bio 152 exam 1 - quizzes
Flower color in sweet pea in part comes from the pigment anthocyanin. One step is catalyzed by an enzyme called chalcone synthase. When chalcone synthase doesn't work at all , the flowers are white. The normal enzyme is denoted + whereas the non-functioning enzyme is denoted -. Heterozygotes are purple. In a particular large population the following genotype frequencies are observed: genotype frequencies ++0.60 +-0.20 --0.20 What is the frequency of the - allele in this population?
0.30
Flower color in sweet pea in part comes from the pigment anthocyanin. One step is catalyzed by an enzyme called chalcone synthase. When chalcone synthase doesn't work at all , the flowers are white. The normal enzyme is denoted + whereas the non-functioning enzyme is denoted -. Heterozygotes are purple. In a particular large population the following genotype frequencies are observed: genotype frequencies Genotype Frequency ++0.60 +-0.20 --0.20 What is theexpectedheterozygote frequency ?
0.42
In a population of butterflies has the following gene frequencies: 40% AA, 10% Aa, and 50% aa. What is the frequency of the a allele?
0.55
The table below compares the heterozygosity of single nucleotide poymorphisms in the wolf genome from different populations in the US. Evaluate the statements below using these data: 1. True or False: The WY wolf (the highest heterozygosity of 0.276) has the most genes 2. Which of the following groups has the largest gene pool based on these data? 3. True or False: The NM wolf (with the lowest heterozygosity of 0.172) has gone through more natural selection than the other wolves
1. False 2. MT wolf 3. False
Evaluate each of the following as examples of acclimatization, adaptation or neither. 1. Lamprey are anadromous fish, they live as adults in salt water, but migrate to freshwater rivers and streams to breed (including our very own Connecticut river). To do this they have to change the ion concentration of their cells and blood. ___________ 2. White tailed deer fawns have a speckled coat which makes them hard to see in the early spring forests. As they age their coat becomes more uniform. This happens in all white-tailed deer during the first year of their life regardless of the conditions they live in. ___________
1. acclimitization 2. adaptation
The graph below shows the growth of two distinct strains of e. coli (A top and B bottom) for 40 hours in a liquid medium devoid of all carbon sources except glycerol (a carbon source e. coli don't usually eat). The difference between the strains is that Strain A had been cultured in a glycerol medium for thousands of generations. Based on these data evaluate the following statements. Strain A has _____ to the glycerol based medium if you leave B in this medium it will edit its genome in order to use the glycerol ____T or F
1. adapted 2. false
Describe as a difference in a gene or a difference in allele: 1. Tabby cats get their color from producing a pigment called melanin. Albino cats don't make melanin because there is a mutation in the code for an enzyme that makes melanin________ 2. Humans don't make vitamin C but most primates do. This is because most apes lost a portion of one chromosome that contained the code for the enzyme that makes vitamin C ________
1. allele difference 2. gene difference
1. True or false: Genetic drift is a form of natural selection that leads to adaptive change in a population 2. True or False: Assume there are two alleles in a population. If one increases in frequency, the other must decrease.
1. false 2. true
The selection occurs at the level of the _____1_____, since it is driven by ____2____ differences in individuals. However evolution occurs at the level of the_____3_____.
1. individual 2. phenotype 2. population
Natural selection acts on the _____1_____ of an organism. However, the differences in phenotype exist becomes of different ___2____. . Which alleles are present in a particular organism is called the organism's __3_____
1. phenotype 2. alleles 3. genotype
The raw material for evolution is created by____1___ mutations. Natural selection is a ______2 _____ process that acts upton the subsequent phenotypes to result in evolution.
1. random 2. non-random
Genetic drift and natural selection are both mechanisms of evolution, but they differ significantly. In genetic drift the changes in allele frequencies are ____1____. . They lead to changes in the population that are ___2____. . In natural selection the selection is __3___ and leads to _____4_____ change in the population.
1. random 2. not-necessarily adaptive 3. adaptive 4. non-random
The raw material for evolution is created by ___1____ mutations. Natural selection is a _____2_____process that acts upon the subsequent phenotypes to result in evolution.
1. random 2. non- random
Consider the trait for the siamese coat color pattern in cats. It is caused by a temperature sensitive mutant allele of the gene for tyrosinase (an enzyme that produces a dark pigment). If a cat that is a carrier for this allele (it's heterozygous for that gene with both the recessive allele and the dominant normal tyrosinase). What is that chance that any given gamete from that cat (a sperm or egg cell) will carry the mutant allele?
50%
Choose weather this example is acclimating or adapting to an environment: If you move from a cold to a hot climate, the salt content of your sweat will eventually go down.
Acclimitization
Choose weather this example is acclimating or adapting to an environment: Training at high altitude increases the hemoglobin in a cyclist's blood
Acclimitization
Choose weather this example is acclimating or adapting to an environment: A rare allele of a gene called EPAS1 helps people thrive at low oxygen concentrations whereas the more common allele is not as helpful. Most Tibetans have the rare allele whereas their close (at least genetically) relatives the Han Chinese usually have the common allele. In the Tibetans this is an example of.
Adaptation
Choose weather this example is acclimating or adapting to an environment: The big ears of the long eared jerboa help it radiate heat in the desert
Adaptation
Helianthus annuus and Helianthus petiolaris both share a common ancestor and live with overlapping territories. Both are well suited to their environment and are flourishing. A hybrid, Helianthus anomalus exists. It cannot interbreed with the parental species, but is well adapted to slightly drier spots (still in the same general geographical area). Which of the following concepts describes this situation? a) A hybrid zone showing reinforcement B) A hybrid zone showing stability c) Bottleneck effect d) Founder effect e) Adaptive radiation
B) A hybrid zone showing stability
what isolating mechanism? The differences in these mating rituals prevents mating between the wrong birds of paradise.Really worth watchinghttps://www.youtube.com/watch?v=L54bxmZy_NE
Behavioral isolation
True or False In the c. coli long-term evolution experiment, the mutation allowing the e. coli to metabolize citrate occurred in order to help the e. coli grow on citrate. That is, if the e. coli were growing in some other condition, the mutation definitely would not have happened.
False
True or False: In general dominant traits should increase overtime in a population.
False
I showed you the graph below in class. It compares the frequency of single nucleotide polymorphisms in alleles in Han Chinese and Tibetans, two populations who diverged ~3000 years ago. 1. True or False: Negative selection against the circle 2 polymorphism in the Tibetan population is the only explanation for why the it's different in the two populations. 2. True or False: The circle 1 polymorphism is not present in the Tibetan population. 3. True or False: A possible explanation for circle 3's presence in the Tibetan population is positive selection.
False False True
In class we looked at the data below. It represents the relative reproductive success of trout in the wild who had either wild parents (WXW), one wild and one captive bred parent (WXC), or two captive bred parents (CXC). Evaluate each of the following statements. True or False: The WXC fish probably have a higher allelic variability than the Wild fish (WXW). True or False: Gene flow between the two populations is leading to lower fitness for the population in general.
False True
what isolating mechanism? Lions and tigers can mate to produce Ligers or Tigons (depending on which is the mom), but the offspring are only infrequently able to have offspring of their own.
Hybrid sterility
What distinguishes natural selection from artificial selection
Natural selection primarily selects organism that will live longer.
In terms of evolution by natural selection, why does an individual's survival matter?
Surviving longer means that more opportunities to reproduce and therefore contribute more copies of that individuals genes to subsequent generations.
What isolating mechanism? The eastern spotted skunk and the western spotted skunk have overlapping geographic ranges but the eastern mates in the summer and the western mates in winter. Therefore there is no gene flow between the species.
Temporal isolation
True or False: In a population with two alleles for a given gene. If the frequency of one allele is p and the frequency of the other allele is q then p+q=1.
True
True or False: If a population is in HW equilibrium at a particular gene locus, then allele frequencies at that gene locus should not change from generation to generation unless perturbed by an outside force.
True
true or false: Genetic drift can lead to evolution in a population.
True
Evaluate the following statements with regards to evolution by natural selection: True or False: A population must have heritable variation in traits, some of which lead to more reproductive success. True or False:Asexual species are subject to evolution but not natural selection because they cannot have differential reproductive success True or False:A change in the environment will lead to more phenotypic variation in a species; this variability then allows for natural selection to take place.
True False False
The graph below shows the growth of four distinct strains of e. coli (labeled A, B, C, or D) for 40 hours in a liquid medium. Based on these data which of the following are true? a) A is better adapted to growing in the medium than D is. b) Culture D takes the longest to begin growing c) Culture D intentionally develops a mutation and begins growing d) Strain B is better acclimated to the medium than strain D.
a) A is better adapted to growing in the medium than D is. b) Culture D takes the longest to begin growing
Select the statement that is correct regarding the studies of the Galapagos finches as presented in this article. a) Bill dimensions must be a heritable trait (parents with larger bills will have offspring with larger bills). b) The changes in the bill size in Galapagos finches is an example of artificial selection not natural selection because the Grants identified the birds who could breed. c) The changes in bill dimensions observed in the Galapagos finches shows the natural selection acts on the population as a whole not on individuals. d) All of the data concerning the Galapagos finches are dependent on the weather changes caused by climate change. e) The finches that hatched in 1978 after the severe drought in 1977 grew smaller beaks in order to make it possible to eat the smaller seeds.
a) Bill dimensions must be a heritable trait (parents with larger bills will have offspring with larger bills).
Which of the following is a true with respect to genetic variation? a) It must be present in a population before natural selection can act upon the population. b) It tends to be reduced by meiosis. c) It arises in response to environmental change. d) Genetic variation is created by natural selection.
a) It must be present in a population before natural selection can act upon the population.
What are the assumptions that must be true for Hardy Weinberg equilibrium to exist at a particular gene locus? a) Population size is infinite. b) Niether mutation nor migration is introducting new alleles at this particular locus c) Random mating d) Natural selection is not acting on this particular gene locus. e) P2 + 2pq + q2 =1
a) Population size is infinite. b) Niether mutation nor migration is introducting new alleles at this particular locus c) Random mating d) Natural selection is not acting on this particular gene locus.
Which best describes genetic drift a) Through random chance some alleles decrease or increase in the population. b) The movement of alleles into a population through migration and inter-breeding c) Very large populations are likely to have more genetic diversity, but these allele frequencies will change up and down over time -- thus drifting. d) Alleles present at very low levels in the population are likely to disappear e) Over time mutations will build up in genes -- thus their sequence drifts.
a) Through random chance some alleles decrease or increase in the population.
A drawback of the BSC is that it cannot be applied to: a) asexual organisms like bacteria b) extinct organisms like dinosaurs c) none of these are drawbacks d) plants e) polymorphic species (like ants)
a) asexual organisms like bacteria b) extinct organisms like dinosaurs
When you use a field guide to identify a species by its appearance, you are applying the a) morphospecies concept b) Biological species concept c) Evolutionary species concept d) ecological species concept
a) morphospecies concept
In a population with two alleles for a given gene. If the frequency of one allele is p and the frequency of the other allele is q then p+q=1. a) true b) false
a) true
In any given population there will be variants of most genes. These occur at the same location on the chromosome but have at least a few different nucleotides. These are called (one word please and why not make sure you spell it right just because a computer is checking this):
alleles
The average percentage of genes in a population in which individuals have different alleles
average heterozygosity
An isolated population of Musk Weasels (the absolute weasliest of weasels) has a gene that codes for an enzyme which produces a smelly oily substance that makes musk weasels unpleasant to be around and unappetizing to most predators. One of the alleles codes for an enzyme that makes a truly horrific smell (H), the other has a slightly different sequence that is just vomit inducing (V). In the heterozygous state it is in between the two. What ways could more variability be introduced into this population at this particular locus? a) A musk weasel eating bird finds the horrific smell quite appetizing and so preferentially eats HH musk weasels. b) A drought that allows another population of musk weasels with a third allele to start interbreeding with this population c) Crossing over during meiosis that swaps parts of the V and the H alleles d) A mutation in the enzyme's gene such that it is no longer functional at all.
b) A drought that allows another population of musk weasels with a third allele to start interbreeding with this population c) Crossing over during meiosis that swaps parts of the V and the H alleles d) A mutation in the enzyme's gene such that it is no longer functional at all.
Which of the following is true with respect to genetic variation? a) It arises in response to environmental change. b) It must be present in a population before natural selection can act upon the population. c) It tends to be reduced by meiosis. d) Genetic variation is created by natural selection.
b) It must be present in a population before natural selection can act upon the population.
