Origins of Land Plants - Lecture 9

Question 1

When did plants first appear on land?

Answer 1

Late Ordovician - Silurian

Question 2

Where were plants found before the early Devonian and give an example of an exceptional preservation

Answer 2

Only in wet areas. Exceptional preservatio - Rhynie Chert in Aberdeenshire

Question 3

Name 4 features of plants before the early Devonian

Answer 3

No leaves (Photosynthesis along green stem), No roots (instead an underground stem), Sporangia (spore bearing capsules) on the tip of branches and permanently confined to wet environments

Question 4

What key evolutionaryt innovations occurred during the late Devonian and what were they used for?

Answer 4

Innovations such as secondary xylem (wood), leaves, roots and seeds. This allowed plants to grow tall and perform more efficient photosynthesis. The seeds allowed forests to form as they were no longer dependent on surface water

Question 5

When did global forestation first occur?

Answer 5

Carboniferous

Question 6

Why are Carboniferous plants important?

Answer 6

Coal, understanding of biodiversity, control of Carboniferous climate and lessons on carbon sequestration

Question 7

Name three Carboniferous spore-bearing plants

Answer 7

Lycopsida (e.g. Lepidodendron), Equisetopsida (e.g. Calamites and Annlaria) and Filicopsids (true ferns)

Question 8

Name two Carboniferous seed-bearing plants

Answer 8

Seed ferns and Conifers

Question 9

Where were peat accumulations found?

Answer 9

In permanently wet environments such as swamps, lake shores and ox-bow lakes

Question 10

What sort of environment are typical of occasionally wet conditions?

Answer 10

Levees, flood plains, point bars and crevase splays