1. What is the main role of cytokinins in cell division?
A.
They promote cell division
B.
They stop DNA replication
C.
They destroy dividing cells
D.
They prevent chromosome formation
Correct Answer:
They promote cell division
Explanation:
Cytokinins stimulate cell division by promoting the formation of new cells.
2. Cytokinins are especially important during which process in plant cells?
A.
Cell division
B.
Cell death
C.
Water loss
D.
Seed drying
Correct Answer:
Cell division
Explanation:
Cytokinins are plant hormones that play a major role in stimulating cell division.
3. Which stage of plant development is directly promoted by cytokinins?
A.
Formation of new cells
B.
Destruction of all cells
C.
Permanent stoppage of growth
D.
Loss of cell walls
Correct Answer:
Formation of new cells
Explanation:
By promoting cell division, cytokinins help form new plant cells.
4. In plant tissue culture, cytokinins help in the formation of a mass of actively dividing cells called:
A.
Callus
B.
Cuticle
C.
Xylem vessel
D.
Stoma
Correct Answer:
Callus
Explanation:
Cytokinins promote cell division in tissue culture, helping produce an undifferentiated mass of cells called callus.
5. Why are cytokinins added to tissue culture media?
A.
To stimulate cell division
B.
To prevent all cell growth
C.
To remove chromosomes from cells
D.
To stop the formation of new cells
Correct Answer:
To stimulate cell division
Explanation:
Cytokinins in tissue culture media encourage cells to divide and produce new plant tissue.
6. A plant cell culture shows increased cell division after a hormone is added. Which hormone is most likely responsible?
A.
Cytokinin
B.
Ethylene
C.
Abscisic acid
D.
Gibberellin
Correct Answer:
Cytokinin
Explanation:
Cytokinins are well known for stimulating cell division in plant tissues and cell cultures.
7. Cytokinins are named after their connection with which cellular process?
A.
Cytokinesis and cell division
B.
Photosynthetic pigment formation
C.
Water absorption by roots
D.
Pollen grain dispersal
Correct Answer:
Cytokinesis and cell division
Explanation:
The name cytokinin reflects their important role in cytokinesis and the division of plant cells.
8. Which result would be expected when cytokinin activity increases in a growing plant tissue?
A.
More cell divisions
B.
Fewer cell divisions
C.
Complete loss of cell nuclei
D.
Permanent arrest of the cell cycle
Correct Answer:
More cell divisions
Explanation:
Increased cytokinin activity generally promotes the division of cells in growing plant tissues.
9. Cytokinins are useful in micropropagation mainly because they promote:
A.
Rapid multiplication of plant cells
B.
Breakdown of plant tissues
C.
Destruction of growing points
D.
Inhibition of cell formation
Correct Answer:
Rapid multiplication of plant cells
Explanation:
Cytokinins stimulate cell division, allowing plant cells to multiply during micropropagation.
10. Which statement about cytokinins and cell division is correct?
A.
Cytokinins encourage plant cells to divide
B.
Cytokinins always prevent cell division
C.
Cytokinins remove the cell membrane before division
D.
Cytokinins convert every cell into a dead cell
Correct Answer:
Cytokinins encourage plant cells to divide
Explanation:
The primary function of cytokinins related to this subtopic is the promotion of plant cell division.
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