Plant diversity Flashcards
1
Q
When did Cyanobacteria emerge? When did the others join?
A
1.2 billion years ago
Other fungi, algae, “plants” joined ~700 million years ago
2
Q
Where is the earliest evidence of trees?
A
Earliest evidence of trees in Megouasag (Micmac for “red cliffs”)
Archaeopteris is a historical tree
Fossil beds are ~380 million years old
Development of lignin allowed for super rigid cell walls to support upward grow
Had fern-like leaves -> surface area allowed more efficient photosynthesis to compete with early plants
3
Q
What are plants apart of?
A
are part of Archaeplastida
Unicellular, multicellular and/or colonial members
4
Q
What are the 2 main clades of Archaeplastida ?
A
Green algae (paraphyletic because 2 main groups charophytes and other one) Red algae (monophyletic) -> have a holdfast, stipe(stem), blade (leaf)
Use of photosynthetic pigments allows for the adaptation to different environments and also identifies members
5
Q
What did plants evolve from
A
Plants evolved from green algae
Green algae called charophytes are the closest relatives of plants.
6
Q
Which traits in algae and plants?
A
Some of these traits were acquired independently and tell an incomplete story with respect to the origin of plants
Multicellularity
Photosynthetic pigments (i.e. chlorophylls)
Cell walls composed of cellulose
7
Q
Charophytes
A
(Supergroup Archaeplastida, Green algae) are closest relatives to terrestrial plants
8
Q
What evidence supports that charophytes are the closest relatives to plants?
A
- Rings of cellulose-synthesizing proteins (in other algae and plant organisms the cellulose forming proteins occur linearly)
Many algae produce cellulose in cell walls,but charophytes and land plants have distinctive circular rings of proteins in the plasma membrane - Flagellated sperm
In plant species that have flagellated sperm, they most resemble the sperm in charophytes compared to other algae - Formation of phragmoplast
Microtubules and associated proteins present in charophytes and land plants after cytokinesis, guiding the assembly of cell plate formation
• Molecular analyses of nuclear, mitochondrial and chloroplast DNA also support this
9
Q
What are the benefits of moving to land?
A
Moving to land is beneficial: (unlimited Co2 nutrients from soil more light)
• Sporopollenin is a polymer that prevents desiccation (Common in charophytic algae living at the edge of shallow ponds)
• More unfiltered sunlight, carbon dioxide, nutrients in soil -> life is good!
10
Q
What are the challenges of moving to land?
A
Water is scare, harder to disperse sperm
• Have to grow against gravity
11
Q
Sporopollenin
A
A durable polymer that covers exposed zygotes of charophyte algae and forms the walls of plant spores, preventing them from drying out
adaptation for life on land
12
Q
What are some adaptations of plants to allow for survival on land?
A
Accessory pigments to help with UV protection, antioxidant effects
Cuticle -> waxy layer on the outer epidermis to help prevent desiccation
Stomata (pores) -> allow exchange of carbon dioxide and oxygen (photosynthesis is efficient even more because you have regulated gas exchange)
(Can close in periods of hot, dry conditions to prevent water loss )
Formed symbiotic relationships with fungi (roots did not immediately
happen) with mycerizae
Developed meristems to allow for vertical growth
Alternation of generations life cycle
Analysis of fossilized spores shows plants colonized land ~450 million years ago
13
Q
Stomata
A
A microscopic pore surrounded by guard cells in the epidermis of leaves and stems that allows gas exchange between the environment and the interior of the plant.
14
Q
Cuticle
A
A waxy covering on the surface of stems and leaves that prevents desiccation in terrestrial plant
15
Q
How can plants be classified?
A
Plants can be broadly classified based on the presence of vascular tissues
16
Q
vascular tissue
A
Plant tissue consisting of cells joined into tubes that transport water and nutrients throughout the plant body
17
Q
What do non vascular plants include?
A
(bryophytes)
Liverworts
Mosses
Hornworts
18
Q
What can vascular plants be divided into
A
comprises about 93% of all extant plant specie
Seedless vascular plants
Seedplants
19
Q
What do Seedless vascular plants include?
A
Lycophyta (club mosses, spike mosses, quillworts
Monilophytes (ferns, horsetails, whisk ferns
20
Q
What do Seedplants include?
