Bio exam prep

Taxis definition

A directional response in animals involving the movement of the animal either towards or away from the directional external stimulus

Kinesis definition

A non-directional response in animals where the rate of movement or turning is influenced by the external stimulus

Tropism definition

A directional growth response in plants to a directional external stimulus

Nastic response definition

A non-directional response in plants to the intensity of a stimulus

Orthokinesis definition

A change in the speed of an animal's movement, where the movement is faster in unfavourable conditions and slower in favourable conditions

Klinokinesis definition

A change in the rate of turning of an organism. The rate of turning is faster in unfavourable conditions and slower in favourable conditions

Survival advantage of birds/bees flying between plants to pollinate them (1/2)

Cross pollination/increased genetic diversity

Survival advantage of birds/bees flying between plants to pollinate them (2/2)

Reduces competition between plants because if the plant dropped its seeds beneath it, the new plant would be competing for survival with the old plant

Benefits of migration

Remain in favourable conditions
Constant supply of food
Reduces diseases as they don't always have a host
Reduces predation; if the predators don't always have food there will be less of them
Increases genetic diversity as they can breed with individuals from a different population

Many benefits outweigh extreme energy costs

Benefits of phototropism

By bending towards the light the plant is able to increase its rate of photosynthesis therefore growing quicker and having a higher chance of survival

Predation

One animal species eats members of another animal species

Herbivory

An animal species eats part of a plant species

Competition

Members of different species compete for the same resources

Parasitism

Members of one species live on or inside members of another species, feeding off them

Mutualism

Two species provide each other with different resources

Commensalism

One species benefits from or aids another species while not being affected itself