Lecture 6 - Evolving plants

Question 1

Fungi that are associated with plant roots

Answer 1

Mycorrhiza gives the plant nutrients and the plant gives the fungus sugar

Symbiotic relationships are very useful for for plant growth as lots of nutrients are needed for growth

Question 2

Locopodiophyta

Answer 2

Reproduce by Spores and have an alternation of generations

The sporophyte is dominant and has simple “leaves” - (microphylls) so it is photosynthetic

The plant has a vascular system: xylem

Question 3

Lycophytes

Answer 3

Had both primary and secondary growth: apical growth and lateral growth

These also evolved to have thick stems lined with lignin

Question 4

Carboniferous rainforest collapse

Answer 4

The mass extinction event that was seemingly caused by a huge drop in carbon dioxide levels in the atmosphere

Caused megaphylls to be prevalent

Question 5

Megaphylls

Answer 5

Megaphylls had large leaves meaning that they had a wider area to catch the light and carbon dioxide needed to live.

Since there was limited carbon dioxide in the atmosphere, megaphylls were better equipped for this environment and the evolution of ferns began.

Question 6

Rhynie Chert

Answer 6

Showed the first species to have the sporophyte as the dominant phase

Also showed the first plants to contain vascular tissue

Question 7

Pteridophyta (a type of fern): the one extant Genus

Answer 7

Horsetail (Equisetum)

Question 8

Equisetum innovations

Answer 8

Ring of xylem: better water transport and branching
Rhizomes: extensive roots for better water uptake, also deciduous
Strobili: cone structure that produces spores

Question 9

Carboniferous

Answer 9

300-360 million years ago

Formation of Pangaea

Bigger arthropods due to more oxygen and bigger land plants

Lots of carbon deposits at this stage (coal, limestone, oil)