Lecture 21

Question 1

Beginning of transition from sea to land

Answer 1

Begins with the microscopic world
Possibly microbial and algal - search for ancient microbes and algae is hampered by low preservation potential on land

Question 2

Common ancestor of all land plants

Answer 2

Green algae - charophytes

Question 3

Earliest evidence of land plants

Answer 3

Crytptospores

Question 4

Disadvantages of plants being in the sea

Answer 4

More grazers (in the beginning)

Question 5

Advantages of plants being in the sea

Answer 5

Neutrally buoyant
Unlimited

Question 6

Disadvantages of plants being on land

Answer 6

Water is a limiting factor: to avoid drying out –> waxy cuticles cover shoots, stems and leaves’ exchange of gases via stomata
Plants need to have structure to be self supporting

Question 7

Advantages of plants being on land

Answer 7

Higher levels of light intensity for photosynthesis
Soils rich in minerals
In the beginning = more space and absence of grazers
New repertoire of reproductive strategies

Question 8

Stomata

Answer 8

Control of CO2 intake vs. evaporation

Question 9

Bryophytes

Answer 9

Mosses

Question 10

What do bryophytes possess?

Answer 10

Waxy cuticle (protective envelope; retains water)
Gamete-producing organs

Question 11

Disadvantage of bryophytes

Answer 11

Need water for reproduction
Depend on humidity of soil and air

Question 12

Bryophytes general morphology

Answer 12

Very simple structures
Simple, root-like hairs for attachment (rhizoids)
No vascular system
Small size

Question 13

Tracheophytes

Answer 13

Vascular plants

Question 14

Root system

Answer 14

Absorption of water and minerals

Question 15

Shoot system

Answer 15

Stems and leaves = aerial network, for the transportation of nutrients
Waxy cuticle limits evaporation

Question 16

Conductive tissue

Answer 16

Transport of vital elements in the plant

Question 17

Tracheophytes general morphology

Answer 17

Relatively complex structures
Less dependent on surrounding environmental conditions
Varying sizes (surrounded by woody cells)

Question 18

When did the first macroscopic land plants appear?

Answer 18

Silurian period

Question 19

First macroscopic land plants

Answer 19

Cooksonia

Question 20

Roots and development of soils

Answer 20

Significant impact on the environment

Question 21

Pteridophytes

Answer 21

Cryptograms
Ferns and relatives

Question 22

Pteridophytes general features

Answer 22

No flowers, no seeds
Reproduce using spores

Question 23

Cluster of sporangia

Answer 23

Sorus

Question 24

Devonian forest

Answer 24

Dominated by horsetails, ferns, lycophytes (clubmosses), pro gymnosperms (extinct group ancestral to conifers and flowering plants)
Early insects and spiders co-evolved with plants
No large herbivores existed

Question 25

Devonian diversity

Answer 25

Diverse life on land and in brackish and fresh water, including trees, fishes, insects, and earliest tetrapods

Question 26

Carboniferous forests

Answer 26

Often wet and swampy

Question 27

Gymnosperms stratigraphic range

Answer 27

Carboniferous-recent

Question 28

Gymnosperm examples

Answer 28

Conifers Gingko

Question 29

Gymnosperm defining feature

Answer 29

No closed compartment protecting the seed during development

Question 30

Angiosperms

Answer 30

Most diverse plants in recent times Often need insects for pollination

Question 31

Cretaceous land life

Answer 31

Dinosaurs, gymnosperms, angiosperms, etc.