Question

1. macroevolution involves

a. formation of entirely new species over extended periods
b. changes in allele frequencies within a population
c. interbreeding of distinct species
d. small - scale changes within a species

1. which mechanism of reproductive isolation is illustrated by the differences in mating calls among frog species?

a. mechanical isolation
b. temporal isolation
c. behavioral isolation
d. geographical isolation

1. what defines extinction? (select all)

a. the temporary disappearance of a species
b. last individual of a species dying
c. reversible process caused by climate changes
d. irreversible loss of a species

1. what is the primary mechanism of evolution that induces the survival and reproduction of organisms with advantageous traits within a given environment?

a. genetic drift
b. gene flow
c. natural selection
d. mutation

1. what impact did climate fluctuations have on early humans?

a. hindered technological advancements
b. promoted migration without adaptation
c. decreased genetic diversity
d. forced adaptation to changing environments

1. what term refers to the internal body functions or processes that aid an organisms survival?

a. behavioral adaptations
b. structural adaptations
c. physiological adaptations
d. environmental adaptations

1. how does natural selection influence the traits of a population?

a. it randomly changes traits over generations
b. it ensures all individuals survive equally
c. it favors individuals with advantageous traits for their environment
d. it decreases all genetic variation

Explanation:

• Question 15: Macroevolution refers to large - scale evolutionary changes over extended periods, such as the formation of entirely new species. Option a is correct. Option b is microevolution (changes in allele frequencies within a population). Option c is incorrect as interbreeding of distinct species is not a definition of macroevolution. Option d is microevolution (small - scale changes within a species).
• Question 16: Behavioral isolation occurs when differences in behavior (like mating calls) prevent species from interbreeding. Frogs' different mating calls illustrate behavioral isolation. Mechanical isolation is about physical incompatibilities, temporal isolation is about timing differences, and geographical isolation is about spatial separation. So, option c is correct.
• Question 17: Extinction is the irreversible loss of a species (option d). The last individual of a species dying (option b) is also a part of the extinction concept. Option a is incorrect as it's not temporary. Option c is wrong as extinction is irreversible.
• Question 18: Natural selection is the mechanism that favors the survival and reproduction of organisms with advantageous traits in a given environment. Genetic drift is random change in allele frequencies, gene flow is the transfer of genes between populations, and mutation is a change in the DNA sequence. So, option c is correct.
• Question 19: Climate fluctuations forced early humans to adapt to changing environments. Option d is correct. There's no indication that it hindered technological advancements (option a). Migration was often with adaptation (not without, option b). There's no evidence of decreased genetic diversity (option c).
• Question 20: Physiological adaptations refer to internal body functions or processes that aid an organism's survival. Behavioral adaptations are about actions, structural adaptations are about physical structures, and there's no such thing as environmental adaptations in this context. So, option c is correct.
• Question 21: Natural selection gradually changes traits over generations. It doesn't mean all individuals survive equally (option b is wrong). It doesn't eliminate genetic variation (option d is wrong). Option a is correct as it acts on traits over time.

Answer:

1. a. Formation of entirely new species over extended periods
2. c. Behavioral isolation
3. b. Last individual of a species dying; d. Irreversible loss of a species
4. c. Natural selection
5. d. Forced adaptation to changing environments
6. c. Physiological adaptations
7. a. It gradually changes traits over generations