Plant orientation responses

Question 1

Abiotic factors

Answer 1

non-living physical and chemical components of the ecosystem

Question 2

Biotic factors

Answer 2

Living aspects of the environment that affect an organism

Question 3

Habitat

Answer 3

where it lives/eats

Question 4

Ecological niche

Answer 4

An organism is the perfect match of adaptations to its habitat

Question 5

Adaptative advantage

Answer 5

A reproductive benefit an organism derives from being well-suited to the environment in which it lives

Question 6

Adaptations

Answer 6

• Any traits that enable it to survive in its habitat
• Controlled by genes giving the organism a reproductive advantage

Question 7

Structural adaptation example

Answer 7

Long beak on kiwi

Question 8

Physiological adaptation example

Answer 8

Large eggs twice the size of the body of a kiwi

Question 9

Behavioural adaptation

Answer 9

Nocturnal for kiwis

Question 10

Orientation

Answer 10

Way in which the organism positions itself in response to stimulus from the environment

Question 11

Stimulus

Answer 11

Change in internal or external environment that evokes a response

Question 12

Light prefix

Answer 12

Photo

Question 13

Gravity prefix

Answer 13

Geo

Question 14

Temperature prefix

Answer 14

Thermo

Question 15

Water prefix

Answer 15

Hydro

Question 16

Chemicals prefix

Answer 16

Chemo

Question 17

Touch prefix

Answer 17

Thigmo

Question 18

Tropism

Answer 18

The growth response towards or away from an environmental stimulus in plants

Question 19

Direction of positive

Answer 19

Towards the environmental stimulus

Question 20

Direction of negative

Answer 20

Away from the environmental stimulus

Question 21

Auxin full name

Answer 21

Indoleacetic acid (IAA)

Question 22

Auxin

Answer 22

The plant growth hormone that controls the tropic response

Question 23

Where is auxin produced

Answer 23

• Growing tip of the shoot - meristematic tissue
• produced in high concs in apical meristem

Question 24

Auxin causes

Answer 24

elongation of the cells promoting upwards growth

Question 25

What happens when light is shone on auxin

Answer 25

Migrates to the dark side causing uneven plant tissue growth/elongation on one side

Question 26

Ethylene

Answer 26

Phytohormone that controls ripening of fruit

Question 27

Gibberellins

Answer 27

Phytohormone that controls the germination of seeds

Question 28

Cytokinins

Answer 28

Promotes cell division

Question 29

Abscisic acid

Answer 29

Phytohormone that controls the closing of stomata

Question 30

Adaptive advantages always relate back to

Answer 30

food, shelter, mates

Question 31

High concentration of auxin

Answer 31

Inhibits buds and roots but stimulates stems

Question 32

Nastic responses

Answer 32

Non-directional responses of the plants to stimulus

Question 33

Explain thigmonasty in terms of turgor pressure

Answer 33

• The hinge of the leaf called the pulvinus is filled with water
• when touched, rapid loss of water occurs
• loss of turgor pressure
• hinge collapses

Question 34

key adaptive advantages of nastic responses

Answer 34

• faster movements that avoids unfavourable conditions
• accesses resources

Question 35

Rate of frequency of responses increases as…

Answer 35

Intensity of stimulus increases

Question 36

Adaptive advantages of tropisms

Answer 36

• Growth towards favourable conditions eg. light, increased photosynthesis, growth, flowers, seeds
• Growth away from unfavourable conditions eg. chemicals