bio chapter 16
genotypes
Assortative mating can cause the frequency of _____ to change within a population.
gene flow
A Canada goose leaving it's population in order to mate with a goose from another population is an example of _______ ________.
alleles
A gene pool includes all of the _________ of all of the genes of a species.
population
A group of organisms of a single species living in the same geographic area is called a
founder effect
A type of genetic drift in which a small number of individuals form a new population away from the original one is called the ______.
assortative
A type of mating that occurs when individuals choose a mate with a preferred trait is called ______ mating.
benefit cost
According to cost-benefit analysis, the ______ of partaking in a particular behavior or strategy must outweigh the ______.
genepool
All of the alleles of all of the genes in a population is known as the _______.
population
All of the western blue birds living in a 100 hectare forest would be an example of a(n) ______.
sickle cell disease
An abnormal form of hemoglobin causes
there is no reproductive isolation to prevent gene flow
British land snails are an example of disruptive selection. in the grassy fields, the light-banded snails escape bird predators. in the darker forest, the dark snails survive and the light-banded snails are eaten. the different colored snails have the opportunity to interact and breed across the British landscape. why doesn't this "disruptive selection" eventually lead to two separate species?
variation
During times of environmental change, populations with genetic ____________ have a better chance of adapting.
alleles
Gene flow causes microevolution by introducing new or rare_____ into a population.
bacterium
Gonorrhea is becoming more difficult to treat because antibiotic resistance is developing in the ______ that causes gonorrhea
Required to defend against predators. Requires a larger amount of food.
Identify the negatives of being a dominant baboon. required to mate with more females Required to defend against predators. Requires a larger amount of food.
6 katydids in an isolated prairie
Identify the population that has the greatest chance of becoming reproductively isolated over time. 6 katydids in an isolated prairie 7 elk living in one of several neighboring herds in Colorado 300 geese living on a pond
Imperfections are a compromise for beneficial traits.
Identify why certain traits are not perfect.
genetics
If a scientist studies the diversity of genes in a population they are studying population ______
polygenic
If a trait is controlled by more than one gene, the trait is referred to as being ______.
reproductively
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.
access to mating
In examining male competition using cost-benefit analysis, the benefit that a male receives is in increased _____.
sexual dimorphism
In some animals the males and females differ in size and other characteristics. This is referred to as ______.
dominance
In some populations, high-ranking individuals have greater access to resources which cause males or females to establish ______ hierarchies
directional
Increases the frequency of an extreme form of a trait. The extreme phenotype is favored and the direction of the curve moves toward that phenotype during
100,000
It is estimated that a mutation occurs once in every _____ cell divisions.
disruptive selection
Maintains high levels of two different forms of a trait. The maintenance of two extreme phenotypes within a population in an environment that is subject to change results
monopolizing fertile females
Male baboons at the top of a dominance hierarchy benefit by _____.
genetic variation
Mutations serve as a source of new ___________ and are caused by changes to an organisms
adaptive
Natural selection favors the phenotype that is most _________.
Equilibrium
No mutations, no migration, random mating, no selection, and a large gene pool are required to maintain Hardy-Weinberg _______
gene
Population genetics studies the diversity of a population at the level of the ________.
dominance
Populations that have a structure in which higher-ranking animals have greater access to resources than lower-ranking animals are said to have _______ hierarchies.
malaria
Regions of Africa, in which populations have high frequencies of the sickle cell allele, will have high rates of _______ in their environments.
that females and males differ in size and other traits
Sexual dimorphism means ______.
compete selecting
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.
hemoglobin
Sickle-cell disease is caused by an abnormal form of ____ in red blood cells.
false; it causes imperfect adaptation
T OR F: Most adaptations resulting from natural selection are perfectly suited to the environment.
false
T or F: a population of organisms that reproduce asexually will display more variation than a population that reproduces sexually
true
T or F: the founder effect is an example of genetic drift in which rare alleles occur at a higher frequency in a population isolated from the general population
true
T or F: you have been studying a newly discovered species of lemur. you have established that sexual selection has been a powerful force in the evolution of this species and it is clear that female choice plays an important role in determining which males procure mates. after many hours of observation and data collection, you find that females prefer males that are proficient at collecting sap and fruit. you should conclude that your data strongly supports the good genes hypothesis
defensive
Territoriality relates to ______ behaviors.
resistance
The STD gonorrhea is becoming more difficult to treat due to the development of antibiotic
sexual
The adaptive changes in males and females that lead to an increased ability to secure a mate is called ______ mating
Microevolution
The allele and genotype changes occurring within a population is known as __________.
mating behavior
The alleles in nonrandom mating assort according to ______.
territory
The area that is defended against competitors is called a
natural disaster
The bottleneck effect is the loss of genetic diversity that can be caused by ______.
territoriality
The defensive behavior necessary to defend a territory is called
homozygous
The heterozygote advantage means that the heterozygote for a trait has an advantage over the two
stabilizing selection
The heterozygote advantage regarding sickle-cell disease is an example of
runaway
The hypothesis regarding sexual selection that states that females choose mates on the basis of appearance is called the _____ hypothesis.
good genes
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.
heterozygous
The maintenance of genetic diversity of future generations is often maintained through the _______ advantage
Because female peacocks choose to mate with males that have these ornate tails.