A
Gymnosperms (ginkgos, cycads, gnetophytes, conifers)
Angiosperms (flowering plants)
21
Q
Seedless vascular plants
A
An informal name for a plant that has vascular tissue but lacks seeds. Seedless vascular plants form a paraphyletic group that includes the phyla Lycophyta (club mosses and their relatives) and Pterophyta (ferns and their relatives).
22
Q
Which phylum has the most species?
A
Angiosperms
23
Q
What is an example of a grade?
A
A group, such as the bryophytes or seedless vascular plants, is sometimes referred to as a grade
monilophytes and lycophytes
24
Q
What are the monilophytes closely related to?
A
even though monilophytes and lycophytes are all seedless plants, monilophytes share a more recent common ancestor with seed plants
As a result, we would expect monilophytes and seed plants to share key traits not found in lycophyte
25
seed
An adaptation of some terrestrial plants consisting of an embryo packaged along with a store of food within a protective coat.
26
gymnosperms
A vascular plant that bears naked seeds—seeds not enclosed in protective chambers.
27
angiosperms
A flowering plant, which forms seeds inside a protective chamber called an ovary
28
herbaceous
non woody liverworts (phylum Hepatophyta), mosses (phylum Bryophyta), and hornworts (phylum Anthocerophyta).
29
Describe the general life cycle of plants
1) Gametophyte produces haploid gametes (1n) via mitosis
2) Two gametes (1n) come together via fertilisation to produce a diploid zygote (2n)
3) The zygote (2n) develops into the multicellular sporophyte
4) The sporophyte (2n) produces unicellular haploid spores (1n) by meiosis
5) The spores (1n) develop into multicellular haploid gametophytes (1n
30
What are liverworts and hornworts named for?
Liverworts and hornworts are named for their shapes, plus the suffix wort
31
ii
Phylogenetic analyze suggest bryophytes diverged early in plant lineage evolution
Earliest spores of plants (450-470 million years ago) more similar to liverwort spores (most basal group)
~430 million years ago spores similar to mosses and hornworts showed up in the fossil record
32
What stage is dominant in bryophytes?
Bryophytes have a dominant haploid stage
gametophyte stage
they are usually larger and longer-living than the sporophytes
33
gametophyte
```
In organisms (plants and some algae) that have alternation of generations, the multicellular haploid form that produces haploid gametes by mitosis. The haploid gametes unite and develop into sporophytes.
(gamete producing bodies)
```
34
Protonema
threadlike filaments that develop into “buds” which grow via a meristem to produce the gametophores
35
Gametophore
“gamete bearer”, produces gametes via mitosis
36
Rhizoids
“root-like” filaments that anchor the gametophyte (not true roots)
37
Gametangia
produces the gametes
38
Archegonia
female, produces the egg
39
Antheridia
male, produces sperm
40
sporophytes
(spore producing bodies)
| Bryophytes have the smallest sporophytes
41
Seta
stalk supporting the sporangium
42
Foot
absorbs nutrients from the gametophyte, supports the seta
43
Capsule
sporangium, produces spores via meiosis
44
Peristome
“teeth” on the capsule to regulate spore dispersal (open when its wet enough let some spores and close when its too dry)
45
Describe the bryophyte life cycle
1) Spores (1n) develop into threadlike protonema
2) Protonema (n) produces “buds” the develop into gametophytes (n)
Gametangia
Antheridia -> male, sperm
Archegonia -> female, egg
3) Sperm must swim through water to reach the egg (Gametes produced via mitosis) (need access to water for fertilization)
4) Zygote develops into a sporophyte embryo (2n)
5) Sporophyte grows a seta that emerges from the archegonium
6) Attached by the foot, the sporophyte (2n) remains nutritionally dependent on the female gametophyte (n)
7) Meiosis occurs in the 2n capsule, producing spores
46
Describe bryophytes
Common in moist forests and wetlands, moist bare soil
Many associate with nitrogen-fixing bacteria
Can survive harsh environments (cold, dry)
Some Sphagnum moss species comprise peat
Many bryophyte species also have a medicinal or cultural importance in many Indigenous nations
(Bandages for wounds, baby diapers)
47
Why are bryophytes ecologically important?
* Help retain moisture
* Help retain nitrogen within the environment
* Can tolerate complete water loss and can re-establish when moisture returns -> poikilohydric
Some Sphagnum moss species comprise peat
Preserves organisms from decaying due to the low temps, pH, and oxygen levels of peatlands
Important fuel source (Finland and Ireland uses a lot of it!)
