Chapter 1 Flashcards
(30 cards)
Plants moving in response to light
Phototropism
Plants moving in response to touch
Thigmotropism
Plants moving in response to gravity
Gravitropism
Plants dropping parts in response to environmental cues
Abscission
A temporary state of a lack of plant growth
Dormancy
List the uses plants have for humans
-food
-shelter
-clothing
-purify air
-beauty
-stress reduction
-pharmaceuticals/medicine
-fuel
-prevent erosion/provide habitat
-purify water
When a seed’s embryo is alive and capable of germination
Viable
Ripened ovule
Seed
What a seed consists of
-embryo
-stored food reserves
-seed coat/covering
Requirements for germination
-seed is viable
-proper environmental conditions (water/temp/oxygen/light)
-primary dormancy is overcome
Plant hormone that stimulates germination
Gibberellins (GA)
Plant hormone that inhibits germination
Abscisic acid (ABA)
3 stages of seed germination
- Uptake of water
- Formation of enzyme systems
- Breakdown of storage for energy and building blocks
Green pigment inside of chloroplasts that performs photosynthesis
Chlorophyll
Positive effects of thigmotropism
-plants become short and sturdy to withstand stress from wind or being walked on
-resistance to drought and pathogens
Negative effects of thigmotropism
-inhibit leaf expansion
-decreases photosynthesis
-promotes yellowing leaves
-delays flowering
When a plant bends up against gravity
Negative gravitropism
When a plant bends down with gravity
Positive gravitropism
Describes how plants perceive gravity by statoliths falling to the bottom of cells
Statolith Theory
Amyloplasts in cells thought to play a part in gravity sensing
Statoliths
Categories of dormancy
- Quiescence
- Rest
Dormancy caused by a lack of necessary external environmental factors
Quiescence
Dormancy caused due to internal limitations, regardless of favorable external conditions
Rest
General failure of synthesis reactions
Comes before cell death
Characterized mainly by chlorophyll degradation (browning)
A form of aging
Senescence
