Plant Responses

Question 1

Autotrophs

Answer 1

Organisms that produce their own food (photosynthesis)

Question 2

Photosynthesis

Answer 2

Sunlight + Water + Carbon Dioxide → Oxygen + Glucose

Question 3

Tropisms

Answer 3

Plant Response: A directional and permanent change to the orientation of a plant’s growth in response to a stimulus: grow towards (positive) or grow away (negative)

Question 4

Nastic Responses

Answer 4

Non-direction and reversible movement of a plant in response to a stimulus where rate of movement is proportional to stimulus intensity

Question 5

Dormancy

Answer 5

Suspended growth due to climatic conditions. In dormant periods energy requirements are lowered and scare resources conserved

Question 6

Vernalisation

Answer 6

Flowering of plant to ensure reproductive developments and seed production occurs in spring and summer when bees are pollinating

Question 7

Abscission

Answer 7

Natural detachments of parts of a plant (leaves and ripe fruit)

Question 8

Germination

Answer 8

Growth from a seed

Question 9

Phytohormones

Answer 9

Plant growth hormones

Question 10

Auxin (IAA)

Answer 10

Produced in the cells of apical meristems (tips of shoots and roots) and transported to regions of growth: promotes elongation by increasing elastically of cell and promoting water intake

Question 11

Apical Meristems

Answer 11

Tips of shoots and roots; where IAA (Auxin) is produced

Question 12

Plumule

Answer 12

Shoot

Question 13

Radicle

Answer 13

Root

Question 14

Pulvini

Answer 14

Region attaching leave to steam containing large water cell creating turgor pressure

Question 15

Turgid

Answer 15

High water pressure making cell firm and rigid

Question 16

Flaccid

Answer 16

Low turgor pressure after ion transportation making cell soft and limp

Question 17

Ion Transportation

Answer 17

Ions pumped out of cell (potassium and chloride) promotes osmosis (water transport out of the cell through stomata)

Question 18

Nyctinasty

Answer 18

Night movement

Question 19

Photoperiodism

Answer 19

Physiological response to changes in the photoperiod: Plants sense hours of darkness not sunlight

Question 20

Noctoperiod

Answer 20

Hours of darkness

Question 21

SDP

Answer 21

Short-day plant
Long hours of darkness
Flowers in winter/autumn
Flowering inhibited by Pfr

Question 22

LDP

Answer 22

Long-day plant
Short hours of darkness
Flowers in spring/summer
Flowering induced by Pfr

Question 23

DNP

Answer 23

Day-neutral plant

Question 24

Phytochrome

Answer 24

Light sensitive protein made in leaves that controls the flowering of plants, it has two forms (Pfr and Pr)

Question 25

Pfr

Answer 25

Phytochrome far-red | Absorbs far-red light and rapidly converts it to Pr during day and slowly in darkness

Question 26

Pr

Answer 26

Phytochrome red | Absorbs red light and converts it to Pfr. Red light absorbed from the sun so Pfr is accumulated during the day

Question 27

Threshold Level

Answer 27

Level met when all Pfr is converted to Pr