Phylum bryophyta

Question 1

Moss habitat

Answer 1

Grow packed closely together in mats or cushions on rocks, soil or as epiphytes on the trunks and leaves of forest trees

Largest diversity of bryophytes

Question 2

How are bryophyta distinguished from tracheophytes

Answer 2

-dominant phases of life cycle is haploid, gametophyte
-sporophytes are very short lived and nutritionally dependent on their gametophytes
-bryophytes lack vascular tissue

Question 3

What does gametophyte mean

Answer 3

All organs and tissues that are apart of the haploid generation

Question 4

What are the two developmental stages of the gametophyte of mosses

Answer 4

Protonema - first part of the moss that develops from the germinating spore=filamentous form similar to green algae

Gametophores

Question 5

Moss leaves

Answer 5

-composed of a single layer of cells
-may have Costa
-parallel lamellae with thin-walled photosynthetic cells, separated by narrow fissures-> capillary spaces for water storage
-photosynthesis cells protected from desiccation by unrolling of sclerotic margins

Question 6

In mosses, ________ compose much of the stem and thick walled cells called _____ form structural support

Answer 6

Cortical cells (parenchyma cell)

Stereids

Question 7

Rhizoids of mosses

Answer 7

Multicellular but uniseriate, forming a filament

Question 8

Bryophyte conduction

Answer 8

Hydroids conduct water and leptoids conduct sugars

Arranged as in a vascular plants (tracheophytes): water conducting cells stranded by the sugar-conducting cells

Unlike most tracheophytes, mosses retain conducting cells in both generations, but the haploid generation is the first to lose leptoids evolutionarily

Question 9

Bryophyte water conduction types

Answer 9

Ectohydric-lack specialized cells for internal conduction-> water is conducted externally through capillary action

Mixohydric-some water conducted externally + hydroids transport water and nutrients

Endohydric-an internal conducting system exists that is analogous to the conducting system of vascular plants

Question 10

Bulbils

Answer 10

Give rise to immature gametophytes following the formation of protonema

Question 11

Asexually moss reproduction

Answer 11

Reproduce vegetatively via Gemma, bulbils budding from the gametophyte surfaces or fragmentation of the branching protonema

Question 12

Bryophyte sperm transfer requires what

Answer 12

Rain required to facilitate sperm transfer-> raindrops strike and rupture the sterile jacket, releasing spores

Raindrops containing spermatids cells bounce off and land on the top of a female plant-> spermatids will swim down the archegonium and fertilize the egg

Question 13

Moss zygote is protected how

Answer 13

By archegonium and nourished by the female gametophyte-> grows into undifferentiated ball of cells termed an embryo

Embryo differentiated into a diploid sporophyte

Question 14

Moss Sporophyte reply on what to stay alive

Answer 14

The gametophyte

Supplies nutrients by passing through transfer cells in the placental layer between the gametophyte and sporophyte

Question 15

Upper part of the archegonium of mosses as a cap-like _____

Answer 15

Calyptra

Question 16

What is the main body of the sporophyte and the organ in which spores are produced in mosses?

What are its parts?

Answer 16

Capsule

Sporogenous layer
Columnella
Peristome teeth
Operculum

Question 17

Class sphagnopsida characteristics

Answer 17

-stems of gametophytes bear clusters of branches
-gametophytes arise form a plate like protonema instead of filamentous
-leaves lack midrib and mature plants lack rhizoids
-large hollow cells with many pores called hyaline cells allow direct entry of water
-chlorophyllous cells have many chloroplasts
-dead decay (peat)

Question 18

Economic use of peat

Answer 18

1% of earths surface is peat bogs

Store huge amount of carbon and so may mitigate the effects of anthropogenic climate change

Question 19

Class Bryopsida characteristics

Answer 19

-95% of moss species
-ring of teeth surrounding the mouth of the sporophyte capsule
-changes in misfire conditions cause movements of the peristome and facilitate the dispersion of spores in favourable dry conditions