Horticultural nutrient to help retain moisture in soils
Carbon sink -> 30% of the world’s carbon is stored in peatlands comprising 3% of Earth’s surface
48
What were seedless vascular plants the first to do? When did they arise?
First to grow tall due to the rigid structure of vascular tissues
Arose ~425 million years ago
49
Compared to nonvascular plants, Seedless vascular plants had:
* Branched sporophytes now dominant stage
* Not nutritionally dependent on the gametophyte
Still lack true roots
Vascular tissues
Xylem -> water transport, structural support
Phloem -> nutrient transport
50
Xylem
water transport, structural support Vascular plant tissue consisting mainly of tubular dead cells that conduct most of the water and minerals upward from the roots to the rest of the plant.
51
Phloem
nutrient transport
Vascular plant tissue consisting of living cells arranged into elongated tubes that transport sugar and other organic nutrients throughout the plant.
52
Describe the fern life cycle
1) Sporangia release spores (n). Spores develop into a bisexual photosynthetic gametophyte antheridia and archegonia are produced on the same plant
2) Each gametophyte (n) produces antheridia and archegonia via mitosis. Sperm usually fertilizes the egg of another gametophyte
3) Sperm uses flagella to swim to the egg, attracted via positive chemotaxis to the archegonium
4) Zygote (2n) develops into a new sporophyte (2n), which grows out of the archegonium of the parent gametophyte
5) Sporophytes (2n) produce sori, clusters of sporangia (2n) which will produce spores via meiosis
53
What is the xylem composed of?
Composed of tracheids and vessel elements, strengthened by lignin
54
What is the phloem composed of?
Composed of sieve tube elements and companion cells
55
i
Allows plants to grow tall and still get nutrients to leaves
Allows plants to outcompete shorter plants for light
56
tracheid
A long, tapered water-conducting cell found in the xylem of nearly all vascular plants. Functioning tracheids are no longer living.
57
lignin
A hard material embedded in the cellulose matrix of vascular plant cell walls that provides structural support in terrestrial species.
58
Describe the evolution of roots in Seedless vascular plants
Vascular tissues are also found in roots
| Roots absorb water and nutrients from the soil, anchors the plant
59
Describe the evolution of evolution of leaves Seedless vascular plants
```
Leaves increase surface area for photosynthesis
Megaphylls
Microphylls
Shoot system
Root system
```
60
Megaphylls
larger, more evolutionarily advanced
| A leaf with a highly branched vascular system, characteristic of the vast majority of vascular plants
61
Microphylls
smaller, supported by a single strand of vascular tissue (Lycophytes)
In lycophytes, a small leaf with a single unbranched vein.
62
Shoot system
is comprised of the above ground organs of the plant (leaves, stems)
63
Root system
is comprised of the below ground organs
64
Sporophylls
Modified leaves that bear sporangia
65
sori
A cluster of sporangia on a fern sporophyll. Sori may be arranged in various patterns, such as parallel lines or dots, which are useful in fern identification
66
strobili
The technical term for a cluster of sporophylls known commonly as a cone, found in most gymnosperms and some seedless vascular plants
found in lycophytes
67
i
Fern sporophylls produce sori (sing. sorus)
Lycophytes (clubmosses and allies) produce strobili (sing. strobilus), which are little “cones”
Angiosperms (covered later) have modified sporophylls called carpels and stamens
68
Most seedless vascular plants are..
homosporous
69
homosporous
a plant species that has a single kind of spore(One type of sporangium that produces one kind of spore )
develops into a bisexual gametophyte
Ex. Ferns
70
heterosporous
(mosses, all seed plants)
Referring to a plant species that has two kinds of spores: microspores, which develop into male gametophytes, and megaspores, which develop into female gametophytes
71
Megasporophylls
(“female spore leaves”) which produce megasporangia
72
megasporangia
female spore bearing structures
73
Microsporophyll's
“male spore leaves”) which produce microsporangia
74
microsporangia
“male spore bearing structures”)
75
Lycophyta
Clubmosses, spikemosses, quillworts
Most ancient group
Carboniferous period(359-299millionyears ago)
Used to be massive (2m wide!), but changing drier climate meant only the small ones were able to survive
76
Monilophyta
Ferns, horsetails, whisk ferns
Devonian origins
Ferns are most diverse, ~12,000 species
More closely related to seed plants than lycophytes
• Have leaves, roots
~15 species of horsetails exist today (Equisetum spp.)
