F215 4.1 - Plant Responses

Question 1

Tropism

Answer 1

A directional growth response in which the direction of the response is determined by the direction of the stimulus

Question 2

Phototropism

Answer 2

Directional response to light

Question 3

Geotropism

Answer 3

Directional response to the pull of gravity

Question 4

Chemotropism

Answer 4

Directional response to chemical stimulus

Question 5

Thigmotropism

Answer 5

Directional response to touch

Question 6

Positive tropic response

Answer 6

Plant responds by growing towards the stimulus

Question 7

Negative tropic response

Answer 7

Plant responds by growing away from the stimulus

Question 8

Plant hormones

Answer 8

Sometimes called plant growth regulators; co-ordinate plant responses to environmental stimuli Examples include auxins, abscissic acid, gibberellins, ethane, cytokinins

Question 9

Nastic response

Answer 9

A non-directional response to environmental stimuli

Question 10

Thigmonasty

Answer 10

Non- directional response to touch

Question 11

Photoperiodism

Answer 11

Flowering is response to a certain length of darkness

Question 12

Meristem

Answer 12

Groups of immature cells capable of dividing

Question 13

Node

Answer 13

Joint on stem

Question 14

Internode

Answer 14

Part of the stem between the nodes

Question 15

Apical meristem

Answer 15

Located in tips or apices of shoots and roots; responsible for roots and shoots getting longer because of cell division

Question 16

Lateral bud meristem

Answer 16

Located in buds, where side shoots originate

Question 17

Lateral meristem

Answer 17

Located in a cylindrical ring near the outside of roots and stems; responsible for roots and shoots getting wider by cell division

Question 18

Intercalary meristems

Answer 18

In some plants; located just above nodes (where leaves and branches branch off the stem); responsible for shoot getting longer by cell division

Question 19

Axillary bud

Answer 19

Lateral bud

Question 20

Apical bud

Answer 20

Bud at the tip of the shoot

Question 21

Expansins

Answer 21

Enzymes involved in breaking down cellulose cell walls during cell elongation

Question 22

Leaf petiole

Answer 22

Attaches leaf to stem; stalk of leaf

Question 23

Phototropin 1 and 2

Answer 23

Enzymes thought to be involved in phototropic response

Question 24

Leaf abscission

Answer 24

Leaf falling off stem

Question 25

Abscission zone

Answer 25

Layer of cells between the stem and the stalk of the leaf (petiole)

Question 26

Senescence

Answer 26

Getting old

Question 27

Cellulase

Answer 27

Enzyme that breaks down cellulose; involved in leaf abscission

Question 28

Apical dominance

Answer 28

The growing apical bud at the tip of the shoot inhibits the growth of the lateral buds further down the stem.

Question 29

Parthenocarpy

Answer 29

Growth of seedless fruit

Question 30

Malting

Answer 30

Germinating seeds produce amylase in the aleurone layer. This turns starch to maltose.

Question 31

Lodging

Answer 31

Stems of cereal crops bend over in the rain because of the weight of water in the ripened seed heads