Mastering Biology

morphological and phylogenetic

-accommodates asexual reproduction -species acceptance criteria can be subjective

genetic drift

-causes allele frequencies to fluctuate randomly -responsible for the bottleneck effect -responsible for the founder effect

natural selection

-consistently causes a population to become better adapted to its environment -cannot cause a harmful allele to become more common -a result of differential success in reproduction

fossil record

-discovery of shells of extinct species -discovery of transitional forms of horses

Which of the following are causes of evolutionary change?

-genetic drift -mutation -gene flow -natural selection

4 postulates of natural selection

-individuals in a population vary in the traits they possess -survival and reproductive success are variable among individuals in a population -individuals with certain traits are more likely to survive and reproduce -same trait differences are heritable

homology

-same genetic code in in fireflies and tobacco plants -vestigial pelvis in right whales -similarities in mammalian forelimbs

biogeography

-the high concentration of marsupial species in Australia -similarity of endemic island species to nearby mainland species

most general to most specific

1. reproductive isolating mechanism 2. pre zygotic isolating mechanism 3. gametic isolation 4. sperm-egg incompatibility in sea urchins

what is genetic drift?

a change in allele frequencies caused by random events

gene flow

a result of the movement of fertile individuals or their gametes -can introduce new alleles into a population's gene pool

How did thorns originate in roses?

a spontaneous mutation resulted in thorns and increased this rose's resistance to herbivory, selected by natural selection to be dominant in the population

Long necks make it easier for giraffes to reach leaves high on trees, while also making them better fighters in "neck wrestling" contests. In both cases, which kind of selection appears to have made giraffes the long-necked creatures they are today?

directional selection

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it

dismissed the idea that species are constant and emphasized the importance of variation and change in populations

Black-bellied seedcrackers have either small beaks (better for eating soft seeds) or large beaks (better for hard seeds). There are no seeds of intermediate hardness; therefore, which kind of selection acts on beak size in seedcrackers?

disruptive selection

Which type of selection tends to increase genetic variation?

disruptive selection

Heterozygote advantage refers to the tendency for heterozygous individuals to have better fitness than homozygous individuals. This higher fitness results in less genetic variation in the population.

false

Which species concept would be most useful to a team of biologists conducting a biodiversity survey?

the morphospecies concept

How many chromosomes would be found in an allopolyploid plant if its parents had diploid numbers of 2 and 10, respectively?

haploid number of 6

Which of the following statements is an accurate combination of postulates 1 and 2 of natural selection?

heritable variation exists for traits among individuals in a population

Traits that are derived from a common ancestor, like the bones of human arms and bird wings, are said to be

homologous

How does inbreeding alter genotype and allele frequencies?

homozygotes increase in frequency in the population over generations

Reinforcement is most likely to occur when

hybrids have lower fitness than either parent population

Which of the following evolutionary forces could create new genetic information in a population?

mutation

morphological

relies on similarities in structure

Which of the following evolutionary forces consistently results in adaptive changes in allele frequencies?

selection

Which statement about polyploidy is correct?

speciation by polyploidy may be almost instantaneous

Small Aristelliger lizards have difficulty defending territories, but large lizards are more likely to be preyed upon by owls. Which kind of selection acts on the adult body size of these lizards?

stabilizing selection

Women often have complications during labor while giving birth to very large babies, whereas very small babies tend to be underdeveloped. Which kind of selection is most likely at work regarding the birth weight of babies?

stabilizing selection

Which term is used to describe populations that live close enough to interbreed?

sympatry

What would be the ploidy of the viable gametes produced by a tetraploid individual if nondisjunction of all chromosomes occurred in meiosis I?

tetraploid

Which of the situations below describes vicariance?

the Grand Canyon forms, separating two populations of squirrels on the North Rim and the South Rim

Which statement about adaptation is correct?

the adaptive value of a trait varies as the environment changes

Which statement about genetic drift is correct?

the direction of evolutionary change due to genetic drift is random

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would happen in environments that lack antibiotics?

these bacteria would be outcompeted and replaced by bacteria that have lost these genes

Which of the following statements about autopolyploid individuals is true?

they contain more than 2 haploid sets of chromosomes

If a population is not in Hardy-Weinberg equilibrium for a specific gene, which statement is correct?

at least one of the Hardy-Weinberg assumptions has been broken

phylogenetic

based on evolutionary history

Which of the following is the most predictable outcome of increased gene flow between two populations?

deceased genetic difference between the two populations

genetic drift __________ genetic variation

decreases

direct observation of evolutionary change

development of drug resistance in bacteria

Which of the following are basic components of the Hardy-Weinberg model?

frequencies of two alleles in a gene pool before and after many random matings

When imbalances occur in the sex ratio of sexual species that have two sexes (that is, other than a 50:50 ratio), the members of the minority sex often receive a greater proportion of care and resources from parents than do the offspring of the majority sex. This is most clearly an example of

frequency-dependent selection

What prevents speciation from occurring in sympatric populations?

gene flow

mutation __________ genetic variation

increases

Which of the following describes dispersal?

individuals colonize a novel habitat

Which of the following statements is an accurate combination of postulates 3 and 4 of natural selection?

individuals experience differential success in their ability to survive or reproduce due to differences in certain traits

What occurs in a hybrid zone?

interbreeding

There is an island in the middle of a large river that houses a large population of ants. Damming of the river causes the island to flood and only the highest points of the island are now above water. The ants cannot swim, so are now in multiple isolated populations. Which of the following best describes this event?

isolation by vicariance

How might gene flow be important in managing an endangered population?

it increases genetic diversity by introducing alleles from one population into another

The fossil record resembles the living species in the same geographic area. How does this pattern support the theory of evolution by natural selection?

it is evidence that species can change over time

gene flow ___________ genetic variation of a population

may increase or decrease

selection _________________ genetic variation

may increase, decrease or maintain

what is biological fitness?

measures the reproductive success of an individual relative to others in the population

Generation-to-generation change in the allele frequencies in a population is

microevolution

Which evolutionary mechanism results in adaptation?

natural selection

reinforcement is a type of

natural selection

How can an allopolyploid plant become a biologically fit new species?

nondisjunction event during mitosis

biological

not applicable for extinct species

The Hardy-Weinberg model makes the following assumptions: no selection at the gene in question; no genetic drift; no gene flow; no mutation; random mating.

true

True or false? A flood that separates a population of frogs onto opposite sides of a lake is an example of a vicariance event that may result in allopatric speciation.

true

morphological, phylogenetic & biological

used by scientists in classification

which statement shows population thinking?

variation among individuals in a species is real and important