CCA Crop Growth and Development 2 — Questions and Answers
Question 1: Which plant hormone is primarily responsible for promoting stem elongation and fruit development?
- Abscisic acid
- Cytokinin
- Gibberellin (Correct answer)
- Ethylene
Correct answer: Gibberellin
Gibberellins promote cell elongation, stem growth, and fruit development in many crop species.
Question 2: The process by which a plant converts light energy into chemical energy is called:
- Respiration
- Transpiration
- Photosynthesis (Correct answer)
- Photoperiodism
Correct answer: Photosynthesis
Photosynthesis uses sunlight, CO2, and water to produce glucose and oxygen in chloroplasts.
Question 3: What is the term for the minimum number of days required for a biennial crop to complete its life cycle?
- Vernalization period
- Juvenility phase (Correct answer)
- Photoperiod threshold
- Critical day length
Correct answer: Juvenility phase
The juvenility phase is the early growth period during which plants are incapable of flowering, regardless of environmental conditions.
Question 4: Which of the following best describes indeterminate crop growth habit?
- Plant ceases vegetative growth at flowering
- Plant continues vegetative growth while flowering and fruiting simultaneously (Correct answer)
- Plant produces all flowers at a single node
- Plant completes reproduction in one growing season only
Correct answer: Plant continues vegetative growth while flowering and fruiting simultaneously
Indeterminate plants like tomatoes and soybeans continue vegetative and reproductive growth concurrently throughout the season.
Question 5: In corn (maize), the V6 growth stage refers to:
- Six days after germination
- Six visible leaf collars (Correct answer)
- The sixth node below the ear
- Six weeks after planting
Correct answer: Six visible leaf collars
Corn vegetative stages are designated by the number of visible leaf collars, so V6 means six leaf collars are visible.
Question 6: Root growth is primarily driven by cell division occurring in which zone?
- Zone of maturation
- Zone of elongation
- Apical meristem (Correct answer)
- Root cap
Correct answer: Apical meristem
The apical meristem at the root tip is the primary site of cell division, driving root growth and elongation.
Question 7: Which environmental factor most directly controls the transition from vegetative to reproductive growth in photoperiod-sensitive crops?
- Temperature
- Soil moisture
- Night length (Correct answer)
- CO2 concentration
Correct answer: Night length
Photoperiod-sensitive crops respond to the length of the dark period (night) to trigger flowering at the appropriate season.
CCA Crop Growth and Development 2
Which plant hormone is primarily responsible for promoting stem elongation and fruit development?