Question 1

The differences between males and females of a species are called ________.

Accepted Answer

Sexual dimorphism refers to the differences in physical characteristics between males and females of a species. A and C are not commonly used terms to describe the differences between males and females, and B is not a technically accurate term as it suggests that there are only two distinct forms, when in reality there may be multiple variations within each sex.

Question 2

Selection for the ability to successfully compete with members of their own sex to mate with opposite sex is termed ________.

Accepted Answer

Intrasexual selection refers to the competition between members of the same sex for access to reproductive opportunities (i.e. mating with the opposite sex). This type of selection typically results in the evolution of traits that enhance the ability of individuals to compete for mates. Examples can include physical traits that make an individual more attractive to a potential mate, or behavioral strategies that allow an individual to outcompete rivals in mating contests. In contrast, intersexual selection refers to the preference of members of one sex for certain traits in members of the opposite sex, which can also drive the evolution of sexually dimorphic traits.

Question 3

In general,when sexual selection is strong for one sex and weak for the other,we can predict that members of the sex subject to strong sexual selection will be ________,and members of the sex subject to weak sexual selection will be ________.

Accepted Answer

When sexual selection is strong for one sex and weak for the other, members of the sex subject to strong sexual selection will evolve features that make them more competitive for mating opportunities, such as elaborate physical ornaments or displays, whereas members of the sex subject to weak sexual selection will be more choosy in selecting mates, as they have less competition. Therefore, choice D is the correct answer as it suggests that members of the sex with strong sexual selection are competitive and those with weak sexual selection will be choosy.

Question 4

Small,nonterritorial male marine iguanas typically have their mating interrupted by larger males prior to ejaculation.What alternative mating strategy have these small males developed to compensate for this?

Accepted Answer

Small, nonterritorial male marine iguanas have developed the ability to induce ejaculation prior to copulation, and store the ejaculate in their cloacal pouches. This allows them to compensate for the interruption of their mating by larger males and ensures successful fertilization.

Question 5

Experiments by Steve Tanner and colleagues (2000)with gray tree frogs demonstrated that female frogs preferentially mated with male frogs exhibiting ________.

Accepted Answer

Research by Steve Tanner and colleagues showed that female gray tree frogs are more attracted to males that produce longer calls, as these are likely indicators of the male's fitness and attractiveness.

Question 6

Which of the following has NOT been observed as a trait of sperm competition?

Accepted Answer

All of the options listed (A through D) have been observed as traits of sperm competition in various species. These strategies are employed to increase the likelihood of fertilization by one male over the sperm of other males.

Question 7

In male-male combat observed in marine iguanas,why do males tend to grow to sizes that exceed the optimal size for survival?

Accepted Answer

The answer of In male-male combat observed in marine iguanas,why...

Question 8

Pawlowski and colleagues (2000)gathered data from over 3,000 Polish men,and investigated the hypothesis that sexual dimorphism in humans is the result of female choice.They found that there was a slight but significant level of sexual selection on ________.

Accepted Answer

Pawlowski and colleagues found that there was a slight but significant level of sexual selection on the height of men in their twenties, thirties, and forties for both marriage and producing offspring. This suggests that female choice may indeed play a role in the evolution of sexual dimorphism in humans.

Question 9

A key event that determines reproductive success involves members of one sex choosing their mates from among the opposite sex,and is termed ________.[two words]

Accepted Answer

The answer of A key event that determines reproductive success...

Question 10

Adam Jones and colleagues (2002)demonstrated that in rough-skinned newts,all females tend to mate with at least one male,and often with several.What is the overall mating success for male rough-skinned newts,and what physical characteristic was selected for in males?

Accepted Answer

The answer of Adam Jones and colleagues (2002)demonstrated that in...

Question 11

A mating system in which at least some females mate with more than one male is termed ________.

Accepted Answer

Polyandry is the mating system where at least some females mate with more than one male. Vivipary refers to giving birth to live young, and polygyny and polygamy refer to mating systems in which males mate with more than one female.

Question 12

Adam Jones and colleagues (2000)studied the mating behaviors of broad-nosed pipefish (Syngnathus typhle)in a laboratory situation.For which sex is sexual selection a more potent evolutionary force?

Accepted Answer

The answer of Adam Jones and colleagues (2000)studied the mating...

Question 13

The energy and time expended constructing and caring for offspring is known as ________.[two words]

Accepted Answer

The answer of The energy and time expended constructing and...

Question 14

Which of the following statements is true regarding the involvement of sexual selection on male function (pollen donation)leading to sexual dimorphism in flowers?

