Chpt 25: (8) Why Sex? Intro to Sexual Selection

Question 1

Sexual reproduction

Answer 1

formation of offspring WITH fusion of egg (female gamete) and sperm (male gamete)

Question 2

Parental investment differential: female strategy

Answer 2

be as selective as possible in mate selection

Question 3

Disadvantages of sex

Answer 3

1. it yields fewer offspring

2. It’s impossible to engage in when organisms are isolated from one another

Question 4

Parental investment differential

Answer 4

when one sex contributes more energy to offspring rearing than the other

Question 5

Parthenogenosis

Answer 5

when an unfertilized egg can develop into offspring

method of ASEXUAL reproduction

exp. from class: whiptail lizard pop all female

Question 6

Advantages of sex

Answer 6

1. it facilitates/increases variation; rapid production of new allele combos
2. Fewer deleterious alleles/harmful, random mutations get bred out of the population faster

Question 7

Budding

Answer 7

when offspring develop as an outgrowth of the parent

Question 8

Asexual reproduction

Answer 8

formation of offspring WITHOUT fusion of egg (female gamete) and sperm (male gamete)

Question 9

Skewed operational sex ratio

Answer 9

when more males are available to mate/reproduce than females

usually based on sperm:egg ratio

exp. pregnant females are not available to reproduce

Question 10

Parental investment differential: male strategy

Answer 10

be as opportunistic as possible in mate selection

mate a lot of times with a lot of females

Question 11

Fission

Answer 11

when parent splits into to organism of roughly the same size

Question 12

Sexual selection

Answer 12

when individuals with certain inherited characteristics are more likely than others to attract mates

form of natural selection

Question 13

Mutation Meltdown

Answer 13

the accumulation of harmful mutations in a small population, which reduces fitness and leads to extinction