Lecture 8: plants and fungi

Question 1

Charophytes

Answer 1

• sister group to land plants
• type of green algae
• gives us clues as to how land plants evolved

Question 2

Plant synapomorphies

Answer 2

• alternation of generations
• produce haploid spores in sporangia
• have multicellular gametangia (structure that encloses gametes)
• have apical meristem– localized region where cell division occurs

Question 3

When did plants colonize land?

Answer 3

500 MYA

Question 4

When did the first forests appear?

Answer 4

370 MYA

Question 5

When was the origin of vascular plants?

Answer 5

425 MYA

Question 6

When was the origin of seed plants?

Answer 6

360 MYA

Question 7

Bryophytes

Answer 7

• Non vascular plants
• different than all other land plants because the gametophyte is the dominant generation
• non woody, herbacious plants
• often found in moist environments, need water to reproduce
• form low mats, lack of vascular tissue limits size
• EX: liverworts, mosses and hormworts

Question 8

Seedless vascular plants

Answer 8

• gametophyte is the reduced stage
• sporophyte tends to be the dominant stage
• found in moist environments, less tied to water, don’t need water for fertilization

Question 9

Gymnosperms

Answer 9

• seed plants
• plants that have cones
• sporophyte is dominant stage
• naked seeds—> not enclosed in ovary, exposed on modified leaves that form cones
• EX: pine trees, Douglas fir, Juniper, Grinkos

Question 10

Angiosperms

Answer 10

• seed plants
• sporophyte is the dominant stage
• flowering plants
• largest group today

Question 11

Cells that make up vascular tissue

Answer 11

• Xylem and phloem
• Xylem= water and minerals
• phloem= sugar, amino acids, etc

Question 12

Seed

Answer 12

• embryo + food supply in a protective coat
• can withstand harsh conditons
• Advantages: detachable, have their own food source
• produced from the female gametophyte stage

Question 13

Pollen

Answer 13

• male gametophyte within sporophyte
• Advantages: can be carried long distances by water, wind or animals
• no reliance on water for fertilization
• haploid male stage but contained with some sporophyte diploid tissue

Question 14

Characteristics of fungi

Answer 14

• widely dispersing spores
• heterotrophs– not photosynthetic, get their food by absorbing it from environment
• many parasites (some pathogenic) and mutalists
• unicellular (yeasts and filamentous forms) and multicellular
• sexual and asexual
• fungal walls contain chitin, a nitrogen rich polysaccharide
• multicellular fungi are composed of hyphae= tubular cells that maximize volume to surface area ratio

Question 15

Opisthokonts

Answer 15

• larger phylogenetic group that includes animal and fungi
• monophyletic group
• evolved from a unicellular flagellated ancestor
• multicellularity appears to have independently evolved in lineages leading to animals and fungi