Chapter 7

Question 1

reproduction

Answer 1

can occur without sex (ie: ciliate cell division); growth involving fission, budding, eggs can develop without fertilization

Question 2

reproduction without sex (examples in depth)

Answer 2

Ciliate cell division: descendants are genetically identical (clone)

Colonial: individuals are genetically identical; if they are connected: comprise a module– each module may have come from a sexually formed zygote

Question 3

module organisms (examples)

Answer 3

formed form a sexually formed zygote

ie: brain coral, bryozoan, soft coral

Question 4

Cost of Sex

Answer 4

Female gives us 1/2 of her genes in progeny

sex involves an expenditure of energy and time to find mates and causes combat among males

Question 5

genetic diversity

Answer 5

sex increases combinations of genes- resistance against disease

Question 6

alternative to sex

Answer 6

clones must wait for mutations to occur- no diversity to allow evolutionary resistance to disease, stress

Question 7

Sex

Answer 7

recombination produces variable gene combinations, meiosis enhances crossing over chromosomes: new gene combinations and intragenic variants

Question 8

Natural Selection

Answer 8

evolution of new traits increase performance –> fitness

Question 9

Sexual Selection

Answer 9

for forms that breed more successfully– more claw of fiddler crabs, deer antlers, colors of male birds

Question 10

Natural v Sexual selection

Answer 10

can involve selection for display coloration. enhanced combat structures

female choice involved; select fit males (good gene hypothesis)

males may be trading off matings for handicap encumbered by sexual selection

Question 11

Fiddler crabs (sexual selection)

Answer 11

the major claw on fiddler crabs is used for display to attract females and to be in combat with other males; arises by intra-male sexual selection

Question 12

Types of Sexuality

Answer 12

Separate sexes: gonochoristic

Hermaphroditism: individual can have male or female function, simultaneous or sequential, during sexual maturity

Question 13

Barnacles

Answer 13

mate by copulating with neighbors…

Question 14

Hermaphroditism

Answer 14

Simultaneous: organs to make male and female gametes are present at the same time

Sequential: Protandrous-first male then female; protogynous: first female, then male

Question 15

Sequential Hermaphroditism

Answer 15

Protandry (oysters clams, polychaete worms)