Question 1

Describe the unusual pollination system used by orchids of the genus Catasetum,which are pollinated by male euglossine bees.

Accepted Answer

The male flower attracts the bee by using a chemical similar to that used by bees to attract mates,and then shoots a pollinarium that adheres to the back of the bee.This pollinarium is then carried to the female flower,where it lodges onto the stigmatic cleft.

Question 2

Natural selection would appear to act against long tails in male red-collared widowbirds,given that longer tails reduce body condition over the mating season.Based on the experiments of Pryke and Andersson (2005),why do long tails appear to be favored despite their obvious disadvantage?

Accepted Answer

Long tails are favored in male red-collared widowbirds because females of the species are choosy,and they select mates based on longer tail length.

Question 3

Explain why male lions,after they have entered a new pride of female lions,will often engage in the practice of infanticide.

Accepted Answer

Male lions often kill offspring that have not yet been weaned from their mothers so that the females will physiologically be receptive to mating,thus improving the entering male's reproductive success.

Question 4

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

Accepted Answer

A)   males allowed to mate alone produced 2 1/2 times more sperm than those mating in the presence of other males
B)   males allowed to mate alone produced 2 1/2 times less sperm than those mating in the presence of other males
C)   males produced the same amount of sperm when they were allowed to mate alone or when they mated in the presence of other males
D)   males engaged in aggressive behavior when mating in the presence of other males

Question 5

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 6

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

Accepted Answer

A)   chose males that were the largest in the colony
B)   mated with more than one male
C)   extended the time of copulation with individual males
D)   established a large territory for mating

Question 7

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

A)   females
B)   males
C)   Both sexes are under equal sexual selection pressure.
D)   Neither sex is under sexual selection pressure.

Question 8

To study sexual dimorphism in humans,Napoleon Chagnon (1988)studied the Yąnomamö,a premodern tribe that live in the Amazon rain forest in Venezuela and Brazil.What specific trait of the Yąnomamö correlated with an increased number of wives a corresponding increased number of children?

Accepted Answer

The answer of To study sexual dimorphism in humans,Napoleon Chagnon...

Question 9

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

Accepted Answer

A)   sexual morphism
B)   male/female dimorphism
C)   sexual differentiation
D)   sexual dimorphism

Question 10

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 11

When male and female hangflies mate,the number of sperm transferred to the female increases linearly with an increased time of mating.What determines the length of time that male and female hangflies mate?

Accepted Answer

The answer of When male and female hangflies mate,the number...

Question 12

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

Accepted Answer

A)   applying pheromones that reduce the female's attractiveness
B)   the production of large ejaculates containing many sperm
C)   depositing a copulatory plug
D)   prolonged copulation during mating
E)   All of the above have been observed as traits of sperm competition.

Question 13

Describe the experiments that Adam Jones and colleagues (2002)used with rough-skinned newts to demonstrate the differential relative strength of sexual selection among between males and females.What is the significance that all females tend to mate with at least one male,and often with several males,whereas many of the males failed to mate and many mated only once or twice? Discuss whether sexual selection is a more potent force in the evolution of males or females,and why.

Accepted Answer

The answer of Describe the experiments that Adam Jones and...

Question 14

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

Accepted Answer

A)   many small flowers that attract male pollinators
B)   showy flowers that attract male pollinators
C)   flowers with large nectar-producing glands to attract male pollinators
D)   flowers where male and female flowers appear on the same plant

Question 15

According to the experiments of Delph and colleagues (1996),is sexual selection often stronger for male or female flowers,and what tends to drive this selection?

Accepted Answer

The answer of According to the experiments of Delph and...

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

A)   dark blue stripes and lateral spines
B)   bright orange stripes and skin folds on their bellies
C)   dark blue stripes and skin folds on their bellies
D)   lateral spines and skin folds on their bellies

Question 17

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

A)   the body mass index (BMI)  of men in their twenties, thirties, and forties for both marriage and producing offspring
B)   the weight of men in their twenties, thirties, and forties for both marriage and producing offspring
C)   the height of men in their twenties, thirties, and forties for both marriage and producing offspring
D)   the intelligence quotient (IQ)  of men in their twenties, thirties, and forties for both marriage and producing offspring

Question 18

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

Accepted Answer

A)   sexual success ratio
B)   sexual selection
C)   reproductive selection
D)   dimorphic selection

Question 19

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

A)   choosy; competitive
B)   aggressive; passive
C)   competitive; showy
D)   competitive; choosy

Question 20

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...

Exam 11: Sexual Selection

Describe the unusual pollination system used by orchids of the genus Catasetum,which are pollinated by male euglossine bees.

Natural selection would appear to act against long tails in male red-collared widowbirds,given that longer tails reduce body condition over the mating season.Based on the experiments of Pryke and Andersson (2005),why do long tails appear to be favored despite their obvious disadvantage?

Explain why male lions,after they have entered a new pride of female lions,will often engage in the practice of infanticide.

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

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]

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

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?