Plant evolution Flashcards
1
Q
Archeaplastida types and definition
A
Rhodophyta, glaucophyta, viridiplantae(all monophyletic)
Only group with primary plastidd
2
Q
Types of viridiplantae
A
Chlorophyta, streptophyta, charophyta, embryophyta
3
Q
Viridiplantae critical innovations
A
Chlorophyll a+b and storing extra energy as starch(symplesiomorphy)
4
Q
Where did the mitochondria and chloroplast come from?
A
mitochondria: oxygenic photosynthetic bacteria
Chloroplast: cyanobacteria
5
Q
Archeaplastida subgroups characteristic
A
monophyletic
6
Q
Glycogen
A
Short term energy storage, stored in liver+muscles
7
Q
Chlorophyta
A
- Single-celled, green algae
* Haploid dominant reproduction
8
Q
What transition also occurred as life moved from water to land?
A
Haploid dominant(zygotic) to diploid dominant(gametic)
9
Q
Isogamy
A
Same size sex cells(symplesiomorphy)
10
Q
Iteropaurous
A
Multiple chances at reproduction
11
Q
Semelparous
A
One chance at sexual reproduction
12
Q
Cellulose
A
Glucose polymer, strong, gives plant cell shape, no animal can make an enzyme that can break it down
13
Q
What is ER responsible for?
A
lipid+protein production
14
Q
Charophyceans
A
- division of green algae
- paraphyletic group
- first land plants came from this group
- 2 derived, symplesiomorphic traits came from this group: rosette proteins and phragmoplasts, both critical for life on land
15
Q
Phycoplast
A
Microtubules are parallel to plane of division, no connections between daughter cells
16
Q
Phragmoplasts
A
microtubules are perpendicular to plane of division, daughter cells are connected
17
Q
Rosette proteins
A
- Deposit cellulose fibers that form cell wall
- Horizontally placed around cell
- Allow for lengthening of cells
18
Q
What did formation of rosette proteins and phragmoplasts lead to?
A
- cell to cell communication
- Different cellulose pattern, cell shape, form and function
- Tissue differentiation/specialization
- Apical meristems
- Branching
- Reproductive structures
- Gametophytic iteroparity(parents keep reproducing)
19
Q
What did storing energy lead to in plant evolution?
A
More specialization, more likely to survive rough times
20
Q
Purpose of having plasmodesmata+proteins
A
communication
21
Q
Together, what did phragmoplasts and rosette proteins lead to?
A
Communication, altered pattern of of cellulose(cell shape), and tissue differentiation/specialization
22
Q
Components of the tissue differentiation and specialization of plants
A
- Apical meristems
- Branching
- Reproductive strucutures
- Gametophytic iteroparity
23
Q
Apical Meristems
A
Localized regions of growth in plants, 2 types: root and shoot apical meristems,
24
Q
How did sexual reproduction cycles transitioned as plants transitioned from water to land?
A
zygotic meiosis to alternation of generations
25
Indeterminate growth
The type of growth plants perform. It is growth from the tips, where only cells in specialized regions divide
26
Advantage of indeterminate growth/apical meristems
plants are able to grow very large using this method
27
Disadvantage of indeterminate growth/apical meristems
Makes plant a larger target, loss of a small portion of vulnerable tissue can be fatal to the plant
28
Advantages of branching
increased surface area for photosynthesis, a plant can lose a branch and live, more specialization, more energy for future innovations, more offspring
29
Disadvantage of branching
higher energy cost, diffusion of water
30
isogamy
reproduction with equal sized gametes
31
Oogamy
reproduction with gametes where one gamete is bigger than the other
32
Oogamy advantage
more energy/nutrients for zygote, land plants evolved to use Oogamy
33
Oogamy disadvantage
More energetically expensive
34
Gametangia
components that make gametes
35
Reproductive strucutures/tactics evolved by plants
1. Gametangia
2. Archegonia
3. Anthiridia
4. Oogamy
36
Effects of evolution of reproductive structures in plants
Zygote retained/protected, increased parental investment
37
gametophytic semelparity
Gametes fuse and parental generation disappears
38
Sexual reproduction cycle of charophytes
zygotic meiosis
39
What did streptophytes lead to?
embryophytes
40
Charophyceans
Paraphyletic streptophyte group, cellulose, chlorophyll a+b, plastids starches, haploid dominant, aquatic, disc shape(multicellular haploid body)
41
Advantage/disadvantage of charophycean disc shape
gives more surface area in water, bad on land because it would dry out
42
Biggest challenge in transitioning from water to land plants
getting water on land
43
How do we know bacteria moved to land before plants?
only bacteria can fix nitrogen, no plant can
44
What organisms moved to land after plants?
animals
45
Cuticle
Made of Cutin+waxes, transparent, absorbs UVB rays, barrier for water loss, energetically expensive, impacts gas exchange
46
Stroma
open and close to allow for gas exchange, guard cells swell(open) and compress(close) based on water pressure in vacuole
47
Delayed meiosis
produces 4 haploid spores with zygotic meiosis(doubling of population each generation), each haploid can for a new haploid adult, zygote undergoes mitosis instead of meiosis right away, emerged from zygotic meiosis
48
What distinguishes alternation of generations from zygotic meiosis?
multicellular diploid generation
49
Where do cells undergo meiosis to form haploid cells?
embryo
50
sporophyte
multicellular diploid phase
51
Delayed meiosis sequence
zygote under goes mitosis to form multicellular diploid, multicellular diploid undergoes meiosis to form haploid spores, haploid spores undergo mitosis to form multicellular diploid, post fertilization, zygote is in archegonium of the haploid tissue(gametophyte)
52
How did formation of the ozone layer affect movement of plants to land
it filtered uv light and warmed the earth, helping plants move to warm
53
Zygotic meiosis
post fertilization, zygote is in the archegonium of the haploid tissue(gametophyte), 4 spores form
54
Sporangium
Layer of diploid tissue encasing part of the sporophyte that will undergo meiosis to produce a mass of spores, bursts open when spores are released and sporangium dies
55
What type of reproduction did acheaplastids and their ancestors use?
They all used zygotic meiosis, except for embryophytes, they used alternation of generations(synampomorphy)
56
Which plants are members of archeaplastida?
red+green algea, plants
57
What were zygotes of early land plants like?
embryo attached to multicellular haploid body
58
Gametophyte/sporophyte relationship and comparison
Gametophyte is bigger and photosynthetic, sporophyte depends on gametophyte
59
Advantage of delayed meiosis
it produced thousands of offspring as opposed to just 4
60
Bryophytes
small, cuticles, delayed meiosis, stoma, non vascular, land plants, haploid dominant, first land plant lineage, embryo becomes the 2n sporophyte, protected and produced lots of offspring(spores), group of embryophytes
61
Why were/are some plants small?
they relied on diffusion
62
Benefit of being a diploid organism
diploid organisms have 2 copies of each gene, 1 can be a backup
63
What was the purpose for upright 2n stage in bryophytes?
It allowed for dispersal of spores
64
Sporophytes of bryophytes
semelperous(dies when it opens), parasitic, depends on gametophyte, not photosynthetic, no branches(limited growth), covered in cuticle, 2n, bulbous ends to the plant
65
Sphagnum
absorbant, acidic, antibacterial, used as wound dressing
66
Tracheaphytes
followed bryophytes, branching, diploid dominant, shifted from gametophyte dominant to sporophyte dominant, some branches are photosynthetic+specialized, some disperse spores, vascular
67
Vascular tissue
lignin(wood) in cell walls, lead to tissue specialization, not photosynthetic, xylem and phloem
68
Diploid dominant advantage
more water available, sporophyte can get big because it has structural support, more efficient cooling, more UVB tolerance
69
Seedless vascular plants characteristics
Paraphyletic group, lycopods, leaf like strucutures, dominant group was massive trees
70
Evolution of leaves in plants
analagous, major adaptation for life on land, veins
71
What plant group do red algae belong to?
Rhodophyta
72
Groups of acheaplastida
Rhodophyta, glaucophyta, viridiplantae
73
What is necessary for multicellularity and how was it achieved in plants?
