17 - Plants: Life on Land

Question 1

What is the common ancestor of all land plants?

Answer 1

The Chara species of algae.

Question 2

What are the 4 derived characteristics of land plants?

Answer 2

1. Alternation of generations
2. Multicellular dependent embryos
3. Multicellular organs that produce egg and sperm
4. Apical meristems

Question 3

What challenges did plant life on land face?

Answer 3

1. How to obtain/retain water
2. How to bring gametes together
3. Seed dispersal
4. Obtaining nutrients

Question 4

What plants do bryophytes and tracheophytes contain? What stages are dominant (sporophyte or gametophyte)?

Answer 4

Bryophytes (Hornworts, Liverworts, Mosses) have a dominant gametophyte generation.
Tracheophytes (ferns, gymnosperms, angiosperms) have a dominant sporophyte generation.

Question 5

How have bryophytes adapted?

Answer 5

Only one gamete needs to venture out, partial waxy cuticle, stomata.

Question 6

How have tracheophytes adapted?

Answer 6

Vascular system, proper roots, lignin in cell walls, advanced stomata, full waxy cuticle.

Question 7

What is the significance of the seed?

Answer 7

Hardy casing with food reserves for the developing plant within. Increases chances of survival and well adapted for dispersal.

Question 8

What is the significance of pollen?

Answer 8

Pollen removes the need for fluid continuity between male and female parts.