In humans, hair straightness or curliness is thought to be governed by a single pair of alleles showing partial dominance. Individuals with straight hair are homozygous for the S allele, while those with curly hair are homozygous for the c allele. Individuals with wavy hair are heterozygous (Sc). In a population: 25% were found to have straight (SS) hair, 35% had wavy hair (SC) 40% had curly hair (CC), Is this population in hardy Weinberg equilibrium? a) Yes observed matches predicted b) No, the observed heterozygote frequency is < that the predicted c) No, the observed heterozygote frequency is > that the predicted d) Yes because p2+2pq+q2=1 e) No because p2+2pq+q2=does not =1
b) No, the observed heterozygote frequency is < that the predicted
With regards to the mouse whisker breeding program outlined above which of the following are true? a) Reproductive success is not important in this case because you are choosing who mates. b) To be successful the whisker length must be heritable c) The whisker breeding program is not an example of artificial selection because the mice are still breeding naturally. d) To be successful whisker length must be governed by a single gene
b) To be successful the whisker length must be heritable
You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use? a) ecological b) morphological c) biological d) evolutionary
b) morphological
Natural events, such as an earthquake disaster that kills—at random—a large portion of the population, can magnify genetic drift.
bottleneck effect
Mouse whisker fanciers enjoy raising pet mice but they are very fussy about the whisker length. They like the whiskers to be as close as possible to 2.5 cm long, a very fine whisker length indeed. You wish to raise mice to take advantage of the mouse fanciers' shallow desires and deep pockets. You know nothing of mouse whisker genetics. You begin with a breeding population of several thousand mice with a whisker distribution as shown below: What should your breeding program be like? a) Choose mice from III only to breed so as to raise the average whisker length. b) Breed mice from I and III so that you get heterozygous mice. c) Choose mice in section II only and breed them to try to stabilize the whisker length around 2.5 cm. d) Select mice from II and III to breed so as to raise the average whisker length.
c) Choose mice in section II only and breed them to try to stabilize the whisker length around 2.5 cm.
What was Darwin's main contribution as outlined in the article. a) He was the first to describe artificial selection. b) He invented evolution. c) He proposed that natural selection was the mechanism of evolutionary change. d) He proposed that artificial and natural selection differed only in that artificial selection couldn't lead to a new species. e) He proposed evolution as the means of natural selection.
c) He proposed that natural selection was the mechanism of evolutionary change.
What does it mean that Hardy Weinberg equilibrium is a "neutral equilibrium" a) It means that if the allele frequencies change for some reason in one generation they will come back to the SAME allele frequency in the next generation. b) It means that allele frequencies can vary a bit as long as p+q=1 c) It means that if the allele frequencies change for some reason in one generation they will reach a NEW equilibrium level after just one generation of random mating d) It means that if you add up all the genotype frequencies they will equal 1 (i.e. p2 + 2pq + q2 =1 e) It means that allele frequencies can vary but genotype frequencies cannot.
c) It means that if the allele frequencies change for some reason in one generation they will reach a NEW equilibrium level after just one generation of random mating
Two closely related populations of mice have been separated for many generations by a river. Climatic change causes the river to dry up, thereby bringing the mice populations back into contact in a zone of overlap. Which of the following is not a possible outcome when they meet? a) They remain separate in the extremes of their ranges but develop a persistent hybrid zone in the area of overlap. b) They interbreed freely and produce fertile hybrid offspring. c) They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations. d) They no longer attempt to interbreed. e) They interbreed in the region of overlap, but produce sterile offspring.
c) They interbreed in the region of overlap, producing an inferior hybrid. Subsequent interbreeding between inferior hybrids produces progressively superior hybrids over several generations.