1. Cell to cell communication via phragmoplast+plasmodesmata
2. Tissue differentiation
3. Altered cell shape for different functions via rosette proteins
74
Difference between sporophyte and embryo
Embryo is only present in delayed meiosis and sporophyte is present in delayed and normal meiosis
75
Seedless vascular plants innovations
Branching, vascular tissue(lignin), diploid dominance
76
Difference between grouping of lycophytes and pteridophytes
Pteridophytes are seedless vascular plants AND euphyllophytes, Lycophytes are just seedless vascular plants
77
Leaves arose from which type of evolution?
analogous/convergent
78
Benefits of leaves
more surface area, more photosynthesis, more carbon, more energy available to spend
79
Megaphylls vs microphylls
Megaphylls: multiple veins, seen in gymnosperms and angiosperms, increases photosynthesis, derived from branch system
Microphylls: single vein
80
Euphyllophyta
true leaf plants
81
Origin of megaphyll
3D branching▶️overtopping▶️plantation of lateral branches▶️webbing with ground tissue between branches
82
Advantage of overtopping
Larger space occupied, more surface area
83
pteridophyta characteristics
ferms, diverse, highest number of species yet, many different morphologies
84
Seed plant innovations
true leaves, seed, heterospory, ovules, seeds
85
Homospory and heterospory
Homospory: Single spore produced a gametophyte that is bisexual via mitosis
Heterospory: (sympleisiomorphy) spores already have a sexual expression, mega/microsporangia, arose from convergent evolution. Some lycopods/pteridophytes or heterosporous, ALL seed plants are heterosporous
86
Megasporangium
(female) Produces spores by meiosis that use mitosis to germinate and divide, forming a multicellular megagametophyte that will have an archegonia where eggs will develop
87
Microsporangium
Produces spores by meiosis that will germinate and divide by mitosis to form a multicellular microgametophyte that will have antheridia where sperm will develop
88
Advantages/disadvantages of heterospory
More offspring, more energetically expensive(leaves help this)
89
Ovule
Retained, integumented megasporangium
90
Pollen grain role in sexual plant cycles
microgametophyte, multicellular haploid generation
91
How did reproductive cycles change as a result of heterospory?
Sporophyte generation is dominant, gametophyte is retained, microgametophyte is the only gametophyte released
92
Seeds
Point in plant evolution where sporophyte generation becomes completely dominant, contains embryo and resources, gametophyte relies on sporophyte, major innovation
93
Flowers
angiosperms, shortened stems with modified leaves, extreme variation due to co evolution with pollinators and seed dispersal agents
94
Angiosperm definition+innovations
Flowering plants
Innovations: flowers, carpel, pollen tubes and fruitd
95
Orange plastids
chromoplasts full of caretenoids in flowering plants
96
Flowering plant characteristics
Orange plastids, vacuoles full of red, pink and purple anthocyanins, cone shaped epidermis cells(velvety appearance)
97
Carpel
* aka pistil
* additional protective layer around ovules/integuments
* modified leaves
* Fuse to form more complex pistils
98
How is the megasporangium reached through the ovule and carpel?
Pollen lands on liquid drop and grows a tube to the megasporangium and two nuclei are discharged into the embryo sac where double fertilization occurs to form a diploid zygote
99
Fruit
After fertilization the ovule develops into the seed and the pistil into the fruit. They have a lot of variation
100
Berries
single flower with one ovary
101
What do all charophyceans have and what do some charophyceans have?
They all have: cellulose-rich wall, chlorophyll a+b, starch produced in plastids
Some have: Plasmodesmata, sexual reproduction
102
stretophyte innovation
cellulose in cell walls
103
What lead to embryophytes
charophytes/streptophytes and their innovations
104
What allowed gametic iteroparity
Archegonia/antheridia
105
What produced spores?
sporangium
106
Xylem/phloem
Xylem: moves water up plant
Phloem: moves sugar down plant
107
What plants have micro/megasporangia and which plants have antheridia/archegonia?
micro/megasporangia: flowering plants
archegonia/antheridia: other plants
