Plant Growth Regulators and Seed Dormancy Quiz

Plant Growth and Development

• Plant growth is the irreversible increase in size of a plant, resulting from cell division and expansion.
• The stages of plant development include:
  • Seed germination
  • Seedling establishment
  • Vegetative growth
  • Reproductive growth
  • Senescence

Phytohormones

• Phytohormones are plant hormones that regulate plant growth and development.
• Types of phytohormones include:
  • Auxins
  • Gibberellins
  • Cytokinins
  • Ethylene
  • Abscisic acid

Functions of Phytohormones

• Auxins promote cell division and differentiation in plants.
• Auxins are responsible for promoting shoot and bud development in plants.
• Ethylene is responsible for initiating the ripening of fruits in plants.
• Abscisic acid regulates the adaptation to drought in plants.

Auxin

• Indole-3-acetic acid (IAA) is the natural auxin.
• The effect of auxin when the shoot grows towards light is called phototropism.

Cellular Development

• The process of cells developing different forms adapted to specific functions is called cellular differentiation.
• The ability of an individual cell to reconstitute the entire plant part and functions is called totipotency.

Plant Defense Mechanisms

• Physical defense mechanisms that plants use against herbivores include:
  • Spines
  • Thorns
  • Hairs
  • Trichomes
• The exception is: Rhizome (Rhizome is a type of underground stem, not a defense mechanism)
• PAMP recognition in plants is the ability to recognize and respond to pathogen-associated molecular patterns (PAMPs).
• The purpose of PAMP recognition is to trigger an immune response against pathogens.

Plant Immunity

• The main function of effector-triggered immunity in plants is to provide specific resistance to pathogens.
• The difference between PAMP-triggered defense and effector-triggered defense is:
  • PAMP-triggered defense is a general defense response against pathogens.
  • Effector-triggered defense is a specific defense response against particular pathogens.

Test Your Knowledge on Plant Growth Regulators and Seed Dormancy