Orientation in Space

Question 1

what are tropisms

Answer 1

tropisms are directional responses to directional external stimulus

Question 2

what is a positive tropism

Answer 2

when the plant grows towards a stimulus

Question 3

what is a negative tropism

Answer 3

when the plant grows away from the stimulus

Question 4

what are some examples of stimuli

Answer 4

light
chemicals
gravity
water
physical contact or touch

Question 5

what are the types of tropisms based on stimuli

Answer 5

light = phototropism
chemical = chemotropism
gravity = gravitropism and geotropism
water = hydrotropism
temperature = thermotropism
physical contact or touch = thigmotropism

Question 6

why are tropisms important

Answer 6

tropisms are important as the plants can grow towards good things and away from harmful things that could kill them

Question 7

what are some general examples of positive and negative tropisms

Answer 7

plants will generally have a positive hydrotropism and positive phototropism as plants need water and sunlight to carry out photosynthesis
they will have a negative chemotropism as they will want to grow away from any harmful chemicals

Question 8

what tropism is known for being either positive or negative depending on the plant

Answer 8

thigmotropism

Question 9

what are nastic responses

Answer 9

nastic responses are non-directional responses to the intensity of the stimulus

Question 10

how are nastic responses different to tropisms

Answer 10

they aren’t always growth movements, a photonasty could be a flower opening up during the day and closing at night

Question 11

what is a hormone

Answer 11

a hormone is a molecule that is often produced in one location that will do stuff in another location

Question 12

what is auxin

Answer 12

auxin is a type of hormone

Question 13

where is auxin produced and what is the effect

Answer 13

auxin is produced in the plant shoots of plants and they cause cells to grow longer than normal

Question 14

what is the role of auxin in phototropism (draw diagram)

Answer 14

the plant shoot is exposed to light and auxin diffuses down the dark side of the plant, therefore the cell on the dark side grows longer- they elongate, and the part exposed to light does not grow and so the plant shoot grows towards the light

Question 15

what is the role of auxin in roots

Answer 15

auxin has the opposite effect in roots, it prevents the roots from elongating, with gravitropism the plant roots grow downwards, due to gravity auxin moves to the lowest side of the roots. The loss of auxin on the high side causes the cells to elongate while the cells on the lower side stay the same and the result is the roots start to bend and grow downwards

Question 16

what is a taxis response

Answer 16

a taxis response is a directional response involving the movement of the animal either towards or away from te directional external stimulus

Question 17

what is the difference between taxis response and tropisms

Answer 17

tropism are growth response in plants whereas taxis response is movement response in animals

Question 18

what is the difference between a positive and negative tais

Answer 18

moving towards the stimulus is a positive taxes and moving away from the stimulus is a negative taxes

Question 19

what are the types of taxes based on stimuli

Answer 19

light = phototaxis
chemical = chemotaxis
gravity = gravitaxis and geotaxis
water = hydrotaxis
temperature = thermotaxis
physical contact or touch = thigmotaxis

Question 20

what is the definition of kinesis

Answer 20

kinesis is a non directional response where the rate of movement or activity is influenced by the external stimulus

Question 21

what are the two types of kinesis

Answer 21

orthokinesis and klinokinesis

Question 22

what is orthokinesis and what is an example of orthokinesis

Answer 22

orthokinesis involves a change in the speed of an animals movement, where the movement is faster in un-favourable condition but slower in favourable condition, eg woodlice move slower when its really really humid

Question 23

what is klinokinesis and what is an example of klinokinesis

Answer 23

klinokinesis involves in the rate of the turning of organisms, the rate of turning is faster in unfavourable conditions nad slower in favourable conditions
eg flatworms turn more often where there is more light so that it ends up spending more time in the dark

Question 24

what is homing

Answer 24

homing involves an animal finding its way ‘home’ over unfamiliar areas often after migrating to new locations

Question 25

how can animals navigate

Answer 25

they can use landmarks such as rivers and mountains, even roads to navigate. some animals can use solar or magnetic compasses but following the direction of the sun of the direction of the earths magnetic field lines

Question 26

what is migration

Answer 26

migration is the regular movement of whole populations to a specified location

Question 27

what is important thing to know about migration

Answer 27

IT IS NOT RANDOM

Question 28

why do animals migrate

Answer 28

to move to a more favourable location for teh populations survival

Question 29

what are reasons for migration

Answer 29

food and breeding
they can move to a place with more food because their current location is going through a food shortage during a certain time of year
they can move to a place more appropriate for giving birth if their current location has predators or harmful weather etc

Question 30

what are some triggers and factors that play into migration

Answer 30

migration relies on internal and external factors

triggered by changing day length, changes in climate

Question 31

how is the animal prepared for migration

Answer 31

the internal clock can prepare the animal for migration and so the animal will know to increase their energy supplies for a long journey or increase fat layers for a cold journey, or some animals like birds can shed their feathers and replaces them with lighter ones to help