2.4 Sex and Behaviour Flashcards Preview

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Flashcards in 2.4 Sex and Behaviour Deck (44)
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1
Q

number of gametes produced by males

A

large

2
Q

number of gametes produced by females

A

small

3
Q

size of energy store in males gametes

A

small

4
Q

size of energy store in female gametes

A

large

5
Q

who invests the most when it comes to parental investment in most species

A

females

6
Q

females invest in…

A

the egg structure in non-mammals or in the uterus during gestation in mammals

7
Q

parental investment is

A

costly but increases the probability of production and survival of young

8
Q

what can parental behaviour be classified into

A

r-selected species and k-selected species

9
Q

what are r-selected species

A

smaller organisms that usually produce larger numbers of offspring, providing no parental care, having shorter life spans and have a lower offspring survival probability

10
Q

what are k-selected species

A

larger organisms that usually produce lower numbers of offspring, providing more extensive parental care, have longer life spans and have a high offspring survival probability

11
Q

where does r-selection tend to occur

A

in unstable environments where the species has not reached its reproductive capacity

12
Q

where does k-selection tend to occur

A

in stable environments

13
Q

what is internal fertilisation

A

the process by which the sperm and egg nuclei fuse inside the female

14
Q

what is external fertilisation

A

the process by which teh sperm and egg nuclei fuse outside the female

15
Q

benefits of internal fertilisation

A

increased chance of successful fertilisation
fewer eggs needed
offspring can be retained internally for protection and/or development
higher offspring survival rate

16
Q

costs of internal fertilisation

A

a mate must be located which requires energy expenditure

requires direct transfer of gametes from one partner to another

17
Q

benefits of external fertilisation

A

very large numbers of offspring can be produced

18
Q

costs of external fertilisation

A

many gametes predated or not fertilised
no or limited parental care
few offspring survive

19
Q

what are mating systems based on

A

how many mates an individual has during one breeding season

20
Q

name the mating systems

A

monogamy

polygamy (polygyny and polyandry)

21
Q

what is monogamy

A

the mating of a pair of animals to the exclusion of all others

22
Q

what is polygamy

A

individuals of one sex have more than one mate

23
Q

what is polygyny

A

one male mates exclusively with a group of females

24
Q

what is polyandry

A

one female mates with a number of males in the same breeding season

25
Q

many animals have…

A

mate-selection courtship rituals

26
Q

what are courtship rituals

A

a set of display behaviours in which an animal, usually a male, attempts to attract a mate

27
Q

successful courtship behaviour in birds and fish can be a result of…

A

species-specific sign stimuli and fixed action pattern responses

28
Q

what does sexual selection select for

A

characteristics that have little survival benefit for the individual, but increase their chances of mating

29
Q

what is sexual dimporphism

A

physical difference between males and females of a species

30
Q

many species exhibit sexual dimorphism as

A

a product of sexual selection

31
Q

what are females usually

A

inconspicuous

32
Q

what are males usually

A

have more conspicuous markings, structures and behaviours

33
Q

reversed sexual dimorphism occurs in…

A

some species such as vultures

34
Q

what is female choice

A

involves females assessing honest signals of the fitness of males

35
Q

what are honest signals

A

signals and behaviour in animals that are a true representation of their biological fitness

36
Q

what can honest signals indicate

A

favourable alleles that increase the chances of survival of offspring (fitness) of a low parasite burden suggesting a healthy individual

37
Q

what is lekking

A

during a lek males will display for females in a communal display area, then females will chose a mate

38
Q

what happens in a lek

A

males gather to display, where female choice occurs

39
Q

example of animal which exhibits lekking behaviour

A

birds

40
Q

how are the animals ordered in a lek

A

dominant males occupy the centre of the lek, with subordinates and jubeniles at the fringes as ‘satellite’ males. during the display female choice occurs

41
Q

what is a satellite male

A

male that sneaks to gain access to females

42
Q

what is a sneaker

A

male that gains access to mate with females without the more dominant male knowing

43
Q

what increases access to females for mating

A

success in male-male rivalry through conflict (real or ritualised)

44
Q

what will males fight for

A

dominance and access to females, often using elaborate ‘weapons’ such as antlers, tusks, horns