bio 2 unit 3

Imagine you are studying a trait in a population that is in H-W equilibrium. The trait is controlled by a single locus with two alleles (A is dominant to a). You want to know the frequency of the dominant phenotype in this population. Which of the following terms is equivalent to the frequency of the dominant phenotype?

(p^2+2pq)

What is the frequency of the A allele in this population?

0

A population of squirrels is in HW. 64% of the individuals in this population display the recessive phenotype of a blonde tail. What percentage of the population is heterozygous for the dominant brown tail phenotype?

0.32

In a population of lizards that is in H-W equilibrium, 36% exhibit the recessive phenotype for color pattern. The dominant allele (a striped allele pattern) for this trait exhibits complete dominance over the recessive allele (a spotted pattern). What is the frequency of the dominant allele in this population?

0.4

A population of 100 fish on a reef is NOT in H-W equilibrium. For a color gene, 40 individuals are homozygous dominant, 50 are homozygous recessive, and the rest are heterozygous. What is the frequency of the recessive allele in this population?

0.55

A population of squirrels are in Hardy-Weinberg Equilibrium. The allele for brown fur (B) is dominant to the allele for grey fur (b). What is the frequency of allele b in the population if 36% of the squirrels display the dominant phenotype?

0.80

Let's pretend we have a population of N = 50 individuals.How many alleles for flower color are there in this population's gene pool?

100

What do you predict would result in the F2 cross between the dihybrid and homozygous recessive mutant if everything operated with normal independent assortment? (hint: draw 2 Punnett squares, then ask: what is the probability of each phenotypic combination?)

1:1:1:1 Gray/normal, Gray/vestigial, Black/normal, Black/vestigial

A population of space elephants on Everett's favorite planet is in H-W equilibrium for ear shape. Ear shape is controlled by a single locus with two alleles: A (round ears), which is completely dominant to a (star-shaped ears). 64% of these individuals display the recessive phenotype of star-shaped ears. What percentage of the population will be heterozygous for the dominant phenotype, round ears?

32%

We can describe our gene pool by looking at the frequency of an allele in the population. Assuming there are 100 total alleles in the population, and 40 of them are R......what is the frequency of the R allele in the pool?

40%

Which of the following is an example of genetic drift?

A random volcanic eruption removes all green crabs from the surviving population

What does it mean when we say a population is in Hardy-Weinberg Equilibrium?

Allele and genotype frequencies are constant

One of the conditions to maintain H-W is a large population size. Which of the following would you MOST LIKELY predict to happen if a population was very SMALL?

Alleles may become more easily fixed due to chance.

Which of the following is TRUE regarding allo and autopolyploidy?

Allopolyploidy involves the restoration of hybrid fertility

Imagine Darwin was having a conversation with someone, who argued that ENS is not possible because there is no evidence that natural selection is a plausible mechanism for species change. Which of Darwin's pieces of evidence would he use to counter this argument?

Artificial selection

which of the following reproductive isolating mechanisms would be MOST favored by natural selection? how do you know? Behavioral isolation Reduced hybrid viability

Behavioral isolation; this minimizes the amount of wasted resources and time on potentially unsuccessful offspring

Imagine there are two species of dragonfly that live in the same habitat. These species both breed during the fall. Males of both species perform an elaborate mating display for females. However, the type of display is different: males of species A fly in circles, while males of species B fly up and down. Given this information, which reproductive isolating mechanism is MOST likely at work here?

Behavioral, because males perform different mating rituals

What of the following BEST describes the relationship between natural selection, fitness, and adaptation?

Better adapted phenotypes increase in frequency in a population due to NS because they have greater relative fitness

You are studying a new species of alien on Mars, called the animorphs. The juveniles in this species look very different from the adults, and undergo several stages of metamorphosis during development. Populations of animorphs live in a region with other species, and you can easily observe animorph mating. Which species concept would be the most appropriate to use to identify the animorphs? Why?

Biological species concept, because this concept accommodates polymorphisms at different life stages

What is the relationship between diploidy, epistasis, and the maintenance of genetic variation?

Both diploidy and epistasis "protect" alleles from selection because these alleles are not expressed in the phenotype.

Which of the following trees depicts a DIFFERENT pattern of evolutionary relationship than the other two?

C

The Tasmanian wolf looks more like the North American red wolf than a kangaroo, but more closely related to the kangaroo. Which of the following is TRUE regarding this evolutionary relationship?

Convergent evolution led to analogous traits between the red wolf and Tasmanian wolf.

Which of the following describes a limitation of Darwin's ideas in The Origin of Species?

Darwin did not know the mechanism by which traits were inherited (but Mendel did).

Fertility is restored in hybrids after this polyploidy event. WHY?

Homologous chromosome pairs are restored.

Which of the following is NOT true regarding how the Biological Species Concept is well suited to the study of evolution?

Individuals are the unit of evolution with independent gene pools that allow different mutations to accumulate

What assumptions must be fulfilled for a population to be in Hardy-Weinberg Equilibrium?

Large population size

You are studying frogs in a rain forest. You want to define the various species you see based on measurable differences in body traits. You notice that females and males within the various species look extremely different from one another. Which species concept are you trying to use? Is this a good idea?

Morphological; no, because this species concept cannot account for polymorphism within a species

Imagine a population of animals that all have pink feathers (a genetically determined trait). Some individuals survive longer and reproduce more than others. Is feather color under ENS (evolution by natural selection) in this population?

No, because there is no variation in the feather color phenotype.

In a population of pink fairy armadillos, individuals exhibit no variation in body color. Individuals have no preference for body color when choosing mates. The population is very large, and when males reach sexual maturity, they leave this "home" population to find a new group of individuals to mate with. No mutations in body color have been recorded. Do you predict that this population will maintain H-W equilibrium for the trait of fin pattern over time? Why or why not?

