Exam 2: Lecture 11 (chapter 29)

Question 1

What are plants

Answer 1

Autotrophic organisms that lack motility, and have cellulose-based walls; use growth and movement to acquire resources

Question 2

Define the alternation of generations

Answer 2

when an organism alternates between two distinct forms: a multicellular diploid phase (sporophyte) and a multicellular haploid phase (gametophyte)

Question 3

What traits do plants share with protists

Answer 3

1. Multicellular (red, brown, green algae)
2. Cell walls made of cellulose (G. Algae, Dinoflagellates, Brown algae)
3. Chloroplasts with chlorophyll A and B (G Algae, euglenids, dinoflagellates)

Question 4

What is the most common ancestor of plants from protists and what traits do they share

Answer 4

Charophytes,
- Peroxisome enzymes
- Flagellated sperm
- Formation of phragmoplast
- Rose-shaped complexes (cellulose synthesis)
- DNA similarities (chloroplasts, mitochondrial DNA)

Question 5

What are pros of plants moving to land

Answer 5

1. More access to sunlight
2. More CO2
3. Nutrient-rich soil

Question 6

What are some cons of moving to land

Answer 6

1. Lack of water (harder to access)
2. Greater effect of gravity (harder to grow upwards)
3. More risk to gametes/offspring
4. Less space to grow (other plants?)

Question 7

What are four main characteristics that separate plants from charophytes

Answer 7

1. Alternation of generations
2. Walled spores produced In sporangia
3. Multicellular gametangia
4. Apical Meristems (allows for indefinite growth)

Question 8

Plants are called _______ because their ______ is dependent on the parent plant

Answer 8

Embryophytes, embryo

Question 9

The _______ produces ______ in organs called sporangia. Diploid cells called _______ then undergo meiosis to generate haploid cells.

Answer 9

Sporophyte (2N), spores, sporocytes

Question 10

What structure protects spores from harsh, dry environments

Answer 10

Sporopellenin, which makes spores resistant to harsh environments

Question 11

Female _______ produces egg cells, and male ______ produce sperm cells.

Answer 11

Archegonium, antheridia

Question 12

Why is the Apical Meristem an important characteristic of plants

Answer 12

Plants grow from the apical meristem, allowing them to differentiate into various tissue such as leaves, flowers, fruits, and roots.
- The Apical Meristems allows plants to exhibit indeterminate growth (growth as long as alive)

Question 13

What are derived traits of land plants?

Answer 13

Cuticle: A waxy covering on their leaves, preventing water loss and protecting against microbes

Symbiotic relationship with Mycorrhizal fungi, allowing nutrient absorption.

Question 14

What are the three main categories of plants

Answer 14

• Nonvascular plants (mosses, liverworts, hornworts)
• Seedless vascular plants (Ferns, Club mosses, whisk ferns, horsetails)
• Seed plants (pines, flowering plants, confiers, etc…)

Question 15

What defines non-vascular plants

Answer 15

They do not have any vascular tissue, preventing them from growing large, staying close to the ground.
- Lack of Phloem and Xylem means they rely on diffusion through their leaves for water/nutrients.

Question 16

What are Bryophytes and what are their three phyla

Answer 16

Bryophytes include all nonvascular plants, which are small and widespread
- Bryophyta (mosses)
- Hepatophyta (liverworts)
- Anthocerophyta (hornworts)

Question 17

Define some characteristics of Mosses

Answer 17

• Thrive in moist habitats (nutrient/water absorption through leaves)
• Rhizoids anchor the plant
• Sperm is produced in antheridia and eggs are produced in archegonia

Question 18

All ________ phyla spend most of their lives as ________, and their _______ remain attached to gametophytes

Answer 18

Bryophyte, Gametophytes, sporophytes

Question 19

Name and describe bryophyte sporophyte organs

Answer 19

Foot: Absorbs nutrients from gametophyte
Seta: conducts nutrients to capsule
Capsule: produces spores
Peristome: tooth-like structures surrounding the opening of the capsule

Question 20

Describe the diversity of Hepatophyta (liverworts)

Answer 20

• Leaves are similar to mosses, but have two rounded lobes
• Thallus: Body without roots, stems, or leaves
• Air pores (not stomata)
• Asexual reproduction with gemmae in gemmae cups

Question 21

Describe the diversity of Anthocerophyta’s (Hornworts)

Answer 21

• Grow in moist soil (100-150 species)
• Have no Seta, sporangium releases spores by splitting open at the tip
• DO HAVE stomata (allows easier gas transfer)

Question 22

What separates seedless vascular plants from non-vascular plants

Answer 22

Seedless vascular plants evolved vascular tissue that allows them to transport nutrients and water around more easily

Question 23

What makes up plant vascular tissue

Answer 23

Xylem: conducts water and nutrients (cohesion)
Phloem: distributes organic products throughout the plant

Question 24

What is the advantage of having vascular tissue for land plants?

Answer 24

Vascular tissue allows land plants to grow taller, since they can provide structure support (filled with water, stiffer body).

Question 25

_______ anchor plants and absorb nutrients/water, and ______ increase surface area to capture light

Answer 25

Roots, Leaves

Question 26

_________ are small leaves with one vein, and _______ are leaves with a branched vascular system, allowing higher photosynthetic productivity.

Answer 26

Microphylls, Megaphylls

Question 27

What are sporophylls?

Answer 27

Modified leaves that bear sporangia

Question 28

What is the sporangia

Answer 28

A receptacle where spores of formed, most seedless vascular plants are homosporous

Question 29

What are the steps of homosporous spore production

Answer 29

Sporangium on Sporophyll —> Single type of spore —> Bisexual Gametophyte (both sperm and egg)

Question 30

What are the steps of heterosporous spore production

Answer 30

1. Megasporangium on megasporophyll —> Megaspore —> Female Gametophyte –> Eggs
2. Microsporangium —> Microspore —> Male Gametophyte —> Sperm

Question 31

Lycophyte sporophytes have _______

Answer 31

Microphylls

Question 32

Describe the structure of Fern leaves

Answer 32

Fern leaves are megaphylls called fronds
- Fronds are divided into smaller segments and require external water for production