Key Area 4-Sex and Behaviour

Question 1

Describe egg production

Answer 1

Few we produced
Large energy store is required
Expensive to produce

Question 2

Describe sperm production

Answer 2

Many are produced
No energy store required
Cheap to produce

Question 3

What gamete requires the most parental care?

Answer 3

Egg cell

Question 4

Describe how the problems with sex in sessile organisms are overcome

Answer 4

Barnacles have a long penis that extends and swaps speed with the next barnacle
Coral has eggs and sperm released simultaneously in the water
Flowering plants reproduce with pollination where gametes are transferred from another to stigma of another

Question 5

What is internal fertilisation?

Answer 5

When there is no water in surrounding environment for the transfer of gametes

Question 6

What is external fertilisation?

Answer 6

When there is water in the surrounding environment for the transfer of gametes

Question 7

What are the benefits of internal fertilisation?

Answer 7

• fewer egg cells are produced
• high rate of reproductive success
• low mortality rate of offspring

Question 8

What are the costs of internal fertilisation?

Answer 8

• more energy invested per egg produced
• lots of energy invested in parental care
• protection for developing embryo must be given

Question 9

What are the benefits of external fertilisation?

Answer 9

• little energy invested in parental care

- good survival numbers due to sheer number of gametes produced

Question 10

What are the costs of external fertilisation?

Answer 10

• energy must be used to produce lots of gametes
• high mortality rate of gametes
• timing is difficult

Question 11

What is parental investment?

Answer 11

The energy given to the production of gametes and care of offspring

Question 12

How does parental care affect the offspring?

Answer 12

Parental investment increases the probability of production and survival of young

Question 13

How does the environmental conditions affect the offspring?

Answer 13

If the organism lives in a stable environment they will have few, expensive Young where energy investment is high.
If environment is unstable then many young are produced that get low energy investment and receive very little parental care.

Question 14

What are the two categories of parental care?

Answer 14

R-selected and K-selected

Question 15

Describe R-selected classification?

Answer 15

Young have relied development
Adults are of a small size
Many and small offspring
Short generation time

Question 16

Describe K-selected classification?

Answer 16

Young have slow development
Adult are of a large size
Few and large offspring
Long generation time

Question 17

What is the name given to the number of offspring?

Answer 17

Clutch size

Question 18

What are the limitations of using r and k selected classification?

Answer 18

Some organisms are difficult to place into one of these distinct groups and simplistic classification of parental investment into the two groups does not reflect continuous range of life history strategies

Question 19

What is optimal reproduction?

Answer 19

Based on the premise of a trade off in terms of the number and quality of current offspring versus potential further offspring

Question 20

What is polygamy?

Answer 20

Promiscuous and short lived interactions

Question 21

What is monogamy?

Answer 21

One partner and long term interactions

Question 22

Which reproductive strategies is more likely with more parental care?

Answer 22

Monogamous

Question 23

How is paternity a factor in choosing reproductive strategy?

Answer 23

With internal fertilisation the female is guaranteed to be the parent but preening is not guaranteed, so promiscuity or polygamy is more likely to ensure genes are passed on

Question 24

What is sexual dimorphism?

Answer 24

When makes and females look distinctly different

Question 25

How is sexual dimorphism arisen?

Answer 25

Sexual selection

Question 26

What are two ways males gain access to females?

Answer 26

• male-male rivalry~large size or weaponry

- sneaking~doesn’t follow female courtship

Question 27

How do the males look compared to females?

Answer 27

Males have more conspicuous markings, structures and behaviours than women

Question 28

What is female choice?

Answer 28

When females asses honest signals if the fitness in males

Question 29

What are two ways fitness can be assessed in males?

Answer 29

• good genes

- low parasite abundance

Question 30

What is an alternative strategy for choosing a mate?

Answer 30

Leaking~males meet in a Lek and display mating behaviour. Sneakers exist in the lek also.

Question 31

When is lekking commonly used?

Answer 31

When the only contribution is sperm

Question 32

What is reversed sexual dimorphism?

Answer 32

When the female is larger and more conspicuous than the male

Question 33

Where is reversed sexual dimorphism common?

Answer 33

In insects, birds of prey and some large mammals

Question 34

When does reverse sexual dimorphism occur?

Answer 34

If males have large distances to travel it makes sense to be smaller for energy expense

Question 35

What is species-specific stimuli?

Answer 35

A mating behaviour that relies on signals and stimuli to attract the female and ensures mating occurs when organisms are most fertile

Question 36

What is fixed-action pattern response?

Answer 36

The dance the males respond with to female presence

Question 37

What is imprinting?

Answer 37

The irreversible, tepid development process in young birds where they fixate on a larger object as they expect protection