Floral Development (Lec)

Question 1

Refers to the developmental change in form or function of organs (especially leaves) as a plant matures.

Answer 1

Heteroblasty

Question 2

The floral whorls

Answer 2

Whorl 1: Sepals
Whorl 2: Petals
Whorl 3: Stamens
Whorl 4: Carpels

Question 3

Signals the influence phase change

Answer 3

• Light
• Carbohydrate supply
• Gibberellins
• Trehalose-6-phosphate (Arabidopsis)
• microRNAs

Question 4

The plant’s ability to measure day length (or night length) and use it to time developmental events like flowering, dormancy, or leaf drop

Answer 4

Photoperiodism

Question 5

Flowers under long continuous night conditions

Answer 5

Short Day Plants

Question 6

Flowers under short or interrupted nights

Answer 6

Long Day Plants

Question 7

Renders the dark period inefective

Answer 7

Night Breaks (Short exposure to light)

Question 8

Model that shows that plants flower when the internal circadian rhythm causes expression of a key gene (like CONSTANS, CO) at the same time that there is light in the environment

Answer 8

Coincidence Model

Question 9

The two types of phytochrome that detect red light and far red light

Answer 9

Pr and Pfr

Question 10

Pr and Pfr switching for Long Day Plants

Answer 10

• Red light (daylight):
  Pr → Pfr (active) → triggers growth, germination, flowering (in LDPs)
• Far-red light (shade or night): Pfr → Pr (inactive) → growth suppressed, flowering delayed (in LDPs)
• Darkness: Pfr slowly reverts to Pr (dark reversion)

Question 11

Process by which prolonged exposure to cold temperatures enables or accelerates a plant’s ability to flower

Answer 11

Vernalization

Question 12

Flowering signal that initiates the developmental switch from vegetative growth to flower formation

Answer 12

Florigen

Question 13

Key florigen protein that is produced in leaves when conditions are favorable

Answer 13

FT

Question 14

Suggested that the organs of the vegetating and flowering plant all originate from the leaf

Answer 14

Johann Wolfgang von Goethe

Question 15

The ABC model

Answer 15

• A: Sepals
• A+B: Petals
• B+C: Stamens
• C: Carpels

Question 16

Genes in the ABC model

Answer 16

• A: APETALLA1 and APETALLA2
• B: APETALLA3 and PISTILLATA
• C: AGAMOUS

Question 17

The ABCDE Model

Answer 17

• A+E: Sepals
• A+B+E: Petals
• B+C:+E Stamens
• C+E: Carpels
• C+D+E: Ovules

Question 18

Genes in the ABCDE Model

Answer 18

• A: APETALLA1 and APETALLA2
• B: APETALLA3 and PISTILLATA
• C: AGAMOUS
• D: SEEDSTICK and SHATTERPROOF
• E: SEPALLATA