Plants

Question 1

Introduction

Answer 1

More than 390,000 species on Earth that range in size from 1 mm across to 100 m tall

Question 2

Evolution

Answer 2

Land plants (including sea grasses) evolved from a certain green algae (a protist) called charophytes between 425 - 490 million years ago

Question 3

Evidence of Evolution

Answer 3

Charophytes and plants today both have chlorophyll, cell walls made of cellulose, cell plate formation in mitosis, and the ability to store excess food as starch

Question 4

Characteristics

Answer 4

1. Eukaryotic
2. Multicellular
3. Carry out photosynthesis (autotrophic)
4. Most are terrestrial
5. Cell walls composed primarily of cellulose
6. Sessile

Question 5

Main Groups of Land Plants

Answer 5

Bryophytes, Pteridophytes, Gymnosperms, Angiosperms

Question 6

Bryophytes

Answer 6

No seeds (use spores for reproduction), no vascular tissue (grow low to ground), and no flowers. Very dependent on water to complete life cycle –> sperm must swim from male organ to female organ (ex. mosses, liverworts)

Question 7

Pteridophytes

Answer 7

No seeds (spores for reproduction), has vascular tissue, and no flowers. Developed first symbiotic mycorrhizal relationships (between roots and fungi) to obtain water and other nutrients from the soil (ex. ferns, horsetails)

Question 8

Gymnosperms

Answer 8

Has seeds (naked), has vascular tissue, and no flowers. Male pollen fertilizes ovules in female cone, producing zygote/embryo (ex. coniferous trees - pine, spruce, cedar)

Question 9

Angiosperms

Answer 9

Has seeds (enclosed by fruit), has vascular tissue, and has flowers. Seed enclosed in an ovary, which becomes fruit to protect and nourish (ex. flowering plants - roses, maple trees, fruit trees, etc.)