __________ in the absence of other factors. The iguanas would then be under _________ selection. decrease, disruptive decrease, directional increase, directional increase, stabilizing increase disruptive

decrease, directional

Exergonic

describes reactions with a negative delta G that release energy and proceed spontaneously

Endergonic

describes reactions with a positive delta G that are not spontaneous and so require an input of energy

Migration reduces genetic differences between populations by allowing gene _____ between the two. flow deletion repression drift

flow

All the alleles present in all the individuals in the species refers to ____. gene pool grouping population species

gene pool

Nonrandom Mating

mate selection biased by genotype or relatedness

You have spent time working with a population of beetles. Males range in size from 2-6 cm in length. You realize that the females only mate with males that measure less than 3 cm long. If you measured allele frequencies at a single locus that contributes to overall length, would you expect this population to be in Hardy-Weinberg equilibrium from one generation to the next? no yes

no

Disruptive Selection

operates in favor of extremes and against intermediate forms

Genetic drift has an especially significant effect in what kind of populations? populations that are in Hardy-Weinberg equilibrium populations that are large populations that are small populations that are migrating

populations that are small

Which of the answer choices is an example of stabilizing selection? decrease in the number of birds with intermediate-sized beaks who are unable to eat large or small seeds antibiotic resistance in bacteria breeding dogs from wolves selection for average birth weight in humans

selection for average birth weight in humans

Competition among members of one sex for access to the other sex is called _____ selection. disruptive disexual stabilizing sexual directional

sexual

All the individuals that can exchange genetic material through interbreeding are referred to as a ____. grouping species gene pool population

species

In a phylogenetic tree, a node or branching point represents: the common ancestor from which the descendent species diverged. the ancestral species from which all species in the phylogeny arose. the species in the fossil record from which the descendent species diverged one of the descendent species in the phylogeny.

the common ancestor from which the descendent species diverged.

5'end

the end of a nucleic acid strand containing a free 5'phospate group

3'end

the end of a nucleic acid strand that carries a free 3'hydroxyl

Gene Flow

the movement of alleles from one population to another through interbreeding between members of each population

Migration

the movement of organisms from one place to another, including the movement of individuals from one population to another

Tertiary Structure

the overall 3D shape of a protein formed by interaction between secondary structures

Calvin Cycle

the process in which CO2 is reduced to synthesize carbs with ATP and NADPH as the energy source

Allele frequencies

the proportion of a specified allele among all the alleles of a gene in a population

Selection

the retention or elimination of mutations in a population of organisms

Primary Structure

the sequence of amino acids in a proteins

Transcription

the synthesis of RNA from a DNA template

Gene

the unit of heredity; the stretch of DNA that affects one or more traits in an organism usually through an encoded protein or noncoding RNA

The allele frequency of all the alleles of a gene present in the population must add up to 1 True False

true