Sex and behaviour Flashcards
What is the comparison of sperm and egg production in relation to?
Comparison of sperm and egg production is in relation to the number and energy store.
What sex has greater investment?
There is greater investment by females.
What increases the probability of production and survival of young?
Parental investment is costly but increases the probability of production and survival of young.
What is the classification of r-selected and K- selected organisms based on?
Classification of r-selected and K-selected organisms based on level of parental investment in offspring and number of offspring produced.
Where does r-selection occur?
R-selection tends to occur in unstable enviornments where the species has not reached its reproductive capacity.
Where does K-selection occur?
K-selection occurs in stable enviornments.
What is a benefit of external fertilisation?
Very large numbers of offspring can be produced.
What are the costs of external fertilisation?
Many gametes are predated or not fertilised, there is no or limited parental care given to offspring and few offspring survive.
What are the benefits of internal fertilisation?
There is an increased chance of successful fertilisation, fewer eggs are needed, offspring can be retained internally for protection and/or development and the is a higher offspring survival rate.
What are the costs of internal fertilisation?
A mate must be located which requires energy expenditure and it requires direct transfer of gametes from one partner to another.
How are mating systems based?
Mating systems are based on how many mates an individual has during one breeding season.
What are the different types of mating systems?
Polygamy and monogamy.
What do many animals have when mating?
Many animals have mate-selection courtship rituals.
What is successful courtship behaviour in birds and fish a result of?
Successful courtship behaviour in birds and fish can be a result of species-specific sign stimuli and fixed pattern responses.
What does sexual selection select for?
Sexual selection selects for characteristics that have little survival benefit for the individual, but increase their chances of mating.