Accepted Answer

All of the statements provided are true and reflect different aspects of how sexual selection influences male function in plants, leading to sexual dimorphism in flowers. Female flowers often receive more pollen than necessary, indicating a potential for selection on male traits to enhance pollen dispersal or attractiveness. The findings by Delph and colleagues, as well as Stanton and colleagues, further support the role of sexual selection in shaping flower traits related to male and female functions.

Question 15

In general,mothers typically make a larger parental investment in each offspring than males do.What is meant by the term parental investment?

Accepted Answer

The answer of In general,mothers typically make a larger parental...

Question 16

In studies on the pipefish Nerophis ophidion,females are larger than males and appear to be under greater sexual selection pressure than males.The females have two traits that male pipefish of the species lack.What are these two traits?

Accepted Answer

According to the passage, female Nerophis ophidion pipefish have two traits that males lack: dark blue stripes and skin folds on their bellies. Therefore, the correct answer is option C.

Question 17

Darwin called differential reproductive success due to variation among individuals in success at getting mates ________.

Accepted Answer

Darwin's term for differential reproductive success due to variation among individuals in success at getting mates is "sexual selection".

Question 18

In his study of the Mediterranean fruit flies (Ceratitis capitata),Matthew Gage (1991)found that ________.

Accepted Answer

The answer of In his study of the Mediterranean fruit...

Question 19

John Hoogland (1998)studied Gunnison's prairie dogs (Cynomys gunnisoni)and observed that an increase in litter size was observed when females ________.

Accepted Answer

Hoogland observed that female Gunnison's prairie dogs who mated with more than one male had larger litter sizes. This is because mating with multiple males increases genetic diversity and reduces the risk of inbreeding depression.

Question 20

Maureen Stanton and colleagues (1986),experimenting with wild radishes (Raphanus raphanistrum),demonstrated that sexual selection on male flowers has led to ________.

Accepted Answer

Maureen Stanton and colleagues demonstrated that sexual selection on male flowers of wild radishes has led to showy flowers that attract male pollinators. This suggests that the evolution of the flowers has been driven by male-male competition for access to female partners, leading to the development of traits that attract male pollinators.

Quiz 11: Sexual Selection

The differences between males and females of a species are called ________.

Selection for the ability to successfully compete with members of their own sex to mate with opposite sex is termed ________.

In general,when sexual selection is strong for one sex and weak for the other,we can predict that members of the sex subject to strong sexual selection will be ,and members of the sex subject to weak sexual selection will be .

Small,nonterritorial male marine iguanas typically have their mating interrupted by larger males prior to ejaculation.What alternative mating strategy have these small males developed to compensate for this?

Experiments by Steve Tanner and colleagues (2000) with gray tree frogs demonstrated that female frogs preferentially mated with male frogs exhibiting ________.

Which of the following has NOT been observed as a trait of sperm competition?

In male-male combat observed in marine iguanas,why do males tend to grow to sizes that exceed the optimal size for survival?

Pawlowski and colleagues (2000) gathered data from over 3,000 Polish men,and investigated the hypothesis that sexual dimorphism in humans is the result of female choice.They found that there was a slight but significant level of sexual selection on ________.

A key event that determines reproductive success involves members of one sex choosing their mates from among the opposite sex,and is termed ________.[two words]

Adam Jones and colleagues (2002)demonstrated that in rough-skinned newts,all females tend to mate with at least one male,and often with several.What is the overall mating success for male rough-skinned newts,and what physical characteristic was selected for in males?

A mating system in which at least some females mate with more than one male is termed ________.

Adam Jones and colleagues (2000) studied the mating behaviors of broad-nosed pipefish (Syngnathus typhle) in a laboratory situation.For which sex is sexual selection a more potent evolutionary force?

The energy and time expended constructing and caring for offspring is known as ________.[two words]

Which of the following statements is true regarding the involvement of sexual selection on male function (pollen donation) leading to sexual dimorphism in flowers?

In general,mothers typically make a larger parental investment in each offspring than males do.What is meant by the term parental investment?

In studies on the pipefish Nerophis ophidion,females are larger than males and appear to be under greater sexual selection pressure than males.The females have two traits that male pipefish of the species lack.What are these two traits?

Darwin called differential reproductive success due to variation among individuals in success at getting mates ________.

In his study of the Mediterranean fruit flies (Ceratitis capitata) ,Matthew Gage (1991) found that ________.

John Hoogland (1998) studied Gunnison's prairie dogs (Cynomys gunnisoni) and observed that an increase in litter size was observed when females ________.

Maureen Stanton and colleagues (1986) ,experimenting with wild radishes (Raphanus raphanistrum) ,demonstrated that sexual selection on male flowers has led to ________.