No, because when males become adults they leave the population, and males from other populations can join this population.

In a population of stalk-eyed flies, males have different eyestalk lengths. Some males have very long stalks, while others have very short stalks. Males with long stalks can see predators better, but short-stalked males can move faster away from predators, making the survival of these males equal. This trait is heritable and passed on to offspring. Is this trait under evolution by natural selection? Why or why not?

No, there is no differential survival among phenotypes.

Imagine you study a population of different colored beetles. Some are purple and some are gold. These color morphs are controlled by a single gene with two alleles; G=gold and g=purple. Gold and purple beetles are equally likely to avoid predators and reproduce. Given this information, do you think the color morph trait is under natural selection in this population? Why or why not?

No; there is no differential survival and reproduction of phenotypes.

One of the conditions to maintain H-W is no mutation. Which of the following would you MOST LIKELY predict to happen if a single mutation occurred in a population?

Novel genetic variation (new traits) may arise.

Look at the phylogeny on the next page. Which of the following is TRUE about these evolutionary relationships?

Species A and species B are equally related to species C

In class, we reviewed the study on peppered moths conducted by Kettlewell (1950). Imagine you decide to conduct a similar study on lizards. You first need to identify a trait in a lizard population that maybe under natural selection. Which of the following traits is the BEST candidate?

Tail length in lizards is determined by a single locus. Lizards with longer tails are more likely to be caught by predators, but lizards with shorter tails are more likely to avoid predation.

Which of the following BEST explains why the Biological Species Concept is more useful for the study of evolution than the Morphological Species Concept?

The BSC allows for polymorphism

Imagine you went back in time and observed Darwin discussing his ideas with a colleague. The colleague says there is no evidence for evolution by natural selection because the constancy of species has not been questioned. In other words, there is no evidence that some species go extinct and new ones appear over evolutionary time. Which piece of evidence would Darwin MOST likely use to counter this argument?

The fossil record

Imagine that you are studying a population of anteaters that is in Hardy Weinberg equilibrium. In this population, 25% of the individuals display the recessive phenotype of short tongues (allele a). All other individuals in the population display the dominant phenotype (long tongues, allele A). Which of the following is FALSE regarding this population?

The frequency of homozygous dominant individuals is twice as big as the frequency of heterozygotes

How would the gene pool change if only individuals with red flowers were allowed to mate and reproduce? (i.e. natural selection is occurring)

The frequency of the red allele will increase

In a population of pink fairy armadillos, individuals exhibit no variation in body color. Individuals have no preference for body color when choosing mates. The population is very large, and when males reach sexual maturity, they leave this "home" population to find a new group of individuals to mate with. No mutations in body color have been recorded. Based on your answer to the previous question, select the best answer below.

The mechanism of evolution occurring in this population is gene flow.

Imagine you are studying ear length in a population of rabbits. Ear length in this population is controlled by a single locus with two alleles (A and a) exhibiting complete dominance. You have determined some characteristics of the population, including the following: -The population is very large -Rabbits with long ears are better able to avoid predators, compared to rabbits with short ears -There are 100 long-eared rabbits (50AA and 50Aa) and 25 short-eared (aa) rabbits Using this information, you set out to calculate allele and genotype frequencies. Which of the following is true regarding equations you could use to calculate these frequencies?

The sum of the genotype frequencies in this population will equal 1.

One of the conditions to maintain H-W is no gene flow (immigration or emigration). Which of the following would you MOST LIKELY predict to happen if gene flow occurred between two populations?

The two populations would have increasingly similar allele frequencies to each other.

In a large population of aye-ayes, individuals have large green or yellow eyes. Eye color is determined by a single locus, with two alleles: A = dominant green phenotype, and a = recessive yellow phenotype. Recently, you discovered an individual with blue eyes. Given what you know about mechanisms of evolution, which of the following would you predict?

This blue eye phenotype could be due to mutation or gene flow.

Andersson (1982) Intersexual selection Which mode of selection does this outcome resemble?

directional selection

Which group is the sister taxon to the group in the box?

frog, turtle, leopard

Which group represents the basal taxon in this tree?

lancelet

You are studying a population of 50 panda ants that is NOT in Hardy Weinberg equilibrium. You notice that 40 ants display the dominant black and white color pattern, while 10 ants display the recessive pink color pattern. You genotype the dominant phenotype ants and determine that all of these individuals are heterozygous. What are the allele frequencies (p = freq (black and white allele), q = freq (pink allele)) in this population?

p = 0.4, q = 0.6

A population of 30 bees is NOT in H-W equilibrium. For a gene that codes for wing type, there are two alleles: F (fast) and f (slow). F is dominant to f. In this population, 3 individuals are homozygous dominant, 6 individuals are heterozygous, and 21 individuals are homozygous recessive. What is the frequency of both alleles in this population?

p=0.2; q=0.8

A population of 45 aliens on Everett's second favorite planet is NOT in H-W equilibrium. In this population, antenna shape is determined by a single locus with two alleles exhibiting complete dominance: D (square antenna) is dominant over d (round antenna). You visit Pluto and count the following numbers of individuals with each possible genotype: 10 homozygous dominant individuals (AA) 7 heterozygous individuals (Aa) 28 homozygous recessive individuals (aa) What are the allele frequencies of D and d in this population?

p=0.3; q=0.7

Assume a population of frogs is in H-W equilibrium. You observe that frog croaks are controlled by a single locus with two alleles: B (loud croak) and b (quiet croak). The frequency of the quiet croak frogs in the population is 25%. What is the frequency of the dominant allele in this population?

p=0.5