Whisk ferns (Psilotum sp.) are considered “living fossils”
77
How are seedless vascular plants diverse?
1. Modified leaves allow for reproduction
2. Most seedless vascular plants are homosporous
3. Some seedless vascular plants are heterosporous
78
Spike Moss
Phylum: lycophyta
Habitat: marshy areas or as submerged aquatic plants
Sporophytes: upright stems
Leaves: many small leaves
Types of sporangia: heterosporous
79
Quillwort
Phylum: lycophyta
Habitat: aquatic
Sporophytes: *
Leaves: single sporophyll
Types of sporangia: heterosporous*
80
Club Moss
Phylum: lycophyta*
Habitat: *
Sporophytes: horizontal stems
Leaves: strobili
Types of sporangia: homosporous
81
Fern
Phylum: monilophyta
Habitat: tropical to temperate
Sporophytes: megaphylls
Leaves: large leaves called fronds, often divided into leaflets*
Types of sporangia: most homosporous
82
Horsetail
Phylum: monilophyta*
Habitat: marshy places & along streams*
Sporophytes: vegetative & reproductive stems
Leaves: rings of leaves
Types of sporangia: homosporous with cones releasing spores that typically give rise to bisexual gametophytes*
83
Whisk Fern
Phylum: monilophyta*
Habitat: species of the genus Timesipteris, closely related to whisk ferns are found only in the South Pacific*
Sporophytes: dichotomously branching, lacks roots
Leaves: reduced
Types of sporangia: homosporous
84
Describe the process of Homosporous spore production
sporangium on sporophyll -> single type of spore -> typically a bisexual gametophyte -> eggs OR sperm
85
Describe the process of Heterosporous spore production (all seed plants) FOR EGGS
MEGAsporangium on MEGAsporophyll( -> MEGAspore -> female gametophyte -> eggs
86
Describe the process of Heterosporous spore production (all seed plants) FOR SPERM
MICROsporangium on MICROsporophyll -> MICROspore -> male gamete -> sperm
87
Describe the adaptations of Seed plants
Seeds
Reduced gametophytes (in bryophytes it was obvious in ferns the sporophyte was dominant but gametophyte was still visible)
Heterospory
Ovules and pollen
88
Describe the Reduced gametophytes in seed plants
(in bryophytes the sporophyte is nutritionally dependent on the gametophyte, but in seed plants its other way around)
Microscopic
Tiny gametophytes can develop directly in the sporangium (sporophytes)
( Protection from the elements such as UV radiation, desiccation )
Gametophytes nutritionally dependent on the sporophyte now
89
Most seed plants are...
heterosporous
90
integument
2n Layer of sporophyte tissue that contributes to the structure of an ovule of a seed plant.
(sporophytic tissue that envelopes and protects the megasporangium)
91
What is unique about seed plants?
Seed plants retain the megasporangium within the parent sporophyte
92
How many integuments do gymnosperms or angiosperms have?
Gymnosperms -> 1 integument
| Angiosperms -> 2 integuments
93
Ovule
megasporangium (2n) + megaspore (n) + integuments (2n)
94
where does the female gametophyte develop?
The female gametophyte will develop within the ovule from a megaspore and produces one or more eggs.
95
pollen grain
(n) -> develops from a microspore and contains the male gametophyte enclosed within a pollen wall
Pollen grain ≠ male gametophyte
Inside = male gametophyte (n), outside pollen wall = secrete by microsporocytes (2n), contains sporopollenin
96
Pollination
transfer of pollen to the ovule through a pollen tube in the micropyle of the ovule
97
What can help ID a plant species?
Shape of pollen grains and outer wall spikes can ID
98
What are advantages of pollen grains
can travel large distances without needing to swim in water
99
If a sperm fertilizes an egg,...
zygote will grow into a sporophyte
100
what develops into a seed
, the whole ovule develops into a seed: the embryo, with a food supply, packaged within a protective coat derived from the integument(s).
101
What advantages do seeds provide over spores?
In non-vascular plants, spores could be released in a dormant state that germinates when conditions are good; their small size allows for this
However, spores are a single cell
No food supply
In seed plants, the ovule develops into a multicellular seed, which can remain dormant for longer periods of time
Embryo
Food supply
Protected seed coat (develops from the integument)
102
seed plant history
Seed plants share characteristics that arose during the Devonian period (380 million years ago)
• Archaeopteris was heterosporous, though it did not make seeds
103
When was the first evidence of seed plants recorded?
First evidence of seed plants themselves arose around 360 million years ago based on fossil record
55 million years before Gymnosperms
> 200 million years before Angiosperms
104
Cycads
| Cycadophyta
palm like leaves, large cones
~300species
Have flagellated sperm (suggests descent from seedless vascular plants
Most endangered -> 75% species threatened by habitat destruction
105
Gnetophytes
Gnetum,Ephedra,Welwitchia
Tropical and desert habitats
Welwitschia mirabilis can live 1000s of years, deserts in SW Africa
Ephedra has ~40 spp., desert shrubs
Gnetum has ~35 spp., tropical trees, vines, shrubs in Africa and Asia
106
Ginkgos
| Ginkgophyta:
Ginkgobiloba,“maiden-hair”tree
Have flagellated sperm
Deciduous, fan-like leaves that turn gold in autumn
Tolerant to pollution
Only plant males because female seeds stink as they decay
107
Pinophyta; Conifers
Pines, Spruce, Fir, junipers, larch, sequoia
The largest and most diverse gymnosperm phylum (~600)
Most species have woody cones (junipers have fleshy cones) and are evergreen
Some species are deciduous (larch, tamarack, some redwoods)
Leaves are needle-like (Pines, spruce) or scale-like (redwoods)
Huge economic importance (lumber, chemical compounds (taxol from Pacific yew))
108
Describe the evolutionary history of gymnosperms
Earliest Gymnosperm fossils are ~305 million years old
Lived in moist Carboniferous ecosystems still dominated by lycophyte sand other seedless vascular plants
Survived better in drier climates due to seeds and pollen, thicker cuticles and small surface area of their needles (leaves)
109
What are some things common to all gymnosperms?
Increasing dominance of the sporophyte
Seed as a resistant, dispersible stage in the life cycle
Pollen as an air born eagent brining sperm to the female gametophyte
All are heterosporous
Most produce cones: ovulate cones(female)and pollen cones(male)
• The scales on the cones are specialised sporophylls
Wind is the primary mode of dispersal
110
Describe the pine life cycle
1) In most conifer species, each tree has both ovulate (female) and pollen (male) cones (often occur on the same plant but pollination wouldn’t occur on same plant they would go to different plant)
2) Microsporocytes divide by meiosis to produce microspores (n). The microspore develops into a pollen grain (the male gametophyte (n) + surrounding wall (2n))
3) An ovulate cone scale has 2 ovules, each containing a megasporangium. Only 1 ovule is shown here.
4) Pollination occurs when the pollen grain reaches the ovule, germinating to form a pollen tube that grows through the megasporangium
5) While the pollen tube develops, the megasporocyte (2n) undergoes meiosis. Producing 4 haploid cells. Only 1 survives as the megaspore (n)
6) The megaspore develops into a female gametophyte(contained withing megasporangium) that contains 2-3 archegonia, each of which will form an egg
7) By the time eggs are mature, sperm cells are fully developed and travel down the pollen tube for fertilization (the leftover gametophyte tissue becomes a food source)
8) Fertilization usually occurs 1 year after pollination. All the eggs may be fertilized, but only 1 zygote develops into an embryo (2n).
The ovule becomes a seed (embryo + food supply + seed coat)
111
Angiosperms
“Flowering plants” (seeds are contained within food no longer naked)
112
Dispersal vectors of angiosperms
Wind: common in grasses, temperate tree species
Animals: fruit-eating animals, hummingbirds
Insects: bees, moths, flies
113
flower
In an angiosperm, a specialized shoot with up to four sets of modified leaves, bearing structures that function in sexual reproduction
114
Sepals
outermost whorl of sporophylls; usually green (like on a bud)
115
Petals
showy, inner whorl; attracts pollinators
116
Stamens
microsporophyll's that produce microspores that develop into pollen grains
• Composed of anthers and filaments
117
Carpels
syn.Pistal)->megasporophylls that produce megaspores that develop into female gametophytes
• Composed of the stigma,style,and ovary
118
What can flowers vary in?
Can vary in their symmetry
Can vary in their floral parts (some have decorative stamens, some have 4 petals etc. can help us distinguish the species)
Can be annual (1 year), biennial (every 2 years), or perennial (every year)
119
fruits
ovary wall that has thickened around the seeds
120
What do fruits do?
• Protects the seeds and aids in dispersal
Can be fleshy or dry
Have adaptations to allow for dispersal
121
What adaptations do fruits have to allow for dispersal
Propellers(mapleseeds)
parachutes(Dandelions for wind dispersal)
rough coats to stick to animals (burrs on dogs)
Sweet tasting fruit(so animals eat and poop out the seeds in a new location
122
Describe the angiosperm life cycle
1) In the megasporangium, the megasporocyte divides by meiosis, producing 4 megaspores of only which 1 survives
2) On the anther, each microsporangium contains microsporocytes that divide by meiosis, producing microspores
3) A microspore develops into a pollen grain. The generative cell of the male gametophyte will divide, forming 2 sperm. The tube cell will produce the pollen tube
4) After pollination, eventually two sperm cells are discharged in each ovule
5) Double fertilisation occurs. One sperm fertilizes the egg, forming the zygote. The other sperm fertilizes the central cell, forming a 3n endosperm (food supply)
6) Zygote develops into an embryo that is packaged into the seed with the food supply (fruit not shown)
7) The seed germinates and grows into a new sporophyte (2n)
123
Describe the male gametophyte structure of angiosperms
Prothallial cells -> produce the generative and tube cells
Generative cell -> produces sperm
Tube cell->produces the pollen tube
Exine -> outer wall composed of sporopollenin
124
Prothallial cells
produce the generative and tube cells
125
Generative cell
produces sperm
126
Tube cell
produces the pollen tube
127
Exine
outer wall composed of sporopollenin
128
Describe the female gametophyte structure of angiosperms
Also called the embryo sac
Antipodal cells -> cells at the far end of the gametophyte
Polar nuclei (inside the central cell) -> forms the endosperm following double fertilization
Synergids -> near the egg, aid in fertilization (help direct pollen tube to the egg)
Egg -> female gamete
129
Antipodal cells
cells at the far end of the gametophyte
130
Polar nuclei
inside the central cell) -> forms the endosperm following double fertilization
131
Synergids
near the egg, aid in fertilization (help direct pollen tube to the egg)
132
Egg
female gamete
133
endosperm
In angiosperms, a nutrient-rich tissue formed by the union of a sperm with two polar nuclei during double fertilization. The endosperm provides nourishment to the developing embryo in angiosperm seeds.
134
cotyledons
a seed leaf of an angiosperm embryo
135
Basal Angiosperms
~100)
Water lilies, Star anise and relations, Ambrorella
Oldest Angiosperm linegage
Spiral arrangement of floral parts
136
Magnoliids
(~8000 species)
Magnolias,Laurels,BlackPepperplants(Pipernigrum,plant of the day)
Woody and herbaceous species
Spiral arrangement of floral parts
137
Monocots
(~70,000 species)
• Orchids, grasses ,palms
• Fibrous rootsystem
• Simple leaves with parallel veins
138
Eudicots
~170,000 species)
Legumes, roses, flowering trees (oak, walnut, etc)
Taproot system
Leaf venation is netted
139
Describe Angiosperm Evolution
Widespread appearance in the fossil record (~140 million years ago)
• Originated in the Cretaceous period
• Archaefructus is a fossil angiosperm, with a herbaceous and bulbous growth habit
140
i
One current hypothesis of the phylogeny of Angiosperms is based on morphological and molecular evidence
• Living Angiosperms are monophyletic
• Evolution often was a result of plant-animal interactions
Anti-herbivory compounds, mutualistic co-evolution of animal pollinators
Flower shape and colour can be very specific to pollinator preference
141
What are some characteristics of monocots?
embryos- one cotyledon
leaf venation:veins usually parallel
stems: vascular tissue scattered
roots: root systems usually fibrous (no main root)
pollen: pollen grain with one opening
flowers: floral organs usually in multiples of 3
142
What are some characteristics of eudicots?
embryos- 2 cotyledon
leaf venation: veins usually netlike
stems: vascular tissue usually arranged in a ring
roots: taproot usually present
pollen: pollen grain with 3 openings
flowers: floral organs usually in multiples of 4 or 5
