CLEP Bio-Plants

C3 plants

over 95% of species

use enzyme rubisco make 3-carbon compound (during carbon fixation)

loss of carbon through photorespiration is high

requires lower light levels

C4 plants

grasses, sugar cane, maize

extremely low rate of carbon loss through photorespiration

use water efficiently

Alternation of Generation

Mature sporophyte

Meiosis-spores

Mitosis-prothallus (gametophyte)

Mitosis-Gametes

Fertilization-developing sporophyte

Bryophytes

Their dominant state is the gametophyte, meaning that they are normally in the haploid state, not fertilized

Auxins

Main role:

Cell elongation (growth)

Key effects:

Promote stem elongation

Control phototropism (growth toward light) and gravitropism

Maintain apical dominance (main central stem grows more than side stems

Difference between auxins and gibberellins

Auxins: directional growth control

(Tell plant where and how to grow)

(Example: bending toward light)

Gibberellins: growth booster

(Tell the plant grow bigger/taller/faster)

(Example: seeds sprouting, stems shooting up)

Auxins SIMPLE DEFINTION

Cell elongation, promotes growth, phototropism control

Gibberellins SIMPLE DEFINITION

Stem growth, germination, promotes growth, break seed dormancy

Cytokinins SIMPLE DEFINITION

Cell division, promotes growth, delays aging

Abscisic acid SIMPLE DEFINITION

Stress, dormancy, inhibits growth, drought response

(ABA is the “stress hormone” of plants - it slows things down and protects the plant when conditions are unfavorable

Ethylene SIMPLE DEFINITION

Fruit ripening, promotes/inhibits growth, only gaseous hormone

Dicots

1) oaks, flowers, vegetables

2) two cotyledons in seed

3) leaves have branched or networked veins

4) vascular bundles (collections of xylem and phloem tubes) arranged in rings

5) taproot system with smaller secondary roots

6) flowers with petals in multiples of four or five

Monocots

1) grasses, lilies, palm trees

2) one cotyledon in seed

3) leaves have parallel veins

4) stems have random arrangement of vascular bundles

5) fibrous roots

6) flowers with petals in multiples of three