What is a Plant

Question 1

What pigments define green plants

Answer 1

Chlorophyll a and b

Question 2

What is the primary energy reverse in green plants and where is it stored

Answer 2

Starch (α-1,4 glycan), stored in chloroplasts

Question 3

What structural features of chloroplasts enhances light absorption

Answer 3

Stacked thylakoid membranes (grana)

Question 4

What are plant cell walls composed of and what does this provide

Answer 4

Cellulose, providing structural support and rigidity

Question 5

What is unique about the flagella of motile green plant cells

Answer 5

They have a stellate base, distinct from other eukaryotes

Question 6

What are the two main groups within green land plants

Answer 6

Green algae (Chlorophyceae) and land plants (Embryophytes)

Question 7

Which green algae are primarily aquatic

Answer 7

Chlorophyceae

Question 8

Name the major groups of green plants

Answer 8

Bryophytes, Lycophytes, Pterophytes, Gymnosperms, Angiosperms, Seed Plants (Spermatophytes), Spore Plants

Question 9

Which groups reproduce via spores

Answer 9

Bryophytes, Lycophytes, Pterophytes

Question 10

Which groups reproduce via seeds

Answer 10

Gymnosperms and Angiosperms (Spermatophytes)

Question 11

What is the function of the cuticle in land plants

Answer 11

prevents water loss

Question 12

What are the stomata and what do they do

Answer 12

Openings that regulate gas exchange - absent in liverworts

Question 13

What are trilete spores and why are they important

Answer 13

Spores with thick walls of sporopollenin, resistant to desiccation

Question 14

What symbiotic relationship is vital for nutrient uptake in most land plants

Answer 14

Arbuscular mycorrhizas with fungi

Question 15

What are the two types of vascular tissue in plants

Answer 15

Xylem (water, with lignin) and Phloem (nutrients/sugars)

Question 16

What reproductive structure is unique to embryophytes

Answer 16

Archegonia (egg-producing structure)

Question 17

Which groups have lots their archegonia

Answer 17

Gnetales and Angiosperms

Question 18

What is the closest living relative to land plants

Answer 18

Zygnematales (e.g. Spirogyra), based on molecular data

Question 19

Name other Charophyte algae related to land plants

Answer 19

Charales (Chara), Coleochaetales (Coleochaete)

Question 20

What kind of life cycle do land plants have

Answer 20

Haplo-diplontic (Alternation of Generations)

Question 21

How is the life cycle of land plants different charophyte algae

Answer 21

Charophytes have a haplontic life cycle (dominant haploid phase)

Question 22

What is the earliest known complete land plant fossil

Answer 22

Cooksonia (~428 million years ago, Late Silurian)

Question 23

What adaptations are seen in Psilophyton dawsonii

Answer 23

Vascular system with pitted tracheids, leaf-like structures, clustered sporangia

Question 24

What are archegonia and antheridia

Answer 24

the female and male reproductive organs

Question 25

Where does the zygote develop in early land plants

Answer 25

Inside the archegonium

Question 26

How did the sporophyte evolve according to the interpolation theory

Answer 26

The zygote remained in the archegonium, divided mitotically to form a multicellular sporophyte

Question 27

What fossil evidence supports early sporophyte evolution

Answer 27

Cooksonia, Aglaophyton, and Rhynia

Question 28

What trend is seen in sporophyte branching evolution

Answer 28

Equal dichotomy → Unequal dichotomy → Overtopping

Question 29

Why is vascular tissue important in sporophyte branching evolution

Answer 29

Improved water/nutrient transport enabled height and complexity

Question 30

What is lignin and what does it do

Answer 30

A structural compound in xylem - provides strength and waterproofing

Question 31

List 5 types of tracheid wall thickenings

Answer 31

Annular, helical, scalariform, reticulate, pitted

Question 32

What are microphylls and where are they found

Answer 32

Simple, single-veined leaves found in lycophytes

Question 33

What are megaphylls

Answer 33

Complex-veined leaves found in ferns and seed plants

Question 34

What two theories explain leaf evolution

Answer 34

Enation Theory (Bower, 1935): Leaves evolved from surface outgrowths. Telome Theory (Zimmerman, 1952): Flattened branches with webbing.

Question 35

What may have driven leaf evolution

Answer 35

Declining CO₂ levels in the Late Ordovician/Devonian

Question 36

Did true roots evolve once

Answer 36

No, they evolved independently in multiple lineages during the Devonian

Question 37

Define homorhizic roots

Answer 37

A single unipolar stem with adventitious roots

Question 38

Define allorhizic roots

Answer 38

A primary root develops below a shoot-producing stem

Question 39

What evolutionary trends are observed in early vascular plants

Answer 39

1. Increased sporophyte branching and size. 2. Greater vascular complexity. 3. Reduction in gametophyte dominance. 4. Emergence of roots and leaves.

Question 40

What was the dominant stage in early land plants like mosses

Answer 40

Gametophyte

Question 41

What major clade did early branching sporophytes evolve into

Answer 41

Polysporangiate clade

Question 42

What distinguishes microphyllous from megaphyllous plants

Answer 42

Microphylls = simple, single vein (lycophytes); Megaphylls = complex, branched veins (ferns, seed plants)