Plant Life Cycle

Question 1

Plant life cycle

Answer 1

Has separate multicellular haploid and diploid stages that alternate = the alternation of generations

Question 2

Sporophyte

Answer 2

multicellular diploid stage, produces haploid spores by meiosis (2N)

Question 3

Gametophyte

Answer 3

multicellular haploid stage produces haploid gametes by mitosis (N)

Question 4

Rhizome

Answer 4

Horizontal stem

Question 5

Fiddlehead

Answer 5

Young, coiled-up leaf

Question 6

Sporangia

Answer 6

1. Produce spores

2. Disperse the spores

Question 7

Anatomy of Sporangium

Answer 7

Capsule: where the spores are made, has 3 cell types
1. Jacket cells - protection (2N)
2. Annulus - ridge of dead water filled cells, thick inner wall, thin outer walls. (mohawk)
3. Lip Cells - below the annulus, fragile cell walls (2N)
Stalk - holds up the capsule and attaches it to the leaf

Inside: 2 cell types

1. Tapetum - 2 layers of nutritive cells
2. Spore mother cells (2N) - undergo meiosis to promote spores

Question 8

Spore

Answer 8

• Single cell w/ haploid nucleus
• Contains storage granules: proteins, lipids, carbs
• Thick protective spore coat w/ an outer layer of sporopollenin
• Trilete scar: thin spot in spore coat, proximal pole

Question 9

Spore Release

Answer 9

1. Sporangium jacket & annulus cells lose H2O
2. Thin outer walls of annulus shrink more than thick inner walls
3. Rise in tension in annulus
4. Lip cells tear –> open sporangium
5. Annulus peels back & flips forward, dispersing the spores