1. Which plant hormone helps prevent vivipary by maintaining seed dormancy?
A.
Auxin
B.
Gibberellin
C.
Abscisic acid
D.
Cytokinin
Correct Answer:
Abscisic acid
Explanation:
Abscisic acid maintains seed dormancy and prevents seeds from germinating while they are still attached to the parent plant.
2. Vivipary in plants refers to the germination of seeds while they are still attached to the:
A.
Root
B.
Parent plant
C.
Stem tip
D.
Leaf surface
Correct Answer:
Parent plant
Explanation:
Vivipary is the unusual germination of a seed before it has separated from the parent plant.
3. A deficiency of abscisic acid in a developing seed may result in:
A.
Delayed leaf fall
B.
Premature seed germination
C.
Increased flower color
D.
Thicker roots
Correct Answer:
Premature seed germination
Explanation:
Abscisic acid prevents vivipary by inhibiting premature germination during seed development.
4. The main role of abscisic acid in preventing vivipary is to promote:
A.
Seed dormancy
B.
Fruit ripening
C.
Stem elongation
D.
Pollen formation
Correct Answer:
Seed dormancy
Explanation:
Abscisic acid promotes and maintains dormancy, keeping the seed from germinating before it is released from the parent plant.
5. Which condition is prevented by adequate abscisic acid in a mature developing seed?
A.
Premature germination on the parent plant
B.
Normal seed dispersal
C.
Root growth after planting
D.
Water absorption during germination
Correct Answer:
Premature germination on the parent plant
Explanation:
Adequate abscisic acid keeps the seed dormant and prevents it from germinating while still attached to the parent plant.
6. In relation to vivipary prevention, abscisic acid acts mainly as a:
A.
Germination-promoting hormone
B.
Growth-inhibiting hormone
C.
Flower-opening hormone
D.
Fruit-coloring hormone
Correct Answer:
Growth-inhibiting hormone
Explanation:
Abscisic acid inhibits embryo growth and germination during seed development, thereby preventing vivipary.
7. What would most likely happen if the dormancy-promoting effect of abscisic acid were lost in a seed?
A.
The seed could germinate before dispersal
B.
The seed would never absorb water
C.
The seed would produce flowers immediately
D.
The seed would lose its embryo
Correct Answer:
The seed could germinate before dispersal
Explanation:
Loss of abscisic acid action can remove seed dormancy and allow premature germination, causing vivipary.
8. Abscisic acid prevents vivipary by keeping the embryo in a:
A.
Dormant state
B.
Flowering state
C.
Rapidly elongating state
D.
Fruit-ripening state
Correct Answer:
Dormant state
Explanation:
The embryo remains dormant because abscisic acid suppresses germination until suitable conditions occur after seed dispersal.
9. Which process is directly inhibited by abscisic acid to prevent vivipary?
A.
Seed germination
B.
Seed dispersal
C.
Fruit formation
D.
Leaf expansion
Correct Answer:
Seed germination
Explanation:
Abscisic acid inhibits germination in developing seeds, preventing them from sprouting while attached to the parent plant.
10. A seed that remains dormant on the parent plant is showing the effect of abscisic acid in:
A.
Preventing vivipary
B.
Increasing vivipary
C.
Promoting flowering
D.
Stimulating fruit cracking
Correct Answer:
Preventing vivipary
Explanation:
Maintaining dormancy on the parent plant is the role of abscisic acid that prevents premature germination, or vivipary.
Short questions are currently unavailable for this page.