Plant Diversity Flashcards
1
Q
What are non-vascular plants called?
A
Bryophytes
2
Q
What are the closest relatives of plants?
A
Green algae called charophytes
3
Q
What is some evidence that charophytes are closely related to plants?
A
- Distinctive rings of proteins in cell membrane that synthesize cellulose of cell wall.
- Flagellated sperm of some plants similar to charophyte sperm
- Nuclear, mitochondrial and chloroplast DNA similarity.
- Sporopollenin encasing plant spores and encasing charophyte embryos
4
Q
What are the derived traits of all plants?
A
- Alteration of generations
- Walled spores produced in sporangia
- Apical meristems
5
Q
Are the bryophytes monophyletic?
A
No!
6
Q
What are some functions of mosses?
A
Nutrient cycling (nitrogen)
7
Q
Sporophyte
A
Multicellular, diploid form of plant
8
Q
Gametophyte
A
Structure producing haploid gametes
9
Q
Sporangium
A
Structure where meiosis occurs and haploid spores are produced
10
Q
Archegonia
A
Where female gametes are produced
11
Q
Antheridