Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biodiversity > Lecture 2: Origin of land plants: hidden world of bryophytes > Flashcards

Lecture 2: Origin of land plants: hidden world of bryophytes Flashcards

1
Q

Bryophytes basics

A
  • most basal form of land plants
  • share common ancestor of ancestral green algae
  • first land plants. although first land plants there are some still present today b’cos so basal and adapted.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Reproductive strategy of bryophytes

A

homosporous reproductive strategy. With the Gametophyte the dominant phase of the life cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Steps for reproduction of bryophyte

A

1) Gametophyte produces both egg and sperm
2) sperm swims over to egg
3) Forms a sporophyte
4) Meiosis occurs resulting in haploid cells again
5) cycle repeats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is necessary for reproduction and WHY

A

WATER for sperm to move to egg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

During reproduction the ________ is dependent on the _______ for nutrition. Sporophyte is ____ lived and the Gametophyte is the _____ stage.

A

sporophyte
Gametophyte
short
dominant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Characteristics of living Bryophytes: heterosporous or homosporous?

A

homosporous - producing asexual spores of old one type

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Characteristics of living Bryophytes: sex organs have

A

a sterile jacket. Egg cells enclosed in a single flask-shaped archegonium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Archegonia?

A

multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female gamete

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

antheridia?

A

Male sex gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

zooidogamous?

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Characteristics of living Bryophytes: their sperm!

A

• Spermatozoids zooidogamous with two whiplash flagella (sperm have two flagella, required for swimming to egg)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Characteristics of living Bryophytes: type of embryogeny

A

Embryogeny exoscopic (way the organism grows)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

isospore?

A

asexual spore = spore which does not arise through sexual reproduction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Characteristics of living Bryophytes: what does the sporophyte produce

A

numerous isospores (same size) enclosed in a protective sporopoellenin wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

gemma (plural gemme)?

A

a single cell, or a mass of cells, or a modified bud of tissue, that detaches from the parent and develops into a new individual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Characteristics of living Bryophytes: capable of vegetative propagation?

A

Some are of the gametophyte by fragmentations or specialised gamma (sexual and non-sexual reproduction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Growth form of Bryophytes

A
  • Generally v small (soft as no lignin present)
  • Gametophyte either
    - thallus flattened with some internal gametophyte differentiation
    - main axis with leafy appendages
  • The thallus bears rhizoids - but no roots
  • some have primitive water conducting cells - but these are NOT lignified
18
Q

rhizoid

A

root like filaments

19
Q

how are the spores dispersed?

A

widely dispersed by wind and they have colonised most of the planet

20
Q

are they able to survive in cold and dry environments?

A

yes as have the ability to lose most of their body water without dying, then rehydrate and reactivate their cells when moisture again becomes available

21
Q

dependant on what for reproduction?

A

free water - movement of sperm

22
Q

what sort of plant are they?

A

Colonisers of bare rock and soil surfaces (primary colonisers - e.g. Sertsey)

23
Q

What allows them to survive in desert, high altitudes (mountainous regions) and high latitudes (polar regions)

A

Phenolic compounds in cell walls protects against UV radiations

24
Q

They are epiphytes what does this mean?

A

grows harmlessly upon another plant. Doesn’t necessarily negatively affect host, grow or physical support

25
Q

why are sphagnum bogs useful?

A

removes CO2 form atmosphere, holds lots of water

26
Q

liverworts definition:

A

a small flowerless green plant with leaf-like stems or lobed leaves, occurring in moist habitats. They lack true roots and reproduce by means of spores released from capsules.

27
Q

protonema:

A

thread like chain of cells that form the earliest stages of a bryophyte life cycle. First growth from the spore and develops into Gametophyte
(•The protonemal phase of the gametophyte is usually ill defined).

28
Q

thallus:

A

a plant body that is not differentiated into stem and leaves and lacks true roots and a vascular system. Thalli are typical of algae, fungi, lichens, and some liverworts.

29
Q

Gametophyte thallus of liverwort:

A

may be thalloid or leafy but the mature thallus usually shows dorsiventrality

30
Q

dorsiventrality:

A

extension along an axis joining the dorsal and ventral surfaces

31
Q

Leaf shapes on liverworts

A

Leafs may be simple more-or-less circular plates of cells or lobed (twice or several times)

32
Q

In leafy liverworts the stem is..

A

inclined or lying flat down with dorsiventral symmetry

33
Q

characteristic feature of liverwort gametophyte:

A

is the presence of oil bodies in the cytoplasm

34
Q

how are leave usually arrange din liverworts?

A

in 3 ranks, but only those on the dorsal side are full developed

35
Q

dorsal side means

A

surface of an organ or part facing away from the axis

36
Q

antheridores and archegoniophores:

A

Some species have complex antheridia/archegonia where male and female gametes are produced on upright umbrella-shaped structures termed antheridiophores and archegoniophores respectively. They develop from one half of a dichotomy (division into two parts).

37
Q 
EVOLUTIONARY HISTORY OF THE BRYOPHYTES:
Mid Ordovician (475 Ma)
A

The first land plants evolves from an aquatic green algal ancestor. Fossil evidence is in the form of dispersed spores identical (in terms of morphology and ultrastructure) to those of extant bryophytes. The three major groups of bryophytes (liverworts, mosses, hornworts) diverge early. The plants are v. small with the gametophyte dominant and homosporous reproduction when the subsidiary sporophyte appears. The vegetation is widespread but confined to damp environments.

38
Q 
EVOLUTIONARY HISTORY OF THE BRYOPHYTES:
Early Silurian (435 Ma)
A

Tracheophytes (vascular plants) evolve. They outcompete the bryophytes and rapidly diversify. Bryophytes persist but as an inconspicuous element of the vegetation confined to harsh and unstable damp environments that the tracheophytes cannot inhabit.

39
Q 
EVOLUTIONARY HISTORY OF THE BRYOPHYTES:
Mid Devonian (380 Ma)
A

The first trees evolve and forests form. Bryophytes rediversify as they discover a new niche they can exploit: as epiphytes on trees.

40
Q

Commercial use of bryophytes:

A
  • seed fuel
  • fuel
  • absorbant bandages

Biodiversity (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions