Topic 4C

Question 1

Monogamy

Answer 1

Single male & single female

Question 2

Polygyny

Answer 2

Single male & multiple females

Question 3

Polyandry

Answer 3

Multiple male & single female

Question 4

Polygynandry

Answer 4

Multiple male & multiple females

Question 5

List the main sexual strategies

Answer 5

1. Monogamy
2. Polygyny
3. Polyandry
4. Polygynandry

Question 6

List the 5 types of monogamy mates

Answer 6

1. Genetic
2. Social
3. Anonymous
4. Obligate
5. Facultative

Question 7

Genetic monogamy

Answer 7

Exlusive mating r/s b/w single male & single female

Question 8

Social monogamy

Answer 8

Paired males & females spending extensive periods of time together

Question 9

Anonymous monogamy

Answer 9

Incidental pairings occurring through proximity of a single male & female with no active choice/partner recognition

Question 10

Obligate monogamy

Answer 10

Males & females mate with single partner irrespective of resource abundance

Question 11

Facultative monogamy

Answer 11

Resource limitation in some locations constrains males into mating with a single female while polygynous mating occurs when resources are abundant

Question 12

Benefits of monogamy

Answer 12

1. ↑ reproductive successes –> males invest to produce more offspring than to invest in mate search (prominent in small populations)
2. Presence of parental care –> ↑ survival rate of offspring
3. Secure its own lineage –> females may use sperms of other males if let free to mate

Question 13

List the types of polyandry

Answer 13

1. Classical
2. Cooperative
3. Convenience

Question 14

Classical polyandry

Answer 14

Reversed sex roles –> individual male raises offspring with little/no help from female
E.g. pipefish: female transfer eggs to tail of males where he fertilises & carries it till hatching

Question 15

Cooperative polyandry

Answer 15

Subordinate males to share paternity & brood care with a dominant male
E.g. cichlids: females can control paternity of alpha & beta male by cryptic female choice

Question 16

Convenience polyandry

Answer 16

Females mate with multiple males to avoid aggressive breeding harassment form these males
E.g. sharks: males inflict injuries (bite pectoral fins/tails)/ males may work cooperatively to force mating

Question 17

List the benefits of polyandry

Answer 17

1. Fertility insurance
2. Good sperm competition
3. Sexy sperm competition
4. More resources
5. Better protection
6. Infanticide reduction
   (Beneficial strategy for females)

Question 18

Fertility insurance (benefit of polyandry)

Answer 18

More than 1 male may be required to fertilise eggs produced by highly fecund females; ↓ loss of investment

Question 19

Good sperm competition

benefit of polyandry

Answer 19

↑es the genetic variety of sperms available to the female –> chance

Question 20

Sexy sperm competition (benefit of polyandry)

Answer 20

↑es chance of having offspring w enhanced attractiveness from various males

Question 21

More resources (benefit of polyandry)

Answer 21

Females receive more parental care & resources from no. of male partners

Question 22

Infanticide reduction (benefit of polyandry)

Answer 22

Greater confusion of paternity & ↓ likelihood of losing offspring

Question 23

Better protection (benefit of polyandry)

Answer 23

Females receive protection from no. of protectors away from other harassing males

Question 24

Cuckholdry

Answer 24

• Alternate strategy to ↑ mating success
• Sneaker: used by smaller males during spawning dominated by larger males (hides & waits for chance to release gametes)
• Satellite male: large males develop coloration & behaviour hat mimics females (hover above spawning pair & slowly descend upon spawning)

Question 25

List the types of polygyny

Answer 25

1. Scramble competition 2. Female defense 3. Resource defense 4. Lek polygyny

Question 26

Scramble competition (polygyny)

Answer 26

Competition over accessible resources - Exist when there is high dd but low quantity of female gametes - Females are spatially dispersed & hard to find - Males race against time & compete with other males to look for mates - Males get equal share of resources as density increases

Question 27

Female defense

Answer 27

One male defends several females (specific territory) | - Males with greatest physical fitness & ability to defend mates = greatest contribution of gametes

Question 28

Resource defense (polygyny benefity)

Answer 28

One male attracts several females with the resources he defends (e.g. food, nesting sites)

Question 29

Lek polygyny

Answer 29

Group of males gather at a common site where females visit and select her mate --> may exhibit competitive displays to attract females (e.g. visual/auditory cues)

Question 30

List the benefits of polygyny

Answer 30

1. Increased fitness 2. Increased reproductive success (beneficial strategy for males)

Question 31

Increased fitness (benefit of polygyny)

Answer 31

↑ed chance of mating with females that has better DNA & ↑ed survival rate of offspring

Question 32

Increased reproductive success (benefit of polygyny)

Answer 32

Gain access to many fertile females = ↑ paternity

Question 33

Costs of polygyny

Answer 33

1. ↓ in genetic diversity: many offspring share one father --> ↑ chance of inbreeding 2. Incompetence to protect females from other males

Question 34

Benefits of polygynandry

Answer 34

1. Greater genetic diversity | 2. Greater dispersal into water column

Question 35

What is polygynandry commonly observed in

Answer 35

- Broadcast spawners - Forms huge mating shoals - Milky water due to milt

Question 36

Hermaphroditism

Answer 36

Individual having both reproductive organs of the male & female & have the ability to switch sexes

Question 37

Protogyny

Answer 37

Hermaphroditic fishes exist as females & switch to male | - When dominant male from the harem is removed --> largest female will switch to become male

Question 38

Protoandry

Answer 38

Hermaphroditic fishes exist as male & switch to females | - When larger size female dies, juvenile male switch to become female & form new pair

Question 39

Parthenogenesis

Answer 39

- Asexual reproduction method using diploid eggs - Embryo grows & develops w/o fertilization - Gynogenesis - Hybridogenesis

Question 40

Gynogenesis

Answer 40

Egg growth stimulated by presence of sperm | - Sperm cells do not contribute genetic materials to offspring

Question 41

Hybridogenesis

Answer 41

- Involves half of the genome intact from female & another half of genome recombined from new male - Takes place in sexual host