Chapter 31 reading

Question 1

what are the closest living relatives of plants?

Answer 1

green algae, plants evolved differently to survive in air

Question 2

what are the 4 major transformations to plants?

Answer 2

1. Alteration of generations
2. Evolution of xylem & phloem in the sporophyte generation
3. evolution of seeds & pollen
4. Evolution of flowering plants

Question 3

explain how alteration of generations differs plants from algae

Answer 3

every plant species alternates between two multicellular forms: a haploid gametophyte generation that makes gametes and a diploid sporophyte generation that makes spores

Question 4

what does the xylem do?

Answer 4

transports water and dissolved nutrients

Question 5

what does the phloem do?

Answer 5

transports carbs produced by photosynthesis

Question 6

what is the advantage of xylem and phloem?

Answer 6

can transport over greater differences than by diffusion, xylem allows vascular plants to pull water from the soil

Question 7

what did evolution of seeds and pollen allow plants to do better than algae?

Answer 7

fertilization can now take place without releasing swimming sperm into environment. increased probability of next sporophyte generation establishing successfully

Question 8

What are features unique to flowering plants (angiosperms)?

Answer 8

flowers, carpels, double fertilization leading to endosperm, xylem vessels, fruits

Question 9

how long ago did angiosperms evolve? and land plants?

Answer 9

angiosperms - 140 million years old
land plants - 465 million years old

Question 10

how did angiosperms affect other plant life?

Answer 10

outcompeted other types of plants but also diversified life by increasing no. of species that can coexist (they were necessary for formation of modern-day tropical forests)

Question 11

What are the 3 types of Bryophytes?

Answer 11

Liverworts, mosses, hornworts

Question 12

what are characteristics of Bryophytes?

Answer 12

dependence on surface water for hydration and life cycle dominated by a persistent, photosynthetic gamete, no xylem or phloem, small and tough (<5cm tall), some species have a thallus (flattened photosynthetic structure)

Question 13

how many different species of Bryophytes are there?

Answer 13

15,000

Question 14

what are provisions for reproduction in bryophytes?

Answer 14

only haploid gametophyte is free-living, sporophyte attached to and dependent on gametophyte

Question 15

What types of bryophytes have a thallus?

Answer 15

none in mosses, some in liverworts, all hornworts

Question 16

how do bryophytes absorb adn restrict water?

Answer 16

from moisture or rainfall, by surface tension
restrict by a cuticle

Question 17

what are some places bryophytes can grow?

Answer 17

can grow on rock surfaces, branchs of trunks or trees (due to lack of need fro roots) however poor competitors for light

Question 18

How do Bryophytes exhibit cases of Convergent evolution with vascular plants?

Answer 18

-some mosses depend on insects to trasnport spores
-cells specialised for the internal transport of carbohydrates and water i some of the largest mosses and leafy liverworts
-stomata are present on the sporophytes of hornworts and some mosses, particularly in places where a waxy cuticle also develops

Question 19

How does sphagnum moss play an important role in the carbon cycle?

Answer 19

through peat bogs

Question 20

what is a peat bog?

Answer 20

in the wetlands where dead organic matter accumulates rather than decomposes.

Question 21

what do sphagnum moss do in a peat bog? and how?

Answer 21

a key role in creating the wet and acidic conditions that slow rates of decomposition
specialised cells hold onto water and secrete protons that acidify surrounding water and produce phenols slowly decomposing under waterlogged conditions

Question 22

what is significance of peat bog total size and then total carbon impact?

Answer 22

only 2-3% of earths land surface peat bogs but contains 65% that of total greenhouse gas combustion produces per year

Question 23

what do changes in temperature cause for peat bogs?

Answer 23

changes in the water table effect meaning peat bogs are releasing more CO2

Question 24

What are the two groups of spore dispersing vascular plants?

Answer 24

Lycophytes (+ ferns and horsetails)
Gymnosperms and angiosperms

Question 25

WHat are Lycophytes?

Answer 25

disperse by spores and rely on swimming sperm for fertilization

Question 26

What are Gymnosperms and angiosperms?

Answer 26

seed plants, disperse seeds and rely on the aerial transport of pollen for fertilization

Question 27

What allows fo runderstanding of evolution of early vascular plants?

Answer 27

Rhynie chert fossils

Question 28

what are some characteristics of early vascular plants?

Answer 28

small <15cm tall
consist of photosynthetic stems and branched, forming sporangia tips
no leaves
roots extended along ground surface
stems had cuticle with stomata
branched sporophyte contained lignified cell walls but no vascular tissues

Question 29

what does rhynie chert fossils show abot Lycophytes?

Answer 29

evolved leaves and roots independently of all other vascular plants

Question 30

how many lycophyte species today?

Answer 30

1200

Question 31

How did Lycophytes form large trees?

Answer 31

convergent evolution of vascular cambium and cork cambium, 40m tall trees dominated swamps