1. Physiology, Reproduction, and Classification
Kingdom Plantae
Physiology, Reproduction, and Classification

2. Plant Hormones
Tropism: the directional movement (growth response) of a plant in response to an environmental stimulus (positive or negative)
Caused by the hormone Auxin
Phototropism: toward a light source
Thigmotropism: to touching a solid object
Gravitropism: directional growth toward/against gravity (roots/stems)
Chemotropism: toward a positive chemical stimulus or away from a negative one

3. Difference between tropism & nastic movement:
Tropism: cell growth due to plant hormone auxin; happens slowly
Nastic movement: due to turgor pressure; happens faster

4. Five additional plant hormones:
Gibberellin
Cytokinins
Abscisic acid
Ethylene: ripens fruit; causes leaves to detach
Florigen

5. Asexual Reproduction Called vegetative reproduction
Formed from stem, roots, or leaves
Grafting: stem or branch
Stolon: stem that runs along ground and forms a new plant
Exact genetic copy

6. Sexual Reproduction in Plants:
Alternation of generations
one generation as haploid gametophyte (n)
one generation as diploid sporophyte (2n)
Nonvascular plants:
gametophyte stage is dominant
Vascular plants
sporophyte stage is dominant

7. Mosses: Sexual Reproduction
Nonvascular
Produce sperm and eggs
antheridium: male gametes
archegonium: female gametes
gametophyte stage is dominant

8. Ferns: Sexual Reproduction
Vascular plants
Sporophyte phase is dominant
Sporophyte grows leaves called fronds
Sporangia: cells that produce spores
Spores released from sori on underside of fronds

9. Gymnosperms: Sexual Reproduction
Diploid sporophyte dominant phase
Produce male and female spores
male (microspores) female (megaspores)
When fertilized the gametophytes form a diploid zygote (the seed)
The seed matures, releases
from cone, lands on ground,
grows into diploid sporophyte

10. Angiosperms: Sexual Reproduction
Flowering plants; flowers are the reproductive organs
vascular plants; sporophyte phase is dominant
Pollen is the male gametophyte
Female gametophyte is contained in the sporophyte

11. Steps for Angiosperm reproduction:
Production of the egg (female) p. 542
Diploid megaspore in ovary undergoes meiosis to form haploid spores; one survives and undergoes mitosis to form 8 haploid nuclei.
Single egg cell formed from one of these.
Production of pollen (male) p. 543
Anther has diploid microspore which undergoes meiosis to form 4 haploid microspores; undergoes mitosis to form 4 sets of 2 haploid spores.
Called pollen
Pollination/Fertilization p. 544

12. Pollination Transfer of pollen from anther to stigma
Pollen grain has tube cell which grows down the style toward ovary.
2 sperm cells travel down tube to ovary
One fertilizes the egg (2n = zygote)
Second sperm cell fuses with polar bodies, forms triploid cell (3n) that becomes the endosperm (nutrition)
Fertilization results in a seed packaged inside fruit (chart on page 546)

13. Germination
Favorable conditions leads seed to break out of seed coat and sprout (grow into new plant)
See page 545

14. Phyla in Kingdom Plantae
chart on page 537 & 548
Nonvascular: >17,000 species
-reproduce with spores
-dominant phase is gametophyte
-no xylem and phloem (small in size)
-moist environment

15. Vascular >255,000 species
-have xylem and phloem
-dominant phase is sporophyte
Seedless:
-reproduce with spores
Seed:
-reproduce with seed (contained in fruit)