Lecture 5: Greening of the Earth

Question 1

Are plants eukaryotes or prokaryotes?

Answer 1

eukaryotes

Question 2

What are some characteristics of plants?

Answer 2

They are multicellular, photoautotrophs, and they have cell walls made of cellulose

Question 3

What other “thing” has the same traits as the plant(multicellular, cell wall made of cellulose, and a photoautotroph)?

Answer 3

Seaweed, a protist has all these traits as well

Question 4

What are some differences between plants vs protist differences?

Answer 4

• all plants multicellular: algae can be unicellular, colonial, or multicellular
• most plants live on dry land, algae live in aquatic or moist habitats
• plants have a waxy cuticle, algae does not
• most plants have roots, stems, leaves, and vascular tissue, algae does not

Question 5

What is a charophyte?

Answer 5

green algae that is a protist

Question 6

what are the basic resources plants require in order to survive and reproduce?

Answer 6

water, light, and co2 for photosynthesis, o2 for cellular respiration, mineral nutrients to make dna, proteins, lipids(nitrogen, phosphorous, potassium)

Question 7

The transition from living in water to living on land provided both benefits and challenges for plants in terms of?

Answer 7

support, resources, and reproduction

Question 8

What are some benefits for algae to live in water?

Answer 8

• surrounded and supported by water
• access to lights
• can take up nutrients directly from water via diffusion
• gametes released directly into water for easy dispersal
• stable temperatures and humidity

Question 9

What are some limitations for algae to live in water?

Answer 9

• can only access light near surface
• there are limited amounts of dissolved o2, co2, and minerals

Question 10

What are some benefits for the first plants to live on land?

Answer 10

• brighter, unfiltered sunlight
• plenty of co2 and o2
• soil rich in nutrients
• the first land plants had less competition and fewer predators

Question 11

What are some limitations for the first plants to live on land?

Answer 11

• Lack of structural support against gravity
• Lack of water - as a resource and to stop
  from drying out ( desiccation )
• Fluctuating temperature & humidity
• Nutrients and water need to be
  transported from soil to plant
• Modes of reproduction needed to be altered ( to prevent spores from drying out, and for dispersal )

Question 12

What are derived traits?

Answer 12

unique traits that evolved during the evolution of a specific lineage after the split from the common ancestor with other lineages

Question 13

What do the derived traits of plants distinguish them from?

Answer 13

close green algae relatives, charophytes

Question 14

5 derived traits found in all plants but not protists are?

Answer 14

1. Alternation of generations
2. Embryophytes
3. Walled spores made in sporangia
4. Multicellular gametangia
5. Apical meristems

Question 15

Alternation of generations?

Answer 15

plant life cycles alternate between gametophyte
(gamete-producing plant) and sporophyte (spore-producing plant): both are multicellular

Question 16

Embryophytes?

Answer 16

a multicellular plant embryo dependent on the parent
* The developing embryo remains inside the tissues of the female plant
* Get protection and nutrients via specialized placental transfer cells

Question 17

Walled spores made in sporangia?

Answer 17

sporangia: multicellular organ with the sporophyte plant that produces spores
spores: single reproductive cells that grow into the multicellular gametophyte

Question 18

What are spore walls made of?

Answer 18

sporopollenin: making the spores extremely resistant to harsh environments

Question 19

Multicellular gametangia?

Answer 19

• Gametangia: multicellular organ within the gametophyte that produces gametes
  Female gametangia: archegonia make eggs and male gametangia: antheridia makes sperm

Question 20

What is phyte?

Answer 20

plant

Question 21

Spore/gamete?

Answer 21

reproductive cells

Question 22

Gametophyte?

Answer 22

plant that produces gametes

Question 23

Sporophyte?

Answer 23

plant that produces spores

Question 24

embryo?

Answer 24

developing organism after fertilization

Question 25

embryophyte?

Answer 25

developing plant

Question 26

angium?

Answer 26

receptacle/container/organ

Question 27

gametangia?

Answer 27

organs that make gametes

Question 28

sporangia?

Answer 28

organs that make spores

Question 29

apical meristems?

Answer 29

areas of cell division at the tips of roots and shoots: plants on land need resources from above ground and below ground, therefore need to grow up and down

Question 30

what does plant meiosis form?

Answer 30

spores

Question 31

are gametes formed before or after fertilization?

Answer 31

before

Question 32

what does the archegonia make?

Answer 32

eggs

Question 33

evolution of plants?

Answer 33

as plants continued to adapt for successful life on land, new derived traits emerged. Key adaptation = a notable derived trait that provides an individual with a new ability that allows it to take advantage of previously unavailable habitats or resources

Question 34

early evolving plant groups:

Answer 34

fewer adaptations and are more similar to aquatic algae than later groups

Question 35

later evolving groups:

Answer 35

retain all the key adaptations that arose in earlier groups

Question 36

byrophytes?

Answer 36

the first land plants are non vascular:including liverworts, mosses and hornworts

Question 37

what are the key adaptations to these non vascular plants?

Answer 37

waxy cuticles: coats the surface of the plant to prevent water loss/drying out stomata: pores in the surface that open and close: exchange of co2 and o2 with surrounding air, where water evaporates, close to minimize water loss

Question 38

what are the byrophytes major limitations?

Answer 38

height is below 20cm, no vascular system or true roots or leaves no long distance transport of water and nutrients limited structural support restricted to moist environments dispersal by spores: small short distances

Question 39

vascular plants?

Answer 39

have vascular tissue; systems of tubes that transport water and nutrients throughout the organism.

Question 40

seedless vascular plants include?

Answer 40

ferns, horsetails, club mosses

Question 41

what are the two vascular tissues?

Answer 41

xylem and phloem: transport tissues connecting above and below ground and move water and nutrients long distances; the secondary cell walls of xylem also provide support against gravity

Question 42

leaves?

Answer 42

main photosynthetic organ : increase surface area for light capture

Question 43

roots?

Answer 43

structures that extend into soil : increase access to water and nutrients in soil, anchor the plant

Question 44

seedless vascular plants limitations?

Answer 44

- limited to moist environments bc they need film of water for reproduction, spores= limited dispersal