Free CPP Plant Propagation & Growth Management Questions and Answers — Questions and Answers
Question 1: Which propagation method involves placing a plant stem in soil while still attached to the parent plant?
- Grafting
- Layering (Correct answer)
- Cutting
- Division
Correct answer: Layering
Layering is a propagation method where a plant stem is encouraged to root while still attached to the parent plant. A section of the stem is typically buried in soil, and once roots develop, the new plant is then detached. This method provides the new plant with continuous support and nutrients from the parent until it can sustain itself independently.
Question 2: Which plant hormone is most associated with cell elongation and shoot growth?
- Auxins
- Ethylene
- Cytokinins
- Gibberellins (Correct answer)
Correct answer: Gibberellins
Gibberellins are a group of plant hormones primarily associated with promoting cell elongation and overall shoot growth. They play a crucial role in stimulating stem and internode lengthening, breaking seed dormancy, and influencing flowering and fruit development. Their action leads to taller, more elongated plant structures.
Question 3: Which propagation method is best for maintaining genetic uniformity?
- Seed propagation
- Cuttings (Correct answer)
- Grafting
- Stratification
Correct answer: Cuttings
Cuttings are the best propagation method for maintaining genetic uniformity because they produce clones of the parent plant. A cutting is a vegetative piece (stem, leaf, or root) taken from a single parent plant, and the new plant that develops from it is genetically identical. This ensures that all desirable traits of the parent are preserved.
Question 4: What is the function of cytokinin in plants?
- Stimulate flowering
- Induce dormancy
- Promote cell division (Correct answer)
- Inhibit root growth
Correct answer: Promote cell division
Cytokinins are a class of plant hormones that primarily promote cell division (cytokinesis) in plant roots and shoots. They play a vital role in regulating cell growth and differentiation, often working in conjunction with auxins to control plant development. Cytokinins also help delay the aging of leaves and promote bud development.
Question 5: What is the main advantage of seed propagation?
- Faster growth
- Genetic uniformity
- Genetic diversity (Correct answer)
- Pest resistance
Correct answer: Genetic diversity
The main advantage of seed propagation is the genetic diversity it introduces. Since seeds result from sexual reproduction, combining genetic material from two parent plants, the offspring exhibit variations. This diversity can lead to new varieties with improved traits, increased adaptability to changing environments, and enhanced disease resistance.
Question 6: Which method involves separating parts of a mature plant to grow new ones?
- Air layering
- Cutting
- Division (Correct answer)
- Seed stratification
Correct answer: Division
Division is a propagation method that involves separating parts of a mature plant to grow new ones. This technique is commonly used for plants that grow in clumps or have multiple crowns, such as many herbaceous perennials. Each separated section must have its own roots and shoots to establish itself as an independent plant.
Question 7: Which condition is crucial for rooting stem cuttings?
- Low humidity
- Direct sunlight
- High humidity (Correct answer)
- Cold temperatures
Correct answer: High humidity
High humidity is crucial for the successful rooting of stem cuttings. Cuttings initially lack roots to absorb water, so high humidity reduces water loss through transpiration from the leaves. This prevents wilting and allows the cutting to conserve moisture and energy, focusing its resources on developing new roots.
Question 8: What is the goal of pinching in growth management?
- Reduce growth rate
- Stimulate flowering only
- Encourage upward growth
- Promote bushier growth (Correct answer)
Correct answer: Promote bushier growth
The goal of pinching in growth management is to promote bushier growth in plants. By removing the growing tip (apical bud) of a stem, the plant's apical dominance is broken, which encourages the development of lateral buds. This results in more side branches, leading to a denser, more compact, and fuller plant habit.
Question 9: Which factor most affects the success rate of plant grafting?
- Leaf shape similarity
- Same plant height
- Cambium alignment (Correct answer)
- Time of day
Correct answer: Cambium alignment
The success rate of plant grafting is most critically affected by the precise alignment of the cambium layers of both the scion (the upper part) and the rootstock (the lower part). The cambium is the actively dividing tissue responsible for secondary growth, and its proper connection is essential for forming a vascular union that allows for water and nutrient transport between the two parts.
Free CPP Plant Propagation & Growth Management Questions and Answers
Which propagation method involves placing a plant stem in soil while still attached to the parent plant?