Nonvascular Plants

Question 1

Three Lineages of nonvasular plants

Answer 1

1. Hepatophytes (liverworts) - most ancient
2. Bryophytes (mosses)
3. Anthocerophytes (hornworts)
   
   • vasuclar sister

Question 2

Typical Features (in land plant respects)

Answer 2

1. Heteromorphic alternation of generations
2. Gametangia enclosed by a sterile layer
   of cells
3. Retention of zygote (no mech of dispersal)
4. Multicellular sporophytes
5. Sporopollenin in spore walls
6. Parenchyma
7. Plasmodesmata
8. Cutical
9. Stomata

Question 3

Cutical

Answer 3

Wax lipid layer on outside of the plant cells

Question 4

Two traits that distinguish nonvascular plants from other land plants

Answer 4

1. No lignified vascular tissue
   
   • limits plant height
2. Haploid phase dominant
   
   • gametophyte is the larger
   • Multicellular sporophyte remains
     attached and is nutritionally dependent
     on gametophyte

Question 5

Water uptake and movement in nonvascular plants

Answer 5

1. Absorption of water and dissolved
   minerals is directly from the environment
2. Water movement
    - external water movement via capillary 
      action
    - Cell-to-cell osmosis through cell 
      membranes
    - Diffusion through cell wall
    - Water-conduction cells in some 
      mosses and liverworts

Question 6

Alternation of heteromorphic generations in nonvascular plants

Answer 6

1. Homosporous
2. Sporophyte
3. Gametophyte

Question 7

Homosporous

Answer 7

Only one type of spore

Question 8

Sporophyte

Answer 8

Sporangia: spore-producing structure

Question 9

Gametophyte

Answer 9

Gametangia: gamete-producing multicellular structure with a surrounding layer of sterile cells

• Antheridia
• Archegonia (instead of oogonia)

Question 10

Heptophytes: Habitats

Answer 10

1. found in moist, shaded habitats
2. highest diversity in tropical rain forests
3. A few aquatic species
4. Epiphytes

Question 11

Liverworts are….

Answer 11

the closest living relatives of the earliest land plants

Question 12

Bryophytes: Habitats

Answer 12

1. Perenials
2. Most in moist, shaded habitats
3. important pioneering species
4. Epiphytes

Question 13

Bryophytes: Gametophytes

Answer 13

1. Dominate life cycle
2. main axis with blades
   
   • ‘leaves’ in a spiral arrangement
   • Gametangia at shoot tips
3. Numerous discoidal plastids (flat, circular)
4. Rhizoids

Question 14

Bryophyte: ‘Leaves’

Answer 14

1. one cell thick
2. mid-rib in many
3. No stomata
4. Cutical
   * example of convergent evolution