Lecture 8: plant diversity I

Question 1

Where did land plants evolve from

Answer 1

ancestral charophytes

Question 2

who are the sister taxa to land plants

Answer 2

modern charophytes

Question 3

adaptations of charophytes

Answer 3

• live at edges of ponds

- sometimes dries out -> selection favors survival on dry land

Question 4

what are the derived traits of charophytes

Answer 4

• sporopollenin: layer of polymer, surrounds zygote, prevents desiccation
• structure of flaggellated sperm
• cell plate
• rings of cellulizing - synthesizing protiens

Question 5

derived traits of land plants

Answer 5

• 2 multicellular life stages
• multicellualr, dependent embryo
• walled spores: produced in sporangia
• multicellular gametangia
• apical meristems
• cuticle
• stomata

Question 6

haploid gametophyte

Answer 6

• produces gametes by mitosis

Question 7

haploid sporophyte

Answer 7

• produces spores by meisosis

Question 8

multicelullar, dependent embryo

Answer 8

• 2n embryo retained within tissue of female gametophyte
• nutrients transferred from parent
• land plants called embryophytes

Question 9

walled spores produced in sporangia

Answer 9

• sporangia
• sporocytes
• spores
• spore wall contains sporopollenin
• resistant to harsh conditions

Question 10

sporangia

Answer 10

• multicellualr organs that produce spores (2n)

Question 11

sporocytes

Answer 11

• diploid cells, undergo meiosis -> haploid spores

Question 12

spores

Answer 12

haploid reproductive cells (n)

- mitosis-> multicellular gametopyte

Question 13

multicellular gametangia

Answer 13

• multicellular gamete- producing organ - 2 types (archegonia, antheridia)
• haploid by mitosis

Question 14

archegonia

Answer 14

female, produces eggs, sites of fertilization

Question 15

antheridia

Answer 15

male, produce and release sperm

Question 16

apical meristems

Answer 16

• plnats dont move, they enlogate
• regions of cell divisions at tips of roots and shoots
• cell differentiate from apical meristems

Question 17

cuticle

Answer 17

• waxy covering ocel all above-ground parts
• prevents desiccation
• provides some protection from microbes
• does not all for gas exchange

Question 18

stromata ( singular- stroma)

Answer 18

• tiny openings on surface
• can open and close
• allow gas exchange
• allow water evaporation

Question 19

classification of land plants

Answer 19

vascular tissue

Question 20

vascular tissue

Answer 20

• cell joined into tubes - transport water and nutrients

- can group extant plants based on vascular tissue

Question 21

non vascular plants

Answer 21

• basal plants
  -bryophytes: mosses and relatives
  lack specilaized vascuale systems
• paraphyletic

Question 22

vascular plants

Answer 22

• seedless and seed plants
• seedless vascualr plants: basal vascular plants
  
  • ferns and related plants
  • basal vascualr plants
  • paraphyletic

Question 23

seed plants

Answer 23

seed: embryo with supply of nutrients with protective coat

- majority of extant species - 2 groups : gymnoperms & angiosperms

Question 24

gymnosperms

Answer 24

• naked seed
• seeds not enclosed in chamber
• ex: conifers

Question 25

angiosperms

Answer 25

- container seed - flowering plants - send enclosed in fruit - most dominant type of plant

Question 26

moss life cycle

Answer 26

1. spores (n) : suitable habitat -> germinate -> mitotic growth -> protonema (filament of cell) 2. gametophyte 3. fertilization 4. sporophyte 5. sporangium

Question 27

protonema

Answer 27

- forms buds that divide by mitosis -> gametophores

Question 28

gametophyte

Answer 28

- gametophyte gen is dominant - can live independently of sporophyte - rhizoids - anchor gametophyte, not roots

Question 29

fertilzation

Answer 29

- flagellated sperm ( swim through film of water towards eggs archegonia) - sperm fuses with egg -> zygote (2n) - zygote - stays in archegonium, - mitotic growth -> multicellular embryo ( 2n)

Question 30

sporangium

Answer 30

spore- producing structure

Question 31

importance of moss

Answer 31

- extremely common - can colonize bare, sandy soil - sometimes harbor N- fixing bacteria - important fuel source

Question 32

vascular plants derived traits

Answer 32

1. sporophyte dominant 2. transport in vascualr tissue: have lignin 3. roots 4. leaves 5. sporophylls

Question 33

sporophyte dominant

Answer 33

larger, independent

Question 34

lignin

Answer 34

- polymer in cell walls of water conducting cells - enables tall growth - outcompete shorter plants for light, beter spore dispersal

Question 35

roots

Answer 35

- organs that absorb water and nutrients from soil, anchor plants, allow for taller growth

Question 36

leaves

Answer 36

1 degree photosynthetic organs. increase surface area

Question 37

sporophylls

Answer 37

modified leaves with sporangia, - very diverse, ferns - sori, gymnosperms - cones

Question 38

spore variations

Answer 38

2 forms of spore production - homosporous - heterosporus

Question 39

homosporous

Answer 39

- 1 type of sporangium & spore - most seedless vascular plants - spore grows into bisexual gametophyte

Question 40

heterosporous

Answer 40

- 2 types of sporangia & spores

Question 41

classification of seedless vascular plants

Answer 41

- paraphyletic - ferns ( moniophytes) and related plants - fern life cycle