CH29

Question 1

Describe

The derived characteristics common to all land plants

Answer 1

• Eukaryotic
• Cellulose cell walls
• Develops from embryos
• Possesses chloroplasts, mitochondria
• Alternates generations

Question 2

Define

Embryo

Answer 2

Diploid multicellular structure enclosed in maternal tissue

Algae (charophytes) don’t develop from embryos

Question 3

Define

Sporopollenin

Answer 3

Layer of durable polymer in charophytes, prevents spores from drying out

Question 4

What are the derived traits of plants?

Answer 4

• Alternation of generations
• Multicellular, dependent embryos
• Walled spores
• Multicellular gametangia
• Apical meristems

Question 5

Describe the alternation of generations in plants

Answer 5

• The diploid sporophyte (mature plant) produces by meiosis haploid spores
• The spores do mitosis and become a haploid gametophyte
• The gametophyte does mitosis and produces gametes
• Fertilization occurs, a diploid zygote is produced and matures into a sporophyte

Question 6

What are the dominant stages in ferns and moss?

Answer 6

Moss is haploid dominant, while ferns are diploid dominant

Question 7

Describe

Walled spores

Answer 7

Spores covered by sporopollenin, produced in sporangium from meiosis of sporophytes

Question 8

Describe

Multicellular gametangia

Answer 8

Organ in which gametes are produced, archegonia for eggs and antheridia for sperm

Question 9

Describe

Apical meristems

Answer 9

Localized regions of cell division

Question 10

Describe

Vascular plants

Answer 10

• Grade, united by their having a complex vascular tissue system
• Depend on water availability (swimming sperm)
• Formed of 2 clades, lycophytes (club mosses, etc…) and monilophytes (ferns, more diversified than lycophytes), both seedless vascular

Question 11

Describe

Bryophytes

Answer 11

• First clade, composes of non-vascular plants
• Depend on water availability (swimming sperm)
• 3 phyla: liverworts, mosses, hornworts
• Very present in peatlands, ecosystems very important for environment, hold 20-30% of organic carbon despite being 3% of Earth surface

Question 12

Describe

The third clade, following bryophytes and vascular plants

Answer 12

Vascular plants with seeds, composed of two clades:
* Gymnosperms: seeds not enclosed in chambers (conifers); heterosporous
* Angiosperms: seeds in chambers (90% of plants)

Question 13

In what order did the 3 clades appear?

Answer 13

• Land plants (470 mya)
• Vascular plants (425 mya)
• Extant seed plants (305 mya)

Angiosperms (140 mya)

Question 14

What are the two types of vascular tissue?

Answer 14

• Xylem: water and mineral conduction, contain tracheid, tube-shaped cell for upwards carry
• Phloem: distribution of sugars

Question 15

Describe

Roots

Answer 15

Organs that absorb water and nutrients from the soil. They also anchor vascular plants

Question 16

Describe

Leaves

Answer 16

Primary photosynthetic organ of vascular plants
* microphylls: small, spine-shaped leaves
* megaphylls: large, vascular leaves