GEN 2313 CHPT 23 SMART BOOK
Consider a population and a gene present in this population as two alleles: F and f. For every 10 Ff individuals that survive to reproduce, 8 FF and 4 ff individuals survive to reproduce as well. If we assume that all individuals that survive to reproduce have roughly the same number of offspring, what is the relative fitness of the FF genotype in this case?
0.8
Arrange the principles of natural selection in the order in which they occur, with the first step at the top.
A mutation occurs Individuals with the mutation are more likely to reproduce Over the course of many generations, frequency of mutation increases
Which of the following would not be true for a population that is in Hardy-Weinberg equilibrium for a specific gene?
Natural selection favors individuals with a heterozygous genotype.
Consider a population of a hypothetical animal, whose fur color is determined by a single gene, called Col. From the list below choose all conditions that must be met in order for this population to be in Hardy-Weinberg equilibrium for the Col gene.
No new mutations in the Col gene. There is no natural selection. Animals in the population mate randomly, regardless of their genotype for the Col gene
Which of the following are likely reasons for differences in the reproductive success of different genotypes in a population?
Some genotypes are more likely to find mates than others. Some genotypes are more likely to survive to reproductive age than others. Some genotypes are more fertile than others.
How is the allele frequency of a population calculated?
The number of copies of the allele in the population is divided by the total number of all the alleles for the same gene in the population.
Which of the following correctly defines a population of sexually reproducing species for the purposes of population genetics?
a group of individuals that occupy the same area and can interbreed with each other
Consider a population of cheetahs, inhabiting a protected area in Africa. In 2012, there were 112 cheetahs in this population. During that year, 60 of those animals reproduced and 48 new cubs were born. What constitutes the gene pool of the new generation made of those 48 new cubs?
all of the alleles of every gene that were passed from the 60 parents to the 48 new cubs
Consider a population and a gene that has two alleles in this population, designated as P and p. If you divide the number of all the copies of the p allele in the population by the total number of copies of both alleles (P and p) in the population, you will calculate the ______ frequency of the ______.
allele; p allele
According to the principles of natural selection, a mutant allele will increase in the population if it is ______ to reproduction and survival.
beneficial
Population genetics is a field that is concerned with ______.
changes in genetic variation within a group of individuals over time
Individuals at one extreme of a phenotypic distribution are more likely to survive and reproduce in a particular environment due to _______________ selection.
directional
If a high chi square value is obtained when comparing observed and expected genotypes in a population, we can state that the population is in____________
disequilibrium
The Hardy-Weinberg equilibrium is a mathematical expression, which predicts that, when certain requirements are met, the allele and genotype frequencies of a gene in a population ______ over the course of many generations.
does not change
The Hardy-Weinberg equilibrium is used as a null hypothesis, i.e., if a population is in Hardy-Weinberg equilibrium, then ______.
evolutionary change is not occurring in this population
In order to derive the Hardy-Weinberg equation, the two originators assumed that ______ the population's gene pool.
gametes are formed from alleles independently chosen at random from
The ______ of a population consists of all of the alleles of every gene in all of the individuals of that population.
gene pool
Consider a population and a gene that has two alleles in this population, designated as D and d. If you divide the number of individuals with the genotype DD by the total number of individuals in the population, you will calculate the ______ frequency of the ______.
genotype; DD genotype
Which of the following phenomena is responsible for introducing new genetic variation in a population?
mutation
The mechanism of evolution through _________ ____________ was proposed by Charles Darwin and Russel Wallace in the 1850s.
natural selection
The mechanism of evolution through ____________ ____________ states that those individuals better adapted to their environment are more likely to survive and reproduce.
natural selection
A group of individuals of the same species, which occupy the same region, and can successfully interbreed with each other, is a(n) _____________of that sexually reproducing species.
population
The field that studies the extent of genetic variation within groups of people over time is called_________ genetics.
population
Microevolution is best described as ______.
the change in a population's gene pool from generation to generation
Which of the following is the best definition of Darwinian fitness as it relates to population genetics?
the relative likelihood that a genotype will contribute alleles to the next generation as compared to other genotypes
How can we calculate the frequency of a specific genotype in a population?
The number of individuals with this genotype in the population is divided by the total number of individuals in the population.
The change in a population's gene pool from one generation to the next is known as ______.
microevolution
Which of the following is an accurate depiction of the Hardy-Weinberg equation for a gene with two alleles?
p^2 + 2pq + q^2 = 1
Most of the traits in a healthy natural population exhibit some level of variation, or ___, that is, they are found in two or more forms.
polymorphism
When scientists study populations, they typically observe high levels of variation in many of the traits that characterize a species. In genetics, variations in traits at the population level are known as ______.
polymorphism
Suppose a chi square analysis is performed to test whether the observed genotypes in a population are consistent with the predictions of Hardy-Weinberg equilibrium. Which type of chi square value will be obtained if a population is in disequilibrium?
High
Two types of factors can govern microevolution. On one hand, mutation is a constant source of new genetic variation. On the other hand, mechanisms that alter existing genetic variation, such as natural selection and genetic drift, can act to alter existing genetic variation. How do those two types of factors compare in terms of the magnitude of their effect on allele frequencies in a population?
Mutations have a negligible effect on allelic frequencies, while mechanisms such as natural selection and drift can have a dramatic effect.