final exam
Assuming there are only two alleles at a given locus, if the frequency of the recessive allele is 0.3, what is the frequency of the dominant allele? 0.7 0.3 -0.3 0 0.5
0.7
All of the following statements about the Hardy-Weinberg equilibrium (HWE) are true except: Studying the deviations from the HWE model can allow biologists to evaluate which evolutionary mechanisms are acting on a population. Expectations of HWE are useful for predicting the approximate genotypic frequencies of a population from its allele frequencies. An ideal population that continually stayed in HWE would constantly evolve. After a perturbation, the genotypic frequencies of a population will return to HWE in a single generation if no evolutionary mechanisms are operating.
An ideal population that continually stayed in HWE would constantly evolve.
There are two isolated populations ("A" and "B") of an endangered plant species. Population A has had a constant size of 2,000 plants and population B has had a constant size of 250 plants. We most expect to see an increase in the frequency of deleterious alleles in population _ due to _. A; positive selection B; genetic drift A; genetic drift B; purifying selection B; positive selection
B; genetic drift
Which of the following statements about evolution is FALSE? Nonrandom mating can change the genetic makeup of populations over time. Evolution is goal-directed. Genetic drift can change the genetic makeup of populations over time. Natural selection is one of several mechanisms of evolution. Populations, not individuals, evolve.
Evolution is goal-directed.
The Hardy-Weinberg equilibrium is not applicable under which of the following conditions? Large population size Random mating No gene flow into or out of the population No mutations Mating under sexual selection
Mating under sexual selection
Suppose a hard frost in southern Florida wipes out nearly all of a population of plants. Even though the plant population recovers in numbers after a couple of decades, the genetic variation within that population remains much reduced. What is the most likely cause of the diminished genetic variation? Sexual selection dominance Population bottleneck Gene flow Purifying selection
Population bottleneck
___ selection operates if individuals within a population with the smallest and largest body sizes have fewer offspring than those of average body size. Sexual Disruptive Stablilizing Destabilizing Directional
Stablilizing
Natural selection _ on phenotypes and _ on genotypes. only acts indirectly; can act directly can act directly; only acts indirectly Natural selection cannot act on phenotypes, either directly or indirectly. only acts indirectly; only acts indirectly can act directly; can act directly
can act directly; only acts indirectly
uppose individual robins that have longer beaks have somewhat more offspring than those with shorter beaks, and that this has led to increases in beak length over time. We can say that beak size is associated with the _ of the robin, and that there is _ selection operating on beak size. fitness; stabilizing fitness; directional genetic structure; disruptive genetic structure; stabilizing genetic structure; directional
fitness; directional
Evolution by natural selection requires small populations. human breeding. diploid individuals. None of the provided answers are correct. genetic variation among individuals.
genetic variation among individuals.
