Animal Societies

Question 1

What 3 types of mating systems are there

Answer 1

1. Monogamous
2. Polygamous
3. Promiscuous

Question 2

Define monogamy, serial monogamy and lifetime monogamy

Answer 2

Monogamy - only breed with one mate per season

Serial monogamy - find a new mate each season. Common in territorial animals

Lifetime monogamy - mate together for their lifespan

Question 3

What are the benefits of monogamy

Answer 3

Fitness - can mate with someone who produces high quality offspring

If resources are scarce reproductive success may be higher so male can help raise and defend offspring

Question 4

What are the 2 types of polygamy

Answer 4

1. Polyandry - females mate with multiple males

2. Polygyny - males mate with multiple females

Question 5

What is female defence polygyny

Answer 5

Females - have a shirt lifespan, are grouped together and only use sperm from one male

Males - give their sperm to all females in the same area so they can’t mate with other males

Question 6

Give an example of a polygamous method to mating

Answer 6

Leks - arena for mating defended by males

Males mate with many females in the lek e.g sandflies mate with all visiting females

Question 7

What is the sexy son hypothesis

Answer 7

Females will mate with attractive males so their sons will possess the genes to be attractive to females

Question 8

What are 3 benefits to polyandry in social insects

Answer 8

1. Sperm replenishment
2. Replacement of inferior sperm
3. Protection from predators

Question 9

What is a type of promiscuous mating system

Answer 9

Polygyandry - several males pair with several females

Question 10

What is a cost to females of promiscuous mating

Answer 10

Sperm carries diseases

Greater quantity of sperm they receive, higher risk of disease

Question 11

How do resources affect polygynous mating

Answer 11

Females follow resources - more resources they have the more offspring they produce e.g food, protection

Males follow females, more access to females more offspring they produce

If resources are fairly spread, females are widely dispersed and it benefits males to mate with more than 1 female

Question 12

How does the threshold model affect polygynous mating

Answer 12

Females have equal fitness by mating with a male with more than 1 mate. Territory and food supply may be better than other males even if being shared among more than 1 female

Question 13

Give an example of the threshold model

Answer 13

Female birds
Need shade in their territory
Will become a secondary female if their is shade

Question 14

What is an extra pair copulation

Answer 14

Males and females who mate with others in nearby territories

Question 15

What are 4 benefits of extra pair copulations

Answer 15

1. Increases the chances of all eggs being fertilised
2. Increases direct benefits e.g food
3. Maximises the genetic diversity of offspring
4. Can select males with good genes

Question 16

What is sperm competition

Answer 16

Direct competition between multiple males sperm to fertilise an egg

Question 17

Give an example of sperm competition

Answer 17

Dung flies - longer the copulation, more of the previous males sperm is displaced

Question 18

What is the kamikaze sperm hypothesis

Answer 18

Natural selection favours sperm designed to kill other males sperm over fertilising the egg