chapter 16 study questions
Assuming a Hardy-Weinberg equilibrium, what will the frequency of the homozygous dominant genotype be in the next generation if the frequency of the dominant allele in the current generation is 0.60?
0.36
What is the frequency of the recessive allele in a population if 16% of the individuals in the population have the recessive phenotype?
0.40
What is the frequency of a recessive allele in a population if 25% of the individuals are homozygous recessive and 50% are heterozygous?
0.50
Calculate the dominant allele frequency in a population if the homozygous dominant genotype frequency is 49%.
0.7
The bottleneck effect is the loss of genetic diversity that can be caused by ___________
A natural disaster
When an extreme phenotype is favored and the distribution curve shifts in that direction, _____ selection occurs.
Directional
What form of natural selection increases the frequency of an extreme form of a trait?
Directional selection
Which type of selection is most likely to persist in an environment that is subject to a high degree of change?
Disruptive
What form of natural selection maintains high levels of two different forms of a trait?
Disruptive selection
True or False: Most adaptations resulting from natural selection are perfectly suited to the environment.
False
When genetic drift occurs, resulting in rare alleles, or combinations of alleles, occuring at a higher frequency in a population isolated from the general population, this is called the _____________ effect.
Founder
Which of the following are types of genetic drift?
Founder Effect and Bottleneck Effect
What does p represent in the Hardy-Weinberg principle?
Frequency of the dominant allele
Which individuals have an advantage in an environment in which malaria is present?
HbAHbS
What are the five principles of the Hardy Weinberg Equilibrium?
NO mutation, natural selection, genetic drift, nonrandom mating, and gene flow.
What form of natural selection increases the frequency of an intermediate form of a trait?
Stabilizing selection
Which disease is associated with cystic fibrosis and thought to have kept the recessive allele within the population?
Typhoid fever
In examining male competition using cost-benefit analysis, the benefit that a male receives is in increased
access to mating
A gene pool includes all of the ___________ of all of the genes of a species
alleles
A type of mating that occurs when individuals choose a mate with a preferred trait is called __________ mating.
assortative
Antibiotic resistance is developing in the __________ that causes gonorrhea, making this disease more difficult to successfully treat.
bacterium
Sexual selection in males usually results in an increased ability to ______________ for mates, whereas sexual selection in females usually involves ______________ a mate with the best fitness
compete; choosing
Territoriality relates to ___________ behaviors.
defensive
Populations that have a structure in which higher-ranking animals have greater access to resources than lower-ranking animals are said to have _______________ hierarchies.
dominance
The ability to produce surviving offspring is called
fitness
The percentage of each allele in a population's gene pool is referred to as an allele ______________
frequency
A Canada goose leaving its population in order to mate with a goose from another population is an example of _______ ______
gene flow
The movement of alleles between populations is referred to as
gene flow
If a scientist studies the diversity of genes in a population they are studying population
genetics
Assortative mating can cause the frequency of ____________ to change within a population
genotypes
The hypothesis regarding sexual selection that states that females choose mates on the basis of traits that increase a male's chance of survival is called the _____________ hypothesis.
good genes
Sickle-cell disease is caused by an abnormal form of _________ in red blood cells.
hemoglobin
The maintenance of genetic diversity of future generations is often maintained through the ________________ advantage
heterozygote
Regarding sickle-cell disease, __________ individuals have both normal red blood cells and protection from malaria.
heterozygous
The heterozygote advantage means that the heterozygote for a trait has an advantage over the two ________________
homozygotes
During times of environmental change, populations with genetic ____________ have a better chance of adapting.
variation
A trait that is controlled by many genes is said to be a _______________ trait
polygenic
A _______________ is a group of organisms of a single species living in the same geographic area.
population
Microevolution refers to evolutionary changes within a _____________
population
If migration between populations does not occur, the gene pools of those populations may become different over time which can lead to the populations becoming _______________ isolated
reproductively
In some animals the males and females differ in size and other characteristics. This is referred to as _________
sexual dimorphism
An abnormal form of hemoglobin causes __________-_______ disease
sickle cell
The intermediate phenotype is the favored phenotype in ______________ selection
stabilizing
The area that is defended against competitors is called a
territory
Chemical or physical agents that cause mutation are called
mutagens
Mutations are changes to the _________ sequence, and serve as a source of new genetic variation.
DNA
The alleles in nonrandom mating assort according to
mating behavior
