Bryophytes

Question 1

What are the three phyla?

Answer 1

Liverworts, Hornworts and mosses

Question 2

What derived traits are shared with tracheophytes?

Answer 2

Multicellular embryos, apical meristems

Question 3

What features are lacking in bryophytes that are present in tracheophytes?

Answer 3

Roots, leaves and lignified transport system

Question 4

What is the dominant stage?

Answer 4

Gametophyte

Question 5

What is a protonema?

Answer 5

Characteristic of germinating moss spores, grow into a mass of filamentous cell with a large surface area

Question 6

What is the gamete producing structure know as?

Answer 6

Gametophore - bears the gametangia

Question 7

Why do gametophytes generally form ground hugging carpets?

Answer 7

Cant support a tall structure

Question 8

Why is the structure very thin?

Answer 8

So they can distribute nutrients without a vascular system

Question 9

What are rhizoids?

Answer 9

Long tubular single cells, not composed of toissues, role id to anchor the plants

Question 10

Why are most bryophytes found in moist habitats?

Answer 10

Because they require a thin film of water for reproduction to take place

Question 11

How are sporophytes of bryophytes different than in tracheophytes?

Answer 11

Cannot live independently, require the gametophyte for survival, smallest sporophyte of all extant plant groups

Question 12

What are the features of the sporophyte?

Answer 12

A foot, seta and sporangium (capsule)

Question 13

What is the role of the foot?

Answer 13

Embedded in the archegonia, obtains nutrients from the gametophyte

Question 14

What is the role of the seta?

Answer 14

Conducts the materials from the foot to seta, elongated in some to elevate sporangium for better dispersal

Question 15

What is the role of the sporangia?

Answer 15

uses nutrients to produce spores by meiosis

Question 16

What is the peristome?

Answer 16

Ring of teeth like structures on capsule, that open under dry conditions and close in wet, to allow spores to be dispelled gradually

Question 17

What feature do hornworts and mosses have that is lacking in liverworts?

Answer 17

Specialised stomata for exchange of co2 and oxygen and to minimise water loss

Question 18

What are homospores?

Answer 18

Spores of one kind, not differentiated by sex

Question 19

What is zooidogamous?

Answer 19

type of plant reproduction in which male gametes (antherozoids) swim in a film of water to the female gametes (archegonium)

Question 20

What is exoscopic embryogeny?

Answer 20

apex of embryo pointed towards the neck of archegonium

Question 21

How are the spores dispersed?

Answer 21

By wind

Question 22

What are epiphytes?

Answer 22

Can grow on another plant

Question 23

How are bryophytes protected from UV radiation?

Answer 23

Phenoilc compounds

Question 24

Where do bryophytes colonise?

Answer 24

Bare rocks and soil surfaces for trees

Question 25

What happened in the mid ordovician?

Answer 25

First land plants evolve, bryophytes widespread

Question 26

What happened in the early silurian?

Answer 26

Tracheophytes evolve and overtake bryophytes in dominant vegetation

Question 27

What happened in the mid Devonian?

Answer 27

trees and forests evolved, give rise to new habitats for bryophytes to exist

Question 28

How are bryophytes important in the ecosystem?

Answer 28

Reduce the loss of nitrogen, can retain concentration in the soil