The peacock's tail is bright and showy and makes the male prone to predation. Why has natural selection not eliminated this trait from the population?
frequency
The percentage of each allele in a population's gene pool is referred to as an allele
mutations
The raw material for evolutionary change, which introduces new variations among members of a population is caused by _______.
it increases the populations chances of survival in changing environmental conditions.
Variation within a population is important because
frequency of the dominant allele
What does p represent in the Hardy-Weinberg principle?
frequencies will change
What will happen to the genotype frequencies of a population if assortative mating takes place?
genetic drift
When chance causes only certain members of a population to reproduce and pass on their alleles to the next generation it is called _____
non random
When individuals mate based upon preferences it is known as _____ mating
Hh
Which allele combination represents the heterozygote advantage? help maintain genetic diversity
typhoid fever
Which disease is associated with cystic fibrosis and thought to have kept the recessive allele within the population?
p2 + 2pq + q2
Which equation describes the genotype frequencies of a non-evolving population?
HbAHbS
Which genotype is most prevalent in regions of Africa that have high rates of malaria? have an advantage in environment where malaria is present
no selection no new members can join the population and no existing members can leave no mutation no genetic drift
Which of the following are conditions that a population must meet in order to maintain Hardy-Weinberg principle?
founder effect bottleneck effect
Which of the following are types of genetic drift?
disruptive
Which type of selection is most likely to persist in an environment that is subject to a high degree of change?
the percentage of each allele in a population
allele frequency is.....
directional
at the beginning of a research project on egg laying in seagulls, a researcher noted that the birds laid an average of 7.9 eggs per cloth. after studying the population for 15 generations, the researcher noted that the birds were now laying 3-4 eggs per clutch. What type of natural selection is occurring in the population of gulls
the founder effect
if the small groups of Viking explorers in Greenland and North America had survived and given rise to new populations, such a scenario would be an example of
have similar gene pools
if there is gene flow between 2 adjacent populations of the same species, then the 2 populations will
is evolution did not occur
in a population, the allele frequency for red flower color remained at 0.7 and the allele frequency for white flower at 0.3 for 6 generations. this ________ an example of a Hardy- Weinberg equilibrium in that _________
stabilizing
increases the frequency of an intermediate form of a trait. A selection type that has a large peak in the center of the range of distribution
bottleneck effect
the northern elephant seal was hunted almost to extinction during the 18th and 19th centuries. less than 100 seals were left to contribute to the gene pool of their future generations. since the early 20th century, the elephant seals have been protected by laws in both US and Mexico. over 100000 seals now inhabit western shores of North America, all related to the small population that survived the slaughter of hunters. scientists fear the elephants seals may be more susceptible to disease and pollution due to
heterozygous advantage
the recessive alleles for sickle cell anemia are more prevalent in regions of Africa where malaria is prevalent than it is in regions where there is no malaria. this is due to
mutation genetic recombination due to fertilization gene flow
variance within a population is maintained by
mutation
what condition is not necessary to maintain Hardy-Weinberg theory? -no selection -mutation -no migration -random mating
gene flow
the movement of alleles between populations.
directional selection occurs when one extreme phenotype in a population is favored disruptive selection favors 2 extreme phenotypes
what statements about natural selection are true? -directional selection occurs when one extreme phenotype in a population is favored -stabilizing selection favors all phenotypes equally -disruptive selection favors 2 extreme phenotypes -directional selection is most common in stable environments
small population (you need a large population)
which condition is not among the requirements of Hardy-Weinberg equilibrium? -random mating -no selection of phenotype -small population -no net mutations
random mating
which of the following conditions is necessary to maintain the Hardy-Weinberg equilibrium? random mating gene flow genetic drift mutations
all choices are correct
which of the following is required for natural selection to occur in a population? heritable variation accumulation of adaptive traits differential reproduction all choices are correct
it may lead to an allele becoming fixed in a population
which of the following is true about genetic drift? -it is more likely to occur in a large population than in a small population -it may lead to an allele becoming fixed in a population -it increases the number of heterozygous in a population -it increases the frequency of rare alleles in a population
mutagens
Chemical or physical agents that cause mutation are called
at any time, even where when bacteria are not exposed to the drug
mutations that result in resistance to specific antibiotics in bacterial organisms occur
All of the choices are correct
which of the following likely reflects the presence of one or more gene mutations? -fruit flies subjected to intense radiation produce a wider array of variable offspring -a chemical leaking from the surface of an old abandoned coal mine alters a regulatory gene so that a cricket nymph develops an extra set of eyes -the bacteria that causes gonorrhea, a common sexually transmitted disease, have previously been killed by penicillin; however, after continuous usage of the antibiotic, penicillin-resistant strains are now prevalent -radiation causes an alteration in a DNA nucleotide sequence, which is discovered when mapped, but which appears to be neither increasing nor decreasing in successive generations -all of the choices are correct
graph with a single tall and narrow peak located in the center a graph indicating gray guinea pigs have an advantage over black guinea pigs and white guinea pigs
you have done extensive research for 30 years on the frequency of coat colors (black, grey, white) in a guinea pig population located in the Andes Mountains. you suspect that your guinea pig population is undergoing stabilizing selection. if this is the case, what would you expect to find when you graph your data?