It is thought that polar bears originated from a population of brown bears (grizzlies) that became geographically isolated during a glaciation event that occurred about 150,000 years ago. This is an example of: a) adaptive radiation b) sympatric speciation c) allopatric speciation d) peripatric speciation
c) allopatric speciation
______is the process in which two groups of organisms living the same habitat diverge into separate species a) adaptive radiation b) perpatric speciation c) sympatric speciaiton d) co-speciation e) adaptive radiation
c) sympatric speciaiton
If a population conforms to Hardy Weinberg equilibrium then: a) The population is not experiencing evolutionary change for any genes b) There has to be a dominant allele and a recessive allele c)There is no migration into or out of the population altering the frequency of that allele. d) Natural selection is not acting on the gene in question e) Mutation is not introducing new alleles to the population for that gene
c)There is no migration into or out of the population altering the frequency of that allele. d) Natural selection is not acting on the gene in question e) Mutation is not introducing new alleles to the population for that gene
If a population is in hardy weinberg equilibrium at a particular genetic locus then genetic drift
cannot be occuring
The figure below compares the frequency of 4500 single nucleotide variants in the genomes of three populations inhabitants of Beijing, China (CEB), Shanghai, China, and Tokyo, Japan (JPT). (Hu et al Biomed central 2009). Which of the following statements are correct with regard to these two charts a) The B allele is probably dominant to the C allele because it has a higher frequency in the JPT popualtion b) If the frequency of the C allele was a bit above 0.3 in the last common ancestor of the Tokyo and Shanghai population then it could have been subjected to positive selection in the JPT population. c) If the frequency of the C allele was a bit above 0.3 in the last common ancestor of the Tokyo and Shanghai population then it could have been subjected to negative selection in the Shanghai population. d) Negative selection in the CEB population for allele A could account for the difference seen between the Shanghai sample and the CEB sample.
d) Negative selection in the CEB population for allele A could account for the difference seen between the Shanghai sample and the CEB sample.
The article argues that Darwin based his proposal for evolution by natural selection on four premises. If you released a group of genetically identical pigs into the wilds of western Massachusetts to fend for themselves they might slowly adapt to their environment (over many generations), but the population would not conform to one of the premises. Which one? a) Most organisms have stable populations. b) At least some of the organisms' variability is heritable. c) More offspring are produced than required for parental replacement. d) Organisms are variable.
d) Organisms are variable.
Looking specifically at figure 4 from the hardy weinberg article (included below), at what allele frequency will you have the highest number of heterozygotes? Assume that there are only two alleles of a gene. One allele is p the other is q. a) When q>0.8 b) When p>0.8 c) When P>q d) When P=q e) When 2pq=q2=p2
d) When P=q
Dogs (Canis lupus familiaris) and gray wolves (Canis lupus) can interbreed to produce viable, fertile offspring. These species shared a common ancestor recently (in geologic time) and have a high degree of genetic similarity, although their anatomies vary widely. Judging from this evidence, which two species concepts are most likely to place dogs and wolves together into a single species? a) ecological and morphological b) morphological and phylogenetic c) biological and morphological d) biological and phylogenetic e) ecological and phylogenetic
d) biological and phylogenetic
A bacteriologist is studying two asexually reproducing strains of E. coli. The two require different amounts of trace minerals for survival; on these grounds, the bacteriologist determines that they are separate species. In making his determination, he is using what species concept? a) none of the above b) biological species concept c) morophospecies concept d) ecological species concept e) evolutionary species concept
d) ecological species concept
What does the biological species concept use as the primary criterion for determining species boundaries? a) molecular (DNA, RNA, protein) similarity b) geographic isolation c) niche differences d) gene flow (the ability to exchange alleles and genes during reproduction) e) morphological similarity
d) gene flow (the ability to exchange alleles and genes during reproduction)
In contrast to positive and negative selection, _______ favors the extremes instead of the the intermediate forms in a continuously varied trait .
disruptive
True or False: In the c. coli long-term evolution experiment, the mutation allowing the e. coli to metabolize citrate occurred in order to help the e. coli grow on citrate. That is, if the e. coli were growing in some other condition, the mutation definitely would not have happened.
false
true or false: The Galapagos finches intentionally changed their beak sizes so that they could have access to the more plentiful seeds after the 1977 drought.
false
Another scenario in which populations might experience a strong influence of genetic drift is if some portion of the population leaves to start a new population in a new location or if a physical barrier divides a population.
founder effect
the flow of alleles in and out of a population due to the migration of individuals or gametes
gene flow
Allelic variety in a population (not an individual)
genetic variation
Traits that may be passed on to the next generation
heritable traits
yes or no You find that a wild population of antelope is not in Hardy-Weinberg equilibrium. From this information alone, can you determine whether natural selection is occurring?
no
Traits that are not passed to the next generation
non-heritable traits
From an evolutionary perspective, germ-line mutations are more significant than somatic mutations. This is because:
only germ-line mutations will appear in an individual's descendants.
The result of gene flow between populations is to ________ genetic differences among populations
reduce
Which population characteristics will make genetic drift more likely: small or large
small population is more likely
true or false: If a population is all homozygous at some particular gene locus and there are no mutations, natural selection cannot lead to change in the traits associated with that gene.
true
