Plant Growth and Development

Topics in this chapter

• Plant Growth and Mathematical Models
• Developmental Phases and Plasticity
• Plant Growth Regulators and Applications
• Photoperiodism and Vernalization

Cheat sheet

Practice questions

1. Question 1Q-C16A09

   Which of the following pairs of plant growth regulators (PGRs) is antagonistic in function with respect to seed dormancy and apical dominance respectively?

   1. A.ABA and Auxin; Gibberellin and Cytokinin
   2. B.Gibberellin and ABA; Auxin and Cytokinin
   3. C.Ethylene and Auxin; ABA and Gibberellin
   4. D.Cytokinin and ABA; Gibberellin and Auxin
   See the answer and solution
2. Question 2Q-42B857

   During arithmetic growth, if the initial length of a plant organ is $L_0$ and the growth rate is constant ($r$), the length after time $t$ ($L_t$) is expressed as:

   1. A.Lt = L0 * e^(rt)
   2. B.Lt = L0 + rt
   3. C.W1 = W0 * e^(rt)
   4. D.L0 = Lt + rt
   See the answer and solution
3. Question 3Q-92FB22

   The phenomenon in which plants follow different pathways in response to environment or phases of life to form different kinds of structures is called:

   1. A.Plasticity
   2. B.Heterophylly
   3. C.Differentiation
   4. D.Vernalization
   See the answer and solution
4. Question 4Q-6343BD

   Which of the following statements about plant growth regulators (PGRs) is incorrect?

   1. A.Auxin was isolated from tips of coleoptiles of oat seedlings.
   2. B.Gibberellins were discovered based on the 'bakanae' (foolish seedling) disease of rice.
   3. C.Kinin was isolated from autoclaved herring sperm DNA as kinetin.
   4. D.Abscisic acid was purified and chemically characterized as three independent substances: inhibitor-B, abscisin II, and dormin.
   See the answer and solution
5. Question 5Q-D4A7A1

   Which PGR is gaseous in nature and is primarily synthesized in large amounts by tissues undergoing ripening and senescence?

   1. A.Abscisic acid
   2. B.Ethylene
   3. C.Gibberellic acid
   4. D.Indole-3-acetic acid
   See the answer and solution