Bryophytes

Question 1

Characteristics plants share with green algae

Answer 1

• primary photosynthetic pigments (chlorophyll a, b , carotenoids)
• primary energy storage compound (starch)
• cell walls cellulose
• form phragmoplasts and cell plates during division

Question 2

phragmoplasts

Answer 2

complex of microtubules and endoplasmic reticulum.
- acts as a framework for cell plate assembly and subsequent formation of the future cell wall separating the two daughter cells.

Question 3

pectin

Answer 3

pectin helps keep the walls of adjacent cells joined together.

Question 4

How do plants differ from algae

Answer 4

moss have:
- epidermal cells have a waxy cuticle
- multicelled sporangia surround developing spores
- multicelled gametangia surround developing gametes
- embryos are surrounded by protective cells

Question 5

Specific bryophye characteristics:

Answer 5

• no vascular tissue… nonvascular plants lack lignified water-conducting tissues
• gametophyte generation is dominant
• fewer specialized tissue
• motile, multiflagellated sperm

Question 6

three classes of bryophyta

Answer 6

• class sphagnopsida
• class bryopsida
• class andreaopsida

Question 7

class sphagnopsida

Answer 7

peat mosses

Question 8

class bryopsida

Answer 8

true mosses

Question 9

class andreaopsida

Answer 9

rock mosses

Question 10

phylum bryophyta structure of leaves

Answer 10

• gametophyte thallus is threadlike with narrow leaflike projections attached to stem
• no veins
• thin
• no petiole (leafstalk)
• no mesophyll or stomata

Question 11

phylum bryophyta axis structure

Answer 11

• no conductive tissue (not a stem)
• may have hydroids (sponge cells that soak up water)

Question 12

phylum bryophyta rhizoids

Answer 12

• threadlike, anchor base
• help absorb but not a root

Question 13

Phylum bryophyta gametangia

Answer 13

• form by mitosis near tips of gametophyte or on special stalks

Question 14

gametangia

Answer 14

specialized organ or cell in which gametes are formed

Question 15

antheridia

Answer 15

male, looks like hot dog on stick, produces sperm

Question 16

archegonia

Answer 16

female, produces ovum

Question 17

paraphyses

Answer 17

grows around the anteridium/archegonium

Question 18

moss fertilization

Answer 18

• antheridium swells and forces sperm out
• archegonia secrete attractive molecules
• sperm swims down neck of archegonium and unites with egg

Question 19

moss sporophyte develop from zygote (2n process)

Answer 19

• venter of archegonium expands as the zygote is breaking out
• sporophyte is formed from the expanding archegonium
• calyptra and operculum break away from the peristome
• sporocytes are undergoing meiosis in the sporangium to produce spores
• spores are now freed through the peristome from the capsule

Question 20

asexual reproduction moss (1n process)

Answer 20

• spores grow into protonema
• produces buds which grow into either female or male gametophytes
• undergo fertilization process, restart cycle

Question 21

Liverworts

Answer 21

phylum hepatophyta

Question 22

two groups of liverworts

Answer 22

• thalloid liverworts (marchantia)
• leafy liverworts (frullania, tropical 80% of species)

Question 23

external structure of thalloid liverwort

Answer 23

external: dichotomously forked, robust and 30 cells thick
- upper surface: polygons, pores that stay open
- lower surface: rhizoids

Question 24

internal strucutre thalloid liverwort

Answer 24

• hollow chambers
• upper: green, pore
• walls: food storage
• columns of chlorenchyma (photosynthesizing cells)

Question 25

liverwort gametophores

Answer 25

antheridiophore (producing sperm at tip) archegoniophore (each produce 1 egg, palm tree)

Question 26

liverwort fertilization (2n)

Answer 26

- young sporophyte formed from fertilized egg - sporophyte structure: foot, seta, calyptra, sporocytes capsule - capsule splits at maturity to release spores

Question 27

liverwort asexual reproduction (1n)

Answer 27

- spores form female and male gametophores - most liverworts can reproduce asexually by means of gemmae, which are disks of tissues produced by the gametophytic generation. The gemmae are held in special organs known as gemma cups and are dispersed by rainfall. - can also reproduce with fragmentation

Question 28

Hornworts

Answer 28

- phylum anthocerotophyta - mostly on moist ground, some on trees

Question 29

structure of hornworts

Answer 29

- thallus internal: mucilage filled chamber network (mucus) N-fixing bacteria (cyanobacteria) 1 chloroplast/cell with large pyrenoid ( store starch)

Question 30

hornwort sexual reproduction

Answer 30

- gametangia buried in surface of thallus - fertilization occurs in water

Question 31

hornwort sporophyte structure

Answer 31

- foot attaches - no seta - has meristem (rapidly dividing cells) - grows upward like a horn -sporocytes form from spores by meiosis - spores released by splitting of sporophyte

Question 32

hornwort asexual reproduction

Answer 32

- fragmentation or tubers