Diversity Midterm Study Material - Flashcards for Key Concepts in Biology (Chapters 12)

germination is first triggered by...

external stimulus (usually water)

gibberelin

plant hormone that stimulates growth and may cause dramatic increases in size

phytohormones

plant hormones: small molecules that diffuse from meristem to root (discovered by darwin)

gibberelin

hormone that increases size of seed and triggers cells to create a-amylase using gene

gibberellic acid

a plant hormone that causes stem elongation and fruit enlargement

auxin

first hormone discovered, lets plants germinate in the dark (controls plant growth and development across multiple environments)

apical dominance

when the shoot tip has control of the axillary bud outgrowth

cytokinin

adenine-like molecule, shoot induction, axillary bud outgrowth, prevents leaf senescence

leaf senescence

process of aging/growth of leaf

abscisic acid

water stress response, stomate closing, dormancy (closes stoma when water is scarce, stops transpiration)

ethylene

a gas, ripens fruit, causes leaf senescnce, and leaf abscission

phototropin

pigment in plasma membrane that absorbs blue light

phytochrome

red light receptors that help the adaptation of plant growth and development

leaf abscission

Aging and dropping of leaves controlled by auxin and ethylene.

polar transport of auxin

1. found in terminal bud and moves to root

2. uncharged - crosses plasma membrane of a plant cell

3. inside cell, high pH, becomes charged

4. exits on "root end" of cell through eflux carriers