Uneven distribution of auxins may lead to
A. Phototropic curvature
B. Day-neutral curvature
C. Both (1) and (2)
D. None of the above
Answer: Phototrophic curvature
What are Auxins?
Auxins are plant hormones that regulate growth. Auxins also play a role in cell division and differentiation, in fruit development, in the formation of roots from cuttings, in the inhibition of lateral branching (apical dominance), and in leaf fall (abscission). Auxins are abundantly produced in meristematic region of the shoot. Auxins were discovered by botanist Fritz W. Went.
What are the functions of Auxins?
Auxin is a plant hormone that helps control the growth of plants. Auxin promotes cell growth and elongation of the plant. In the elongation process, auxin alters the plant wall plasticity making it easier for the plant to grow upwards. Auxins are responsible for rooting formations.
What is Phototropic curvature?
Plant phototropism describes a plant’s response to light. The Phototropic curvature is the result of uneven distribution of auxin. Charles Darwin and his son Francis Darwin observed that the coleoptiles of canary grass responded to unilateral illmination by growing towards the light source (phototropism).
Plant Growth and Development MCQs and Answers –Set-1
1. Which plant hormone helps in breaking the dormancy of plant?
2. Which hormone is formed in leaves and helps in the blooming of the flowers?
3. Which plant hormone is formed in injured cells by which the injury of plant is healed?
4. Which of the following hormone help in the cell division and development in the presence of auxins?
5. Name the plant hormone which increases the activity of cambium in the wooden plants?
6. Growth regulators, which control plant growth and development are called___________
7. Growth in plants is mainly driven by turgor pressure.
8. Which of the following is NOT a plant hormone?
9. Name the plant in which auxin was first discovered?
10. Which of the following is NOT a naturally occurring auxin?
Plant Growth and Development NEET MCQ –Set-2
1. Uneven distribution of auxins may lead to
2. Tendrils of garden peas coiling around any support signifies:
3. ____________ tissues synthesize natural cytokinins
4. ________ is a plant hormone generally present in the gaseous state
5. _________ is a colourless gas that serves as a signalling hormone.
6. Which plant hormone is responsible for saving the crops from falling.
7. Which of the following hormone is found in gaseous form?
8. Name the plant hormone which is responsible for the ripening of fruits?
9. Which plant hormone is helpful in making RNA and protein?
10. Which of the following statement is incorrect?
Important Questions on Plant Growth and Development –Set-3
1. The term auxin was coined by
2. Precursor of Indole acetic acid (natural auxin) is
3. All the following hormones are growth inhibitors except
4. Which of the following is a gaseous hormone
5. Which of the following bioassays are used to detect the presence of auxin
6. Coconut milk contains a cytokinin called ____ which promotes plant growth.
7. One of the following is not an auxin
8. _________can stimulate the germination of barley seeds
9. Seed dormancy is triggered by
10. The significance of the day length in plants was first shown in:
Plant Growth and Development NEET Questions –Set-4
1. A seed which is just waiting for favourable environmental condition to germinate is called
2. Richmond – Lang effect is
3. 2,4-D is used as
4. The type of germination in which cotyledons come above the ground is called as
5. In most of monocot plants, germination is
6. The phase of growth which is the first phase and represents lag phase of growth curve is
7. The lateral meristem in plant is responsible for
8. Plant growth can be measured by
9. Auxins were first isolated form the plants by
10. Apical dominance is due to
Plant Growth and Development Short Questions for NEET –Set-5
1. Identify the true statement/statements regarding growth and development in organisms.
2. Vernalization treatment can convert
3. Scarification is a method of overcoming dormancy in seeds which
4. Identify the precursor substance used in the biosynthesis of gibberellins in plants.
5. Seeds in which germination is stimulated by light are called
6. The chemical substances like phenolics, caumarins, ferulic acid are
7. The seeds which can not germinate in absence of light is called
8. Germination inhibitors leached out by one plant may inhibit germination of seeds of other plants is called as
9. The dormancy of seed is due to mechanical resistance of seed coat in
10. Which of the following growth harmones in plant is influenced by light?
Plant Growth and Development Class 11 questions and answers –Set-6
1. Name the amino acid which acts as a precursor of auxin biosynthesis?
2. Mark the one, which is NOT a physiological effect of auxin?
3. Name the site of Gibberellins synthesis
4. Gibberellin that is synthesized in the shoot transported to different parts of the plant by which medium?
5. What is bolting?
6. Which of the following plant hormone is responsible for seed germination?
7. Name the first naturally occurring cytokines.
8. Which of the following plant hormone causes a delay in leaf senescence?
9. Name the stress hormone of the plant.
10. Deficiency in which of the following hormone causes dwarfism in the plant?
Plant Growth and Development objective questions and Answers –Set-7
1. Who classified the plants into different categories on the basis of photoperiodic responses
2. The plant which needs light period shorter than critical period is called
3. Vernalization is also called as
4. The harmone which stimulates the flowering in vernalized plant is
5. Vernalization is
6. Epigeal germination is found in
7. Which of the following substance acts as natural germination inhibitor?
8. The part of seed which emerges out first during germination is
9. Indefinite growth of plants is due to presence of
10. In which of the following, rate of growth gradually slows down and comes to steady stage?