Glossary 3031

Question 1

Abscission

Answer 1

Leaf fall from deciduous trees in autumn

Question 2

Abiotic environment

Answer 2

The non-living environment; the non-living influences on an organism.

Question 3

Acclimitisation

Answer 3

The ability of an organism to adjust its tolerance limits or optimum range to slow changes in the environment.

Question 4

Adaptation

Answer 4

An inherited characteristic that enables an organism to survive and reproduce in its habitat. Adaptions may be structural, behavioural or physiological.

Question 5

Allelopathy

Answer 5

The production of toxic chemicals in the roots and leaves of a plant that prohibit the growth of other plants.

Question 6

Auxin

Answer 6

A plant hormone that affects growth and development.

Question 7

Biotic environment

Answer 7

The living environment; the influences of living organisms on one another.

Question 8

Circadian

Answer 8

An event repeating itself about every 24 hours.

Question 9

Dirunal

Answer 9

Daily or circadian rhythm.

Question 10

Dormancy

Answer 10

A resting phase in an organism when metabolic rate falls to a low level.

Question 11

Ecological niche

Answer 11

A description of how the organism feeds, opportunities provided by the habitat and the adaptative features of the organism that allow it to take advantage of these opportunities.

Question 12

Ecosystem

Answer 12

A community of living organisms (biotic environment) together with non-living factors (abiotic environment), and the nutrient cycles and energy flows that connect all.

Question 13

Endogenous

Answer 13

A factor or stimulus that originates within an organism.

Question 14

Exogenous

Answer 14

A factor or stimulus that originates outside an organism.

Question 15

Habitat

Answer 15

The place where an organism lives.

Question 16

Long-day plants

Answer 16

Plants which flower in response to a day length longer than a critical period.

Question 17

Nastic response

Answer 17

A non-directional movement of part of a plant in response to an external environmental stimulus.

Question 18

Periodicity

Answer 18

Regularly changing behaviour.

Question 19

Photoperiod

Answer 19

The relative amount of light and darkness in a 24-hour period.

Question 20

Photoperiodism

Answer 20

A changing pattern or response based on length of light available.

Question 21

Phytochrome

Answer 21

A protein pigment in plants sensitive to red and infrared light.

Question 22

Plant hormone

Answer 22

A chemical that is produced in one part of the plant and has effects in another part.

Question 23

Short-day plants

Answer 23

Plants that flower in response to a day length shorter than a critical period.

Question 24

Stimulus

Answer 24

A change in the environment that causes a response in an organism.

Question 25

Symbiotic (mutualistic) association

Answer 25

An association between two organisms for their mutual benefit.

Question 26

Tolerance

Answer 26

An organism’s ability to survive variation in its environmental conditions.

Question 27

Tropism

Answer 27

A growth response made by plants to external stimuli in their abiotic environment.

Question 28

Vernalisation

Answer 28

The exposure of a plant to a period of low temperature to promote later growth and flowering.

Question 29

Turgor

Answer 29

The rigidity of the plant tissue due to inflation of the cells with water

Question 30

Haptonastic

Answer 30

Movements that are triggered by the intensity of touch.

Question 31

Effector

Answer 31

The region of the plant where the groeth response occurs

Question 32

Auxin

Answer 32

A plant hormone that affects growth and development

Question 33

Exogenous

Answer 33

A factor or stimulus that originates outside an organism.

Question 34

Endogenous

Answer 34

A factor or stimulus that originates within an organism.

Question 35

Vernalisation

Answer 35

The exposure of a plant to a period of low temperature to promote later growth and flowering.