Plant Regulators (from handout)

Question 1

light-sensitive photoreceptors that help plants detect changes in light
quality and duration.

Answer 1

Phytochrome

Question 2

It is a photomorphogenic pigment that absorbs red light and far-red light
wavelengths to induce photomorphogenesis.

Answer 2

Phytochrome

Question 3

structure of phytochromes consists of a protein part (___) and a prosthetic group
(____) that are synthesized in the nucleus and plastid of plants,
respectively

Answer 3

apoprotein;
phytochromobilin or chromophore;

Question 4

___enables light absorption, while the ___facilitates
signal transduction and interaction with other cellular components.

Answer 4

chromophore ;
apoprotein

Question 5

refers to the light-mediated developments in plants. The changes in
shape, structure, and function are results of plant responses to different wavelengths of light

Answer 5

Photomorphogenesis

Question 6

key processes involved in photomorphogenesis include

Answer 6

seed germination,
seedling development, and photoperiodism.

Question 7

____or when seedlings grow in dark, their hypocotyl elongates and the stem undergoes etiolation, where it grows and extends rapidly to reach a potential
light source.

Answer 7

Skotomorphogenesis

Question 8

there are specific photochromic receptors that mediate photomorphogenesis,
including __, ____ and, most especially, ___.

Answer 8

cryptochromes, phototropins, phytochromes

Question 9

– the underdeveloped leaves during etiolation spread out upon exposure to
light to further maximize light absorption.

Answer 9

Leaf expansion

Question 10

____ (stem shortening and thickening) – hypocotyl and stem elongation stop. The
stem becomes short and thick. At a cellular level, ___(intermediate type of plastids
that are not yet exposed to light) develops into chloroplasts.

Answer 10

De-etiolation;
etioplasts

Question 11

– occurs when a plant is subjected to the shade of another plant.

Answer 11

Shade avoidance

Question 12

Influence of Temperature (2)

Answer 12

Vernalization
Thermomorphogenesis

Question 13

• Elevated temperatures can lead to changes in plant
  growth and development, including flowering.

Answer 13

Thermomorphogenesis

Question 14

Influence of External Cues (3)

Answer 14

Photoperiod (light)
Thermoperiod (temperature)
Heat Stress:

Question 15

Photoperiod (light): 2

Answer 15

Photoperiodic Response:
Signal Transduction

Question 16

Thermoperiod (temperature): 2

Answer 16

Temperature Sensitivity:
Vernalization: