Biology Study Set

Which statement best describes microevolution?

Change in allele frequencies within a population from generation to generation

Which statement best describes macroevolution?

Evolutionary changes that produce new species or groups of species

How is natural selection best described?

A process in which individuals with traits conferring greater reproductive success become more common

Which pattern of natural selection favors individuals at one extreme of a phenotypic distribution?

Directional selection

Which pattern of natural selection favors intermediate phenotypes and selects against extreme phenotypes?

Stabilizing selection

Which pattern of natural selection favors two or more different genotypes that produce different phenotypes and is also called disruptive selection?

Diversifying selection

Which pattern of natural selection maintains genetic diversity and can produce a balanced polymorphism?

Balancing selection

Convergent evolution occurs when?

Different lineages independently evolve similar traits because they occupy similar environments

A homologous structure is a similarity that occurs because organisms?

Descended from a common ancestor

What is an example of a vestigial structure?

Human adult muscles used to wiggle the ears

Horizontal gene transfer is?

The incorporation of genetic material from another organism without being its offspring

Which set contains the three bacterial horizontal gene transfer mechanisms?

Transduction, transformation, conjugation

How is allele frequency calculated?

Number of copies of a specific allele / total number of alleles for that gene

How is genotype frequency calculated?

Number of individuals with a genotype / total number of individuals

For a gene with two alleles in Hardy-Weinberg notation, which equation represents allele frequencies?

p + q = 1

Which equation represents expected genotype frequencies under Hardy-Weinberg equilibrium?

p² + 2pq + q² = 1

Which is NOT a Hardy-Weinberg equilibrium condition?

Natural selection favors one genotype

What is genetic drift?

Changes in allele frequencies due to random chance

Bottleneck effect occurs when?

A population is dramatically reduced in size and allele frequencies change by drift

Founder effect occurs when?

A small group separates from a larger population and establishes a new colony

Gene flow caused by migration generally?

Decreases differences in allele frequencies between populations and can increase genetic diversity

Allopatric speciation occurs when?

A population becomes geographically isolated and evolves into one or more new species

Sympatric speciation occurs when?

Members within the same range diverge into different species without a physical barrier

A prezygotic isolating mechanisms?

Prevents formation of a zygote

A postzygotic isolating mechanism?

Blocks development of a viable and fertile individual after fertilization

Which sequence correctly lists the major taxonomic ranks from most inclusive to least inclusive?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Which choice follows the binomial nomenclature rules?

Canis lupus (genus capitalized; both words italicized

The light reactions of photosynthesis produce?

ATP, NADPH, and O2

When does photorespiration occur in C3 plants?

Rubisco combines RuBP with O2 instead of CO2

What is a monophyletic group?

A group that contains a common ancestor and all its descendants

What is a paraphyletic group?

A group that includes a common ancestor but not all its descendants

What is a polyphyletic group?

A group that does not include the most recent common ancestor of its members

What is the equation for photosynthesis?

6CO2 + 6H2O + light energy → C6H12O6 + 6O2

What are light reactions?

The first stage of photosynthesis where light energy is converted to chemical energy

What is photorespiration?

A process where oxygen is consumed and carbon dioxide is released, counteracting photosynthesis

What are C3 plants?

Plants that fix carbon dioxide directly through the Calvin cycle

What are C4 plants?

Plants that first fix carbon dioxide into a four-carbon compound before the Calvin cycle

Which statement best describes microevolution?

Change in allele frequencies within a population from generation to generation

Which statement best describes macroevolution?

Evolutionary changes that produce new species or groups of species

Natural selection is best described as:

A process in which individuals with traits conferring greater reproductive success become more common

Which pattern of natural selection favors individuals at one extreme of a phenotypic distribution?

Directional selection

Which pattern of natural selection favors two or more different genotypes?

Diversifying selection

Which pattern of natural selection maintains genetic diversity?

Balancing selection

Convergent evolution occurs when:

Different lineages independently evolve similar traits because they occupy similar environments

A homologous structure is a similarity that occurs because organisms:

Descended from a common ancestor

Which is an example of a vestigial structure?

Human adult muscles used to wiggle the ears

Horizontal gene transfer is:

The incorporation of genetic material from another organism without being its offspring

Which set contains the three bacterial horizontal gene transfer mechanisms?

Transduction, transformation, conjugation

Allele frequency is calculated as:

Number of copies of a specific allele / total number of alleles for that gene

How is genotype frequency calculated?

Number of individuals with a particular genotype / total number of individuals

What occurs during a bottleneck effect?

A population is dramatically reduced in size and allele frequencies change by drift

What is the effect of gene flow caused by migration?

Decreases differences in allele frequencies between populations and can increase genetic diversity

What occurs during allopatric speciation?

A population becomes geographically isolated and evolves into one or more new species

What occurs during sympatric speciation?

Members within the same range diverge into different species without a physical barrier

What is a prezygotic isolating mechanism?

Prevents formation of a zygote

What is a postzygotic isolating mechanism?

Blocks development of a viable and fertile individual after fertilization

What is the correct sequence of major taxonomic ranks from most inclusive to least inclusive?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Which choice follows the binomial nomenclature rules?

Canis lupus (genus capitalized; both words italicized)

What does a node represent in a phylogenetic tree?

A branch point where cladogenesis has occurred

What do the light reactions of photosynthesis produce?

ATP, NADPH, and O2