7-First Land Plants

Question 1

Bryophytes are…

Answer 1

simplest land plant phyla

Question 2

The three phyla in Bryophytes are:

Answer 2

-Liverworts ~ 5200 spp – Marchantiophyta
– Mosses ~ 10,500 spp – Bryophyta
– Hornworts > 300 spp– Anthocerotophyta

Question 3

Club mosses (Lycopodiophyta) have..

Answer 3

roots & vascular tissue

Question 4

Ferns etc. (Monilophyta) have…

Answer 4

complex leaves

Question 5

Gymnosperms =

Answer 5

leaves ( 4 groups)

Question 6

Angiosperms =

Answer 6

flowers and fruits
1 group= Anthophyta (>300,000 species)

Question 7

Monophyletic =

Answer 7

all of the organisms from a common ancestor

Question 8

Paraphyletic =

Answer 8

organisms descended from a common ancestor, but not including all the descendant groups.

Question 9

Polyphyletic =

Answer 9

do NOT share a common ancestor

Question 10

Convergent Evolution =

Answer 10

Unrelated, but similar in some characteristics (e.g. cactus)

Question 11

Ordovician
(505-440 mya)

Answer 11

Lots of life in the sea, only cyanobacteria and algal mats on land.

Question 12

THREE features developed to cope with the challenges of survival on land

Answer 12

1-Compact, multicellular plant body
2-Cuticle
3-Protected gamete and spore cells

Question 13

All land plants have these THREE things:

Answer 13

1– Spores in sporangia
2– Gametes in gametangia
3– Oogamy = large, non-motile egg & small, motile sperm (oogamous) *capable of motion

Question 14

Early land plants rapidly evolved these FOUR things…

Answer 14

1- larger body size
2- epidermis
3- cuticle
4- stomata
5-and (eventually) vascular tissue

Question 15

What is Class Charophyceae?

Answer 15

-Freshwater green algae
-Most probable ancestors of land plants

Question 16

SIX Shared features of land plants & some Charophyceae (freshwater green algae)

Answer 16

1-Pigments
– Chlorophyll a
– Chlorophyll b and carotenoids
– Phytochrome
2-Chloroplast features:
– well-developed grana
– starch stored in chloroplasts
3-Cell walls containing cellulose
4-Terminal cellulose synthase complex in rosette form
5-Common features of mitosis
– Breakdown of nuclear envelope
– Persistent phragmoplasts
6-Sporopollenin in walls of some cells

Question 17

What does Zygotic meiosis?

Answer 17

Charophyceae (freshwater green algae)

Question 18

What does alternation of generations (sporadic meiosis)?

Answer 18

Land plants
**Land plants added a step to the green algae life cycle (added 2n generation in life cycle)

Question 19

Sporophyte =

Answer 19

spore-bearing plant

Question 20

Gametophyte =

Answer 20

gamete-bearing plant

Question 21

What’s another word for all land plants sharing a COMMON ancestor?

Answer 21

monophyletic

Question 22

Similarities among the bryophytes

Answer 22

1-Small
2-Terrestrial (moist habitats)
3-Thin or no cuticle– Most species have some desiccation tolerance
4-Alternation of multicellular generations
5-Dominant gametophyte (1n)
- No true leaves, stems or roots
– Rhizoids
– No lignified vascular tissue
– No stomata
6-Depend on water for sexual reproduction.
7-Gametangia
– surrounded by jacket cells
– Microgametangia =antherida contain sperm
– Megagametangia =archegonia contain eggs
8Oogamous
– Large, non-motile egg
– Small, motile (bi-flagellate) sperm

Question 23

Microgametangia =

Answer 23

antherida contain sperm

Question 24

Megagametangia =

Answer 24

archegonia contain eggs

Question 25

Syngamy =

Answer 25

fertilization; forms a 2n zygote

Question 26

In contrast with charophyte algae…

Answer 26

1-Bryophyte 2n zygote then embryo develop on the gametophyte

2-Bryophyte embryo develops into a multicellular 2n sporophyte

Question 27

In liverworts & mosses:

Answer 27

• Venter encloses an egg cell
• Sperm swim to egg via neck