Unit 2 KA 4 ✓ Flashcards
Sex and Behaviour (20 cards)
What is Parental Investment?
Parental investment is the energy invested by parents in the production of gametes and offspring. Females invest more resources than males do
What is the Female gamete?
The female gamete is a large, food-rich egg
NOTE: Requires more resources to produce than sperm
What is the Male gamete?
The male gamete is a tiny, mobile sperm
NOTE: Requires less resources to produce than an egg
What is Internal fertilisation?
(Pros + cons)
Internal fertilisation is when the male deposits his sperm directly into the females body.
Fertilisation is more likely to be successful, fewer eggs needed and survival rate of offspring is higher as they’re retained internally for protection/development.
However, a mate must be located and gametes must be tranferred directly between partners
e.g. Chickens
What is External fertilisation?
(Pros + cons)
External fertilisation is when the female and the male’s gametes unite outside the female’s body.
A very large number of offspring can be produced.
However, many gametes are predated/not fertilised and there is very little parental care so few offspring survive
e.g. Salmon (fish)
What is an r selected species?
Think r for rabbit
An r selected species is one that matures young, reproduces often, produce many small offspring with a high mortality rate and provide limited/no parental care. These species often occur in unstable environments where reproductive capacity hasn’t been reached
e.g. Rabbits, mice, salmon, most insects
What is a k selected species?
A k selected species is one that matures sexually at an older age, reproduces slower, produce fewer larger offspring with lower mortality rates and provide higher parental care. They are often found in stable environments
e.g. Elephants, Humpback whales, humans, some birds
What is Monogomy?
(Mono - one)
Monogomy is the mating of a pair of animals to the exclusion of all others
What is Polygamy?
(Poly - many)
Polygamy is when individuals of one sex have more than one mate
What is Polygyny
Polygyny is when one male mates exlusively with a group of females
NOTE: Try remember “gyny” as “guy” - looks similiar
What is Polyandry?
Polyandry is when one female mates with a number of males in the same breeding season
What is a Sign stimulus?
A sign stimulus is a trigger that provokes a behavioural response
What is a Fixed action pattern?
Fixed action pattern is an instinctive behavioural sequence that is relatively invarient within a species and almost inevitabley runs to completion.
They are a series of sign stimuli followed by responses
NOTE: Invaritent - the behaviour is the same throughout the species
e.g. Birds dancing to attract a mate
What is Sexual selection?
Sexual selection is the selection for characteristics that have little survival benefit for the indiviudal, however increases their chance of mating
e.g. Peacocks tail feathers don’t benefit its survival
What is Reversed sexual dimorphism
Reversed sexual dimorphism is when the females are more conspicous (bigger, more colourful etc) instead of the males.
What is an Honest signal?
An honest signal is a signal which can indicate favourable alleles, such as a low parasite burden, and a healthy individual. Traits which would increase the chances of survival of offspring (fitness)
What is a Lekking species?
A lekking species is a species that, during breeding season, males cluster at a communal area (known as a lek) to display and possibly fight to attract females. This allows female choice as the females can assess the honest signals of the males
e.g. Many bird species are lekking species
What is a Lek?
A lek is a communal area where males cluster during breeding season. Dominant males are in the middle, satellite males around the edge
What is a Satellite male?
A satellite male is a non-dominant male. They gather at the edge of a lek to increase their chances to mate with an intercepting female
What is Male-male rivalry?
Male-male rivalry is a form of sexual selection where males fight for dominance and access to females. Large size and weaponry increases access to females through conflict (real or ritualised)
