Chapter 14 Flashcards
Physiology
The study of how an organism or any one of its parts functions.
Germination
The process by which a seed develops into a seedling.
Photoperiodism
The response of an organism to seasonal changes in day length.
Annual
A plant that lives for one growing season.
Abscission
A process in which the plant seals off its connection to a leaf, causing the leaf to die and fall off.
Quiescence
A short-term resting state in seeds where growth of the embryo is suspended.
Senescence: The process of aging that leads to death.
Senescence
The process of aging that leads to death.
Apical dominance
The influence of the shoot tip to inhibit the growth of lateral buds, reducing branching.
Does transpiration increase? How does it affect water/mineral flow in xylem?
Yes. When transpiration increases (due to open stomata), it pulls water upward through the xylem via cohesion and adhesion, helping move water and dissolved minerals from roots to leaves.
How is nitrate formed in soil? What makes it usable?
Nitrogen-fixing bacteria convert nitrogen gas (N₂) into ammonium (NH₄⁺), then into nitrite (NO₂⁻), and finally into nitrate (NO₃⁻), which is usable by plants.
Pollination in flowering plants
Pollination is the transfer of pollen from the male stamen to the female pistil. It initiates the fertilization process.
Tropism: What determines which direction a plant grows?
Plant growth direction is determined by tropisms—growth responses to environmental stimuli:
Phototropism – response to light
Gravitropism – response to gravity
Thigmotropism – response to touch
What are the 3 major categories of phytohormones?
Grouped by primary function:
1. Auxins – cell elongation, apical dominance, fruit formation
2. Gibberellins – growth, stem elongation
3. Cytokinins – cell division, delay of senescence
(Also important: Ethylene – ripening, abscission; Abscisic Acid – dormancy, stress responses)
