Introduction to Plants (Chp. 24)
I.
II.
Plant Adaptations
a. Plants on Land
i. Absorbing nutrients
1. mycorrhiza
ii. Preventing water loss
1. cuticle- a waxy layer that covers the non-woody above ground parts of most
plants (reduces water loss)
2. Stomata- pores that permit plants to exchange oxygen and carbon dioxide.
3. Guard Cells- specialized cells that border the stomata
iii. Reproduction on land
1. pollen- carry sperm outside of water and keep sperm from drying out
b. How did plants succeed
i. Vascular system- well-developed vascular tissues that distribute materials efficiently.
1. vascular plants-plants with a vascular system
2. nonvascular plants-small plants that lack a vascular system
ii. Seeds- a structure that contains the embryo of a plant
1. embryo- an early stage in the development of plants and animals
2. Advantages that seed plants havea. Protection of seeds
b. Nourishment to the seed
c. Plant dispersal
d. Delayed growth
iii. Flowers- reproductive structure that produces pollen and seeds
1. attract animals, such as insects, bats and birds
a. allows for cross pollination over great distances
2. designed to catch pollen blown by wind
iv. Alternation of generations- (see fig. 24-6)
1. In the life cycle of a plant, a haploid (n) gametophyte generation alternates with a
diploid (2n) sporophyte generation.
2. Sporophyte generation has a vascular system consisting of 2 types of tissue.
a. Phloem-consists of relatively soft-walled cells that transport organic
nutrients
b. Xylem-Hard walled cells that transport water and mineral nutrients
Kinds of Plants
a. Nonvascular plants
i. Small
ii. Gametophyte is larger
iii. Sporophyte grow on top of gametophyte
b. Seedless Vascular plants
i. Vascular system
ii. Sporophyte is larger
iii. Gametophyte grow on top of sporophyte
c. Gymnosperms (naked seed) -seed plants that produce cones
i. Produce seeds
ii. Reduced gametophytes
iii. Wind pollination
iv. Examples:
1. pine trees
2. palm trees
3. ginkgo
d. Angiosperms
i. Flowers
ii. Fruits- structures where seeds develop
iii. Endosperm-supply of stored food in angiosperms for seeds
iv. Kinds:
1. Monocots-flowering plants that produce seeds with one seed leaf (grass)
2. Dicots- flowering plants that produce seeds with two seed leaves. (Roses)
III.
Plants in our lives
a. Fruits and Vegetables
i. Vegetative part is the nonreproductive part
b. Root Crops (potatoes)
c. Legumes (beans, peanuts and peas are seeds of legumes)
d. Cereals (Wheat, corn, rice)
e. Nonfood (wood, Medicines, Fibers)