Chapter 29: How plants colonized Land

Question 1

What are 6 traits that plants have in common with protists like algae?

Answer 1

1. Multicellular
2. Eukaryotic
3. Photosynthetic
4. autotrophic
5. cellulose walls
6. chloroplasts with chlorophylls a and b

Question 2

What is the relationship between charophytes and land plants?

Answer 2

Charophytes are the only algae that are the closest relatives to land plants NOTE: ** LAND PLANTS DID NOT EVOLVE FROM CHAROPHYTES**

Question 3

What are 4 distinctive traits that plants and charophytes share? (synapomorphy features with charophytes)

Answer 3

1. Rings of cellulose-synthezising proteins (instead of linear in other algae)
2. Peroxisome enzymes (minimize loss of organic products)
3. Flagellated sperm
4. Formation of Phragmoplast (wall between nuclei of two daughter cells during cell division)

Question 4

What is sporopollenin and why was it useful in adaptation to terrestrial life?

Answer 4

sporopollenin is a layer of durable polymer that prevents exposed zygotes from drying out. It enabled plants to live above the waterline.

Question 5

What are 4 benefits to moving to terrestrial life for plants billions of years ago?

Answer 5

1. bright, unfiltered sunlight
2. more co2 from atmosphere than water
3. soil by the edge of water had tons of nutrients
4. few herbivores and pathogens

Question 6

What were 2 big challenges of terrestrial habitat living?

Answer 6

1. Lack of water

2. Lack of structural support against gravity

Question 7

what are 4 key traits that appeared in land plants and not charophyte algae? (SYMPLEISOMORPHIES OF LAND PLANTS)

Answer 7

1. alternation of generation (including placental transfer cells and embryophytes)
2. walled spores produced in sporangia (sporopollenin)
3. Multicellular Gametangia (archegonia/anthridia)
4. Apical Meristems

Question 8

What are 2 traits (besides the ones not shared with charophytes) that helped plants adapt to terrestrial life?

Answer 8

1. presence of a waxy cuticle to prevent water loss

2. Secondary Compounds to defend against parasites and herbivores

Question 9

What are Bryophytes and what species do they include?

Answer 9

Bryophytes are nonvascular seedless plants, that include liverworts, mosses and hornworts.

Question 10

What is the dominating form of Bryophytes?

Answer 10

Gametophyte form

Question 11

What do bryophytes need in order for fertilization to happen?

Answer 11

They need to be in a moist environment because the sperm has to travel in a water medium to get to the egg

Question 12

What anchors the gametophytes?

Answer 12

Rhizoids

Question 13

What forms as a result of germinating moss spores?

Answer 13

Protenema –> a mass of green, branched and one-cell-thick filaments

Question 14

Describe the Alternation of Generation Cycle for mosses in 10 steps

Answer 14

1. Spores develop into protonema
2. Haploid protenema produce buds
3. Buds divide through mitosis and form 2 Gametangia: male and female
4. The male gametophyte, contains antheridia that make sperm
5. The female gametophyte, contain archegonium that produce eggs
6. Sperm swims to egg
7. fertilization occurs
8. Zygote develops into sporophyte embryo
9. Sporophyte embryo grows a long stalk that emerges from archegonium
10. Sporophyte is nutritionally attached to gametophyte
11. Meiosis occurs
12. Haploid spores in capsule pop out and form protenema.

Question 15

What is the function of foot of the moss sporophyte?

Answer 15

Absorbs nutrients from gametophyte

Question 16

What is the Seta in the moss sporophyte?

Answer 16

It is a stalk that transports nutrients absorbed from the foot to capsules where spores are made

Question 17

What are peristomes in moss?

Answer 17

They are structures that open in dry conditions to get more water and close in moist conditions to keep in more water.

Question 18

What is a type of moss that is used in peat moss? Why is it beneficial?

Answer 18

Sphagnum is a moss found in wet lands that forms peat moss. It inhibits decay of other organisms and often preserves courses. It also can be a source of fuel because it contains 30% of the world’s soil carbon, therefore its a large co2 reservoir.

Question 19

What are 6 properties of seedless vascular plants?

Answer 19

1. flagellated sperm that needs water to reach eggs
2. mainly lives in damp environments
3. sporophytes are not dependent on gametophytes
4. Sporophyte dominant
5. Contains xylem and phloem
6. Contains sporophylls –> spore bearing leaves

Question 20

What is the alternation of generation cycle for ferns (in 6 steps)?

Answer 20

1. Sporangia releases spores (spores are bisexual)
2. Each gametophyte develops an archegonium (female part) and antheridium (male part)
3. Sperm gets released at different times and eggs develop at different times to promote genetic diversity so other sperm can fertilize the eggs
4. Sperm uses flagella to swim to eggs
5. Zygote develops into a new sporophyte –> grows out of the archegonium of parent gametophyte
6. On the underside of sporophyte leaves are sori which are produce spores from sporangia

Question 21

How do seedless vascular plants transport their water and minerals?

Answer 21

Through Xylem (which is composed of dead cells) and tracheas which are tube shaped cells that carry water and minerals from roots.

Question 22

What are water conducting cells strengthened by?

Answer 22

Lignin

Question 23

What are tubes that transport sugars, amino acids and other organic products from the leaves to the rest of the plant in seedless vascular plants?

Answer 23

Phloem

Question 24

What is the difference between microphyll leaves and megaphyll leaves?

Answer 24

Microphyll leaves are older and they are small and spine shaped and are supported by a single strand of vascular tissue
Megaphyll leaves are newly evolved leaves with tons of branching and a vascular system that has a greater photosynthetic productivity

Question 25

How do homospores produce spores in 3 steps?

Answer 25

1. Sporangium on sporophyll
2. Produces single type of spore
3. Typically bisexual gametophytes which make eggs and sperm

Question 26

How do heterospores produce spores in 2 steps?

Answer 26

FEMALES:

1. Megasporangium on megasporophyll
2. Produces megaspores
3. Megaspores produce female gametophyte
4. Female gametophyte produces eggs

MALES:

1. Microsporangium on microsporophyll
2. Produces microspores
3. Microspores produce male gametophyte
4. Male gametophyte produces sperm

Question 27

What are 2 clades of seedless vascular plants?

Answer 27

1. Lycophytes (phylum lycophyta): include club mosses, spike mosses and quill worts
2. Pterophytes (phylum pterophyta): include ferns, horsetails and whisk ferns

Question 28

Whats the difference between lycophytes and pterophytes?

Answer 28

pterophytes are more closely related to seed plants, and have megaphyll leaves and branching roots.
Lycophytes are mostly microphyll leaves and only branch at growing up of root.

Question 29

What is a significance of seedless vascular plants today?

Answer 29

used as coal when they’re fossilized because they store ALOT of Co2.

Question 30

Which prehistoric era did seedless vascular plants dominate the earth? Why?

Answer 30

Carboniferous period –> because there was a lot of co2 in the atmosphere and they stored a lot of it and were able to utilize it.

Question 31

What are 3 advantages of bryophytes not growing tall and being thin?

Answer 31

1. no vascular system –> don’t have something to support their weight or resist gravity
2. Get nutrients straight from the ground
3. Thinness allows them to absorb from atmosphere and ground without need for a transportation system

Question 32

What are 3 Economic uses for seedless vascular plants (like pterophytes and lycophytes)?

Answer 32

1. silicon dioxide on horsetail stems (lycophytes) that are cleaning agents
2. Young fern sporophytes that are called fiddleheads –> edible
3. Spores produced by lycophytes were once used as flash powder in photography because they’re rich in oils