Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Diversity of life B > Week 4 - Evolution and diversity of pants 1 > Flashcards

Week 4 - Evolution and diversity of pants 1 Flashcards

(64 cards)

Start Studying
1
Q

Name the 5 major plant groups in order of appearance

A

1.Bryophytes
2.Vascular plants
3.Gymnosperms
4.Angiosperms
5.Grasses

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

What caused the Co2 conc to be so high 500mya?

A

A period of intense volcanic activity

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

Simply explain the long carbon cycle, starting with no plants:

A
  1. No plants
  2. Volcanic CO2 outgassing
  3. CO2 in atmosphere combines with rain forming carbonic acid
  4. Carbonic acid causes weathering of rocks
  5. Calcium carbonate runs off rocks into rivers
  6. CO2 ends up in buried in the sea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which were the first land plants?

A

Bryophytes

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

How did bryophytes contribute to the carbon cycle?

A

Chemically = by secreting organic acid
Physically = By penetrating rocks, & expanding

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

What is the primary mechanism for carbon being removed from the atmosphere?

A

Weathering;
Slightly acidic rainwater reacts with silicate or carbonate rocks (like basalt or limestone) during chemical weathering.

The reaction removes CO₂ from the atmosphere

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

When did vascular plants roughly appear?

A

350 mya

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

What did the evolution of a lignified vascular system do for plants?

A

Meant they could increase in size and occupy drier habitats

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

What contributed to the rise of vascular plants?

A

A drop in CO2 levels

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

What are some minerals plants require for growth?

A

Phosphorus, potassium, calcium, magnesium and iron

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

Why was the evolution of a rooting system beneficial for plants?

A
  • Better anchorage
  • Accelerated uptake of nutrients and water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What caused global cooling (glaciation) around 300 mya?

A

Vascular plant activity drew down CO₂, led to carbon burial - less CO2 = cooler

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

Why did the Gymnosperms (seeded plants) emerge?

A

Pangea movement led to a drier climate - more suitable for seeded plants

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

What evidence was there for a drier world?

A

Lower coal deposits imply reduced rainfall

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

When did Angiosperms (flowering plants) emerge ?

A

Around 200 mya prior to this global temperatures were very variable

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

Currently we have 9 biomes, how many did we have 50 mya?

A

5

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

How did the creation of mountains impact CO2 levels and photosynthesis?

A

CO2 levels declined causing C4 photosynthesis to emerge in response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What event led to the production of a plastid (e.g. a chloroplast)?

A

Endosymbiotic events:
A eukaryotic cell engulfed a photosynthesizing cyanobacteria- giving rise to:
- The chloroplast
- The photosynthetic green algae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Is green algae uni or multicellular ?

A

Unicellular but forms colonies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 2 major groups of green algae?

A

Charophyta and Chlorophyta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which chlorophyl does green algae have ?

A

a and b

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which group of algae did land plants originate from?

A

Charophyte algae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the clade called encompassing all green algae and land plants?

A

Chloroplastida

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the clade called encompassing only charophyta green algae and land plants?

A

Streptophyta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is a diplontic life cycle?
Typical animal life cycle The main dominant stage is diploid - multicellular Meiosis leads to production of gametes
26
What is a Haplontic life cycle?
Green algae and fungi Main dominant stage is haploid - multicellular The zygote undergoes meiosis
27
What is a haplodiplontic life cycle?
Includes haploid and diploid phases - both multicellular Meiosis produces spores
28
What are the earliest fossils of land plants we have found?
Spores
29
What are some challenges of transitioning to land ?
Greater UV exposure Water availability varies Higher temperatures
30
How did plants adapt to accessing water on land?
Had rhizoids - thin root like structures that draw water out of a substrate Had primitive water conducting tissues
31
How did plants adapt to conserve water and protect themselves from UV?
Waxy cuticle Sporopollenin
32
What did plants form in order to exchange gas?
Stomata
33
Water is needed for green algae to reproduce?
Water Called oogamous reproduction (immobile female gamete is fertilized by a motile male gamete)
34
Which kind of life cycle to bryophytes have?
Haplodiplontic
35
In the bryophyte lifecycle what does meiosis produce?
Spores
36
What were the 3 early land plant groups?
Hornwort Liverwort Moss
37
What does the gametophyte look like in each early land plant group ?
Hornwort - thallus, unicellular rhizoids Liverwort - thallus, thin cuticle, simple Moss - leafy
38
What does the sporophyte look like in each early land plant group ?
Hornwort - photosynthetic with cuticle and stomata Liverwort - very reduced Moss - simple, non-photosynthetic, stomata in capsule
39
What are some limitations of bryophytes?
Are dependent on substrate and water Gametophyte is dominant - restrict moss ability to grow, spread and reproduce
40
What plants fall within the Tracheophytes?
Lycophytes Ferns and allies Gymnosperms
41
What are tracheophytes?
Plants with tracheids/xylems
42
What are some living groups of vascular plants?
Lycophytes (club mosses) Euphyllophytes- plants with true leaves (seed plants, ferns)
43
What are the innovations of vascular plants?
Vascular tissue (tracheids) Stem - branching of sporophyte Roots - for structure and water absorption Leaves
44
What is a Stele?
An arrangement of vascular tissues in stem - with a hollow middle
45
What is the difference between a protostele and a siphonostele?
Protostele contains: Vascular tissues form a solid mass in centre of stem. Epidermis Cortex Phloem & Xylem Siphonostele contains: Vascular tissues form cylinder around central pith. Epidermis Cortex Phloem & Xylem AND A PITH
46
What type of stele does a lycophyte have?
Protostele
47
What type of stele does a fern have?
Siphonostele
48
What is a Eustele and what plant has it ?
Vascular tissues in bundles around hollow pith. Horsetail
49
What are rhizomes?
Underground stems
50
What are the 2 main structures of leaves?
Microphylls and Megaphylls
51
How do Microphylls and megaphylls differ?
In microphylls : The mesophyll colour is the same on both sides. Has a single middle vein In megaphylls: The mesophyll colour is different on each side The stomata is on the underside of the leaf Have branching veins
52
What is the lycophyte's gametophyte and sporophyte like?
Has a dominant, branching sporophyte and a small free-living gametophyte.
53
What spores do lycophytes produce?
Specialised leaves bear spores that can be homosporous or heterosporous
54
What are some vascular plant reproductive innovations?
Has dominant sporophyte Heterospory = the ability to produce 2 spores (mega and micro)
55
Are bryophytes homosporous or heterosporous?
Homosporous
56
What are the 2 phases of a Selaginella life cycle?
1. A diploid sporophyte phase - which produces micro and mega spores 2. A haploid gametophyte phase - produces sperm and eggs for fertilisation
57
What is endosporic development?
The megagametophyte or female gametophyte is very reduced and develops inside the megaspore.
58
What are advantages of heterospory?
- More nutrients for fewer bigger spore - Greater dispersal of microspores - Production of separate gametophytes - Endosporic development: protection of megagametophyte in megaspore
59
What is the basic structure of a seed?
The EMBRYO is in the middle, and surrounded by food storage tissue called the NUCELLUS. The seed coat surrounds the nucellus
60
Where is the Nucellus derived from?
The megasporangium
61
How did the seed evolve?
Early plants used spores 1. Then heterospory evolved - microspores - megaspores 2. Megaspores were retained in the parent plant (megasporangium) for protection and nutrients. 3. Megaspore develops within the megasporangium (nucellus) 4. A megasporangium became surrounded by protective layers of tissue called integuments. 5. Ovules evolved 6. Seed formation
62
What is the Ovule formed of ?
Integuments + megasporangium + megaspore
63
What are advantages of the seed?
- Sporophyte embryo is protected - Food supply for developing embryo - Dispersal - Dormancy – next gen is delayed until favourable conditions
64

Diversity of life B (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions