Campbell: Plant Diversity I: How Plants Colonized Land

Front 1

How many plant species are there?

Back 1

>280k

Front 2

What are the four main groups of land plants and examples?

Back 2

bryophytes (mosses), pteridophytes (ferns), gymnosperms (pines) and angiosperms (flowers)

Front 3

What are the divisions of land plants?

Back 3

Vascular plants include pteridophytes, gymnosperms and angiosperms, while seed plants include just gymnosperms and angiosperms.

Front 4

What characteristics alone fail to distinguish plants from certain algae?

Back 4

Plants and some algae are multicellular, eukaryotic, photosynthetic autotrophs with cellulose cell walls and chlorophyll a and b.

Front 5

What two cellular features do only charophyceans and plants have?

Back 5

rosette cellulose-synthesizing complexes and enzymes within peroxisomes

Front 6

What two derived homologies put charophyceans and plants together?

Back 6

similar flagellated sperm and the formation of a phragmoplast (cytoskeleton and vesicles line up) when new cell walls are formed during cytokinesis

Front 7

What are five characteristics of plants but not charophyceans?

Back 7

apical meristems, dependent multicellular embryoes, alternation of generations, different spores, and multicellular gametangia

Front 8

What are apical meristems?

Back 8

regions of cell division near the ends of shoots and roots, making all sorts of plant cells

Front 9

Why are land plants called embryophytes?

Back 9

Plant embryos and maternal tissue have a boundary of placental transfer cells, through which nutrients are transferred to the embryo.

Front 10

What are the two generations in alternation of generations called, and what do they do?

Back 10

Haploid is gametophyte, the dominant generation in bryophytes, making gametes, that fertilize each other.
Diploid is sporophyte, dominant in all but bryophytes, using meiosis to make spores.

Front 11

What two traits involving spores separate plants from charophyceans?

Back 11

Plant spore cell walls have the durable polymer sporopollenin, and multicellular sporangia protect the spores before they are ready to be released.

Front 12

Where do plant gametophytes make their gametes?

Back 12

It all happens in multicellular gametangia organs, with a single egg being made within each female gametangium, or archegonium, and a bunch of sperm made in each male gametangium, or antheridium.

Front 13

What are three terrestial adaptations made by plants?

Back 13

A waxy cuticle protects against water loss and microbes, with stomata to exchange gases though. Xylem and phloem transport water throughout plants. Secondary compounds made off the main anabolic pathways do a variety of things.

Front 14

What are some examples of secondary compounds and their uses in plants?

Back 14

Alkaloids, terpenes and tannins defend land plants against herbivores, flavanoids absorb UV, phenolics combat pathogens and solidify structure.

Front 15

How many years ago did plants invade the land?

Back 15

fossils say >500M, with the oldest in 550M Cambrian rocks, and there are lots of spores at 460M, indicating they were widespread by then

Front 16

What two charophyceans are most closely related to plants?

Back 16

Chara and Coleochaete

Front 17

How is alternation of generations hypothesized to arise?

Back 17

through a delay before meiosis, since the closest charophyceans are haploid

Front 18

Where is sporopollenin hypothesized to arise?

Back 18

in shallow water

Front 19

What is "deep green"?

Back 19

an international initiative trying to establish the monophyletic clades of plants

Front 20

What are the three potential plant kingdoms?

Back 20

Plantae, which has land plants, Streptophyta, which includes charophyceans and land plants, and Viridiplantae, which has chlorophytes, charophyceans, and land plants

Front 21

What are the three phyla of bryophytes and their common names?

Back 21

Hepatophyta (liverworts), Anthocerophyta (hornworts), and Bryophyta (mosses)

Front 22

What are four "mosses" that aren't bryophytes?

Back 22

Irish moss (red seaweed), reindeer moss (lichen), club mosses (pteridophytes), and Spanish moss (flowering plant)

Front 23

What are protonemata and what do they do?

Back 23

masses of green cell-thick filaments made from germinating moss spores that absorb water/minerals and make meristems and mature gametophores

Front 24

What do bryophyte tissues lack that makes them nonvascular plants and limits their height?

Back 24

lignin

Front 25

What are rhizoids and what do they do?

Back 25

long clear cells or filaments that hold bryophytes down

Front 26

Describe a moss sporophyte.

Back 26

Its foot gets nutrients and food from the parent gametophyte, the stemlike seta brings it to the sporangium (or capsule), which makes up to 50 million spores. A calyptra protects the capsule before it releases the spores, and the upper part of the capsule, the peristome, allows the spores to be distributed gradually.

Front 27

Why are mosses able to live in colder and drier environments than vascular plants?

Back 27

They can suffer more dessication and survive.

Front 28

What does the moss Sphagnum do?

Back 28

Peat moss inhabits wetlands, makes up peat, makes phenolic compounds that resist decay and acids which hamper bacteria.

Front 29

How do humans use Sphagnum?

Back 29

during wartime to cover wounds, as a soil conditioner, to pack plant roots (absorbing water), and to burn as peat

Front 30

What evolved between mosslike ancestors and vascular plants?

Back 30

protracheophyte polysporangiophytes, which had branched, independent sporophytes similar in size to the gametophytes

Front 31

What was the first known vascular plant?

Back 31

Cooksonia, an extinct plant from 408Ma with lignified cells similar to pteridophyte xylem

Front 32

How many phyla of plants are there, and how are they distributed?

Back 32

10, 3 bryophyte, 2 pteridophyte, 4 gymnosperm, and 1 angiosperm

Front 33

What are the two phyla of seedless vascular plants and examples of their members?

Back 33

Lycophyta (lycophytes) and Pterophyta (ferns, whisk ferns, horsetails)

Front 34

Which pteridophyte phyla diverged first?

Back 34

Lycophyta

Front 35

What is the main difference between lycophyte leaves and other vascular plant leaves?

Back 35

Lycophyte leaves are simpler and smaller, called microphylls, while other leaves are bigger due to branching of the vascular system, and are called megaphylls.

Front 36

Hypothetically speaking, how did megaphylls evolve?

Back 36

Some kind of webbing joined nearby microphylls, making branched leaves

Front 37

Summarize the life cycle of a fern.

Back 37

A spore develops into a gametophyte, which makes sperm and eggs at different times to cross-fertilize, and fertilization results in a new sporophyte, which develops as a fern with sporangia that release new spores.

Front 38

Why did big lycophytes die off?

Back 38

These lycophytes were giant, more than 40 meters tall, but required the warm and moist environment of the Carboniferous period, and died out when the weather cooled and dried after it.

Front 39

About how many species of lycophytes are there?

Back 39

a thousand

Front 40

Describe the structure of a lycophyte sporophyte.

Back 40

Vertical stems hold small green microphylls (leaves), while horizontal stems attach to the roots. Sporophylls are specialized cone-shaped leaves with sporangia.

Front 41

How do lycophytes reproduce?

Back 41

The sporophyte releases oil-rich spores in clouds that disperse to make tiny haploid gametophytes that are either above ground photosynthesizers or underground fungi symbionts.

Front 42

What are the three types of pteridophytes in phylum Pterophyta?

Back 42

psilophytes (whisk ferns), sphenophytes (horsetails) and ferns

Front 43

What's special about psilophytes?

Back 43

They are very similar to Cooksonia, have Y-shaped (dichotomous) branching, and don't have true leaves and roots, but that actually devolved from a fernlike ancestor

Front 44

How many species of sphenophytes are there?

Back 44

15, all in the genus Equisetum

Front 45

Describe the structure of horsetails.

Back 45

upright photosynthetic stems and horizontal rooted stems (rhizomes) with air channels going through the plant to get oxygen throughout and sporangia-bearing cones

Front 46

How many species of ferns are there?

Back 46

>12k

Front 47

Describe the structure of ferns.

Back 47

horizontal rhizomes grow big compound leaves known as fronds with lots of vascular branching

Front 48

How do ferns release their spores?

Back 48

Sori, which are clusters of sporangia on the undersides of their leaves, launch their spores into the wind.

Front 49

When was the Carboniferous period?

Back 49

360-290 Ma

Front 50

How did coal form?

Back 50

Peat, dead organic matter primarily made in the Carboniferous of seedless vascular plants, piled up, was buried by ocean sediments, and compressed into coal by heat and pressure.

Front 51

What is the difference between a homosporous plant and a heterosporous plant?

Back 51

A homosporous plant only makes one type of spore, so the gametophyte is bisexual, while a heterosporous plant makes megaspores, which become female gametophytes, and microspores, which become male gametophytes.