Practice Quizzes Part 1 Flashcards
As a population geneticist, you find a species of snails with more genetic diversity than humans. What does this mean?
There is more variety in the gene pool of snails than humans
From an evolutionary perspective, germ-line mutations are more significant than somatic mutations. This is because:
Somatic mutations affect only one or a few cells and only germ-line mutations will appear in an individual’s descendants
What is the result of a mutation that occurs in somatic cells?
The mutation may be expressed in the individual, but will not be passed along to its offspring
Why is genetic variation critical for evolution?
It is the source material for natural selection
Female starlings that lay clutches of four or five eggs have more surviving young than those with either larger or smaller clutches. This is an example of:
(A) genetic drift acting on clutch size
(B) directional selection acting on clutch size
(C) disruptive selection acting on clutch size
(D) stabilizing selection acting on clutch size
(D)
A particular gene in a given population of individuals has 2 alleles, A and a. The frequency of the A allele equals the frequency of the a allele. What are the expected genotype frequencies, assuming the population is in Hardy-Weinberg equilibrium?
AA=0.25
Aa=0.5
Aa=0.25
Using visual observation of phenotype to identify allele frequency rarely works because:
Multiple genes may control phenotype
Which of these 5 evolutionary forces is rare and usually not considered by population genetics?
- Non random mating
- Mutation
- Selection
- Immigration
- Genetic drift
Mutation
All the alleles present in all individuals in a species are referred to as the WHAT of that species?
Gene pool
If an assumption for the Hardy-Weinberg equation is violated, what does this mean?
(A) The allele frequencies or genotype frequencies are undergoing evolutionary change
(B) The population is adapted to its environment
(C) Mutations are increasing in frequency in the population
(D) An allele is fixed in the population
(A)
What term correctly describes change in allele frequency due to random effect of a small population?
- Immigration
- Selection
- Non random mating
- Genetic drift
- Mutation
- Genetic drift
Genetic variation in a population refers to…
Multiple alleles within a gene pool
In a hypothetical population for 1000 frogs there exists a gene with 2 alleles. 280 of the frogs are homozygous dominant (DD), and 220 are homozygous recessive (dd). What is the frequency of heterozygous in the population?
0.50
In genetics, two organisms are part of the same population if:
They are the same species and are in the same geographic area
What does the term 2pq represent in the Hardy-Weinberg relation?
The frequency of heterozygous
The differential success of alleles is called:
Selection
What does it mean to say that an allele is “fixed” in the population?
It is an indication of no genetic variation at that locus in the population
Genetic variation has two sources-mutation and:
Recombination
At the genetic level, evolution is:
A change in the frequency of an allele or genotype over time
The Hardy-Weinberg equilibrium has 5 conditions, what are they?
- A large breeding population
- Random mating
- No change in allele frequency due to mutation
- No immigration/emigration
- No natural selection
What are the 2 equations of Hardy-Weinberg equilibrium?
P + q = 1 P^2 + 2pq + q^2 =1 P=frequency of dominant allele Q=frequency of recessive allele P^2= frequency of homozygous dominant 2pq= frequency of heterozygous genotype Q^2= frequency of homozygous recessive
Ring species such as the greenish warbler complicate the biological species concept because:
At least some of their populations are reproductively isolated from one another but can still exchange genetic material
In some large groups of plants, including dandelions, oaks, and willows, the biological species concept is complicated because the process of WHAT allows gene flow to occur between good WHAT that can be Ashly distinguished based on appearance
- Hybridization; morphospecies
- Polyploidy; ring species
- Polyploidy; evolutionary species
- Hybridization; ecological species
- Allopathic speciation; ring species
- Hybridization; morphospecies
Unlike the biological species concept, the morphospecies concept relies on:
Phenotype