2.4 Sex and Behaviour

Question 1

number of gametes produced by males

Answer 1

large

Question 2

number of gametes produced by females

Answer 2

small

Question 3

size of energy store in males gametes

Answer 3

small

Question 4

size of energy store in female gametes

Answer 4

large

Question 5

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

Answer 5

females

Question 6

females invest in…

Answer 6

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

Question 7

parental investment is

Answer 7

costly but increases the probability of production and survival of young

Question 8

what can parental behaviour be classified into

Answer 8

r-selected species and k-selected species

Question 9

what are r-selected species

Answer 9

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

Question 10

what are k-selected species

Answer 10

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

Question 11

where does r-selection tend to occur

Answer 11

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

Question 12

where does k-selection tend to occur

Answer 12

in stable environments

Question 13

what is internal fertilisation

Answer 13

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

Question 14

what is external fertilisation

Answer 14

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

Question 15

benefits of internal fertilisation

Answer 15

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

Question 16

costs of internal fertilisation

Answer 16

a mate must be located which requires energy expenditure

requires direct transfer of gametes from one partner to another

Question 17

benefits of external fertilisation

Answer 17

very large numbers of offspring can be produced

Question 18

costs of external fertilisation

Answer 18

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

Question 19

what are mating systems based on

Answer 19

how many mates an individual has during one breeding season

Question 20

name the mating systems

Answer 20

monogamy

polygamy (polygyny and polyandry)

Question 21

what is monogamy

Answer 21

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

Question 22

what is polygamy

Answer 22

individuals of one sex have more than one mate

Question 23

what is polygyny

Answer 23

one male mates exclusively with a group of females

Question 24

what is polyandry

Answer 24

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

Question 25

many animals have...

Answer 25

mate-selection courtship rituals

Question 26

what are courtship rituals

Answer 26

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

Question 27

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

Answer 27

species-specific sign stimuli and fixed action pattern responses

Question 28

what does sexual selection select for

Answer 28

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

Question 29

what is sexual dimporphism

Answer 29

physical difference between males and females of a species

Question 30

many species exhibit sexual dimorphism as

Answer 30

a product of sexual selection

Question 31

what are females usually

Answer 31

inconspicuous

Question 32

what are males usually

Answer 32

have more conspicuous markings, structures and behaviours

Question 33

reversed sexual dimorphism occurs in...

Answer 33

some species such as vultures

Question 34

what is female choice

Answer 34

involves females assessing honest signals of the fitness of males

Question 35

what are honest signals

Answer 35

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

Question 36

what can honest signals indicate

Answer 36

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

Question 37

what is lekking

Answer 37

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

Question 38

what happens in a lek

Answer 38

males gather to display, where female choice occurs

Question 39

example of animal which exhibits lekking behaviour

Answer 39

birds

Question 40

how are the animals ordered in a lek

Answer 40

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

Question 41

what is a satellite male

Answer 41

male that sneaks to gain access to females

Question 42

what is a sneaker

Answer 42

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

Question 43

what increases access to females for mating

Answer 43

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

Question 44

what will males fight for

Answer 44

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