CH 25

Question 1

what TYPE of PLANTS represents a small fraction of plants in our environment

however, used to dominate in the past?

+ in what era did they specifically dominate?

Answer 1

seedless plants

Carboniferous period

Question 2

product of the decomposition of seedless plants?

Answer 2

coal

Question 3

all plants, including _____ and ____, are (mono/para/polyphyletic) ?

Answer 3

green algae and land plants

monophyletic

Question 4

what EVOLUTIONARY TRANSITION did past plants undergo to become the plants we know today?

+ what did they aim to avoid through their development (4)?

+ did all plants fully evolve?

Answer 4

TRANSITION from water to land

• developed strategies to:
  1. avoid drying out
  2. disperse reproductive cells
  3. structural support
  4. capturing and filtering sunlight

NOT all plants gained complete independence for water… MOST seedless plants still require moist environment for reproduction

whereas SEED PLANTS already developed adaptations that allow them to populate even without water

Question 5

land plants arose within the _______ that includes the _______ (3)

Answer 5

• archaeplastida

1. rhodophyta
2. chlorophyta
3. charaphyta

Question 6

are algae considered to be plants?

why or why not?

Answer 6

most do but some dont since only green algae (Chlorophytes and Charophytes) share common characteristics with land plants (chlorophyll a and b and carotene)

Question 7

are all algae photosynthetic?

if yes, what makes them different from plants?

if no, what is unique about them?

Answer 7

YES - they all contain chloroplast but only green algae has:

1. the same chloroplast type as plants
2. became photosynthetic via the same path as plants

Question 8

ARCHAEPLASTIDA

• organisms or groups (6) under this?
• how did they GENERALLY arrive to becoming photosynthetic?

Answer 8

1. red algae
2. green algae
3. mosses
4. ferns
5. gymnosperms
6. angiosperms

• became photosynthetic by forming a PRIMARY endosymbiotic relationship with a green, photosynthetic bacterium

Question 9

HOW did organisms outside of the archaeplastida become photosynthetic?

+ organism examples (2)

Answer 9

STRAMENOPILES
1. brown algae
2. golden algae

• through SECONDARY / TERTIARY endosymbiotic

(events engulfing cells that already contained an endosymbiotic cyanobacterium)

Question 10

____ is the process of drying out in plants

Answer 10

DESICCATION

Question 11

IMPORTANCE of WATER in plants (5)

Answer 11

1. cellular processes
2. prevents desiccation
3. buoyancy for structural support
4. filters UV rays
5. reproduction (male gametes swimming to female gametes)

Question 12

IMPORTANCE of EVOLUTIONARY TRANSITION from water to land in plants (4)

Answer 12

1. sunlight is abundant in land
2. readily available CO2
3. no predators
   - land plants evolved before animal plants so they were safe until land was colonized by animals
4. modifications in plants as response to danger (e.g. spines, thorns, pitcher leaves)

Question 13

SURVIVAL STRATEGIES of plants as response to lack of water after evolutionary transition (3)

Answer 13

1. tolerance
   - mosses wait until water becomes available
2. colonization of environments with high humidity
   - ferns live in damp and cool places
3. resistance to desiccation
   - cactuses evolved spikes that minimize loss of water despite living in dry places

Question 14

MOST SUCCESSFUL adaptation of plants (4)

+ however, these are not present in ______ and ______

Answer 14

1. alternation of generations (life cycle)
2. apical meristem tissues in roots and shoots
   - for growth towards the sun
3. waxy cuticle to resist desiccation
4. cell walls w/ LIGNIN to support structures off the ground

*lacks in algae and mosses

Question 15

other term for LAND PLANTS

+ why

Answer 15

EMBRYOPHTES

• female gametophyte provides protection and nutrients to embryo

Question 16

Which of the following statements about plant divisions is false?

a. Lycophytes and pterophytes are seedless vascular plants.
b. All vascular plants produce seeds.
c. All non-vascular embryophytes are bryophytes.
d. Seed plants include angiosperms and gymnosperms.

Answer 16

b. All vascular plants produce seeds. (False — ferns and lycophytes are vascular but seedless)

a. true
c. bryophytes ( mosses, liverworts, and hornworts) are NONVASCULAR but algae (which are not under bryophytes) are ALSO NONVASCULAR
d. these are the two major groups of seed-producing plants

Question 17

Which of the following statements about the moss life cycle is false?

a. The mature gametophyte is haploid.
b. The sporophyte produces haploid spores.
c. The calyptra buds to form a mature gametophyte.
d. The zygote is housed in the venter.

Answer 17

c. The calyptra buds to form a mature gametophyte. (False — gametophytes come from spores, not calyptra.)

a. moss gametophytes (and gametophytes in general) are haploid
b. true
d. true

Question 18

Which of the following statements about the fern life cycle is false?

a. Sporangia produce haploid spores.
b. The sporophyte grows from a gametophyte.
c. The sporophyte is diploid and the gametophyte is haploid.
d. Sporangia form on the underside of the gametophyte.

Answer 18

d. Sporangia form on the underside of the gametophyte. (False — they form on the sporophyte.)

a. true
b. true - refer to lifecycle in lab flashcards again
c. true

Question 19

The land plants are probably descendants of which of these groups?

a. Green algae
b. Red algae
c. Brown algae
d. Angiosperms

Answer 19

a. Green algae

b. red algae are not really considered to have the same characteristics as plants
c. brown algae are not under ARCHAEPLASTIDA, which houses plants and red & green algae
d. angiosperms are a group even lower than land plants

Question 20

Alternation of generations means that plants produce:

a. only haploid multicellular organisms
b. only diploid multicellular organisms
c. only diploid multicellular organisms with single-celled haploid gametes
d. both haploid and diploid multicellular organisms

Answer 20

d. Both haploid and diploid multicellular organisms

self explanatory

Question 21

Which of the following traits of land plants allows them to grow in height?

a. alternation of generations
b. waxy cuticle
c. tracheids
d. sporopollenin

Answer 21

c. Tracheids (part of the vascular tissues - xylem)

a. life cycle-no direct influence on plant height
b. prevents desiccation, not encourage plant height
d. protects reproductive spores

Question 22

How does a haplontic plant population maintain genetic diversity?

a. Zygotes are produced by random fusion.
b. Gametes are created through meiosis.
c. Diploid spores undergo independent assortment during mitosis.
d. The zygote undergoes meiosis to generate a haploid sporophyte.

Answer 22

a. Zygotes are produced by random fusion.
- Random gamete fusion introduces genetic variation in haplontic organisms.

b. gametes are produced by MITOSIS
c. there are no DIPLOID SPORES or diploid anything in a haplontic plant
d. the zygote does undergo meiosis, but it produces haploid spores, not a sporophyte (diploid)

Question 23

What characteristic of Charales would enable them to survive a dry spell?

a. sperm with flagella
b. phragmoplasts
c. sporopollenin
d. chlorophyll a

Answer 23

c. sporopollenin - tough coating protects zygotes/spores from desiccation

a. no connection
b. no connection — helps in cell division
d. not specific to drought resistance

Question 24

LIFE CYCLE OF THE FF:

1. Charophyta
2. Chlorophyta
3. Rhodophyta
4. Angiosperms
5. Mosses

Answer 24

1. haplontic
2. diplontic
3. diplohaplontic
4. diplohaplontic
5. diplohaplontic

Question 25

Which one of these characteristics is present in land plants and not in Charales? a. alternation of generations b. flagellated sperm c. phragmoplasts d. plasmodesmata

Answer 25

a. alternation of generations - charophyta exhibit haplontic life cycle

Question 26

A scientist sequences the genome of Chara, red algae, and a tomato plant. What result would support the conclusion that Charophytes should be included in the Plantae kingdom? a. The Chara genome is more similar to the red algae than the tomato plant. b. All three genomes are distinctly different. c. The Chara genome is more similar to the tomato plant genome than the red algae genome. d. The tomato plant genome is distinct from the red algae genome.

Answer 26

c. The Chara genome is more similar to the tomato plant genome than the red algae genome. a. red algae are less related to plants b. doesnt support any group d. not related to chara

Question 27

Which of the following features does not support the inclusion of Charophytes in the Plantae kingdom? a. Charophyte chloroplasts contain chlorophyll a and b. b. Charophyte plant cell walls contain plasmodesmata to allow transfer between cells within multicellular organisms. c. Charophytes do not exhibit growth throughout the entire plant body. d. Charophytes are multicellular organisms that lack vascular tissue.

Answer 27

c. Charophytes do not exhibit growth throughout the entire plant body. - plants grow through apical meristems a. plants have chlorophyll a and b b. plants contain plasmodesmata d. some plants dont have vascular tissues

Question 28

Which of the following structures is not found in bryophytes? a. a cellulose cell wall b. chloroplast c. sporangium d. root

Answer 28

d. root — Bryophytes do not have true roots, only root-like rhizoids.

Question 29

Stomata appear in which group of plants? a. Charales b. liverworts c. hornworts d. mosses

Answer 29

c. hornworts a. algae dont have stomata b. no stomata d. some mosses DO HAVE stomata but not all

Question 30

The chromosome complement in a moss protonema is: a. 1n b. 2n c. 3n d. varies with the size of the protonema

Answer 30

a. mosses are haplontic plants

Question 31

A botanist travels to an area that has experienced a long, severe drought. While examining the bryophytes in the area, he notices that many are in the same life-cycle stage. Which life-cycle stage should be the most common? a. zygote b. gametophyte c. sporophyte d. archegonium

Answer 31

b. gametophyte — This is the dominant stage in bryophytes and can survive periods of dormancy. a. Zygotes are short-lived and found inside the archegonium. c. Sporophytes are dependent on gametophytes and not dominant. d. This is part of the gametophyte but not a full stage.

Question 32

Microphylls are characteristic of which types of plants? a. mosses b. liverworts c. club mosses d. ferns

Answer 32

c. Club mosses (lycophytes) are defined by microphylls — small leaves with a single vein. a. Mosses do not have true leaves. b. Liverworts may have leaf-like structures, but not microphylls. d. Ferns have megaphylls

Question 33

The dominant organism in fern is the ________. a. sperm b. spore c. gamete d. sporophyte

Answer 33

d. sporophyte a. microscopic, not organism b. reproductive cells, not organism c. reproductive cells, not organism

Question 34

What seedless plant is a renewable source of energy?

Answer 34

Sphagnum moss — Also called peat moss, Sphagnum is harvested for peat, a renewable energy source.

Question 35

How do mosses contribute to returning nitrogen to the soil? a. Mosses fix nitrogen from the air. b. Mosses harbor cyanobacteria that fix nitrogen. c. Mosses die and return nitrogen to the soil. d. Mosses decompose rocks and release nitrogen.

Answer 35

b. Mosses harbor cyanobacteria that fix nitrogen. a. Mosses themselves do not fix nitrogen. c. This happens over time but is not the main way they help fix nitrogen. d. Decomposition of rock affects minerals, not nitrogen.

Question 36

Why did land plants lose some of the accessory pigments present in brown and red algae?

Answer 36

Land plants evolved from green algae, which already had fewer accessory pigments compared to red and brown algae. On land, light is more abundant and less filtered, so many accessory pigments used for capturing limited underwater light were no longer necessary.

Question 37

Describe a minimum of two ways that plants changed the land environment to support the emergence of land animals.

Answer 37

1. produced Oxygen via photosynthesis 2. stabilized soil with roots 3. food 4. shelter

Question 38

To an alga, what is the main advantage of producing drought-resistant structures?

Answer 38

for survival and reproduction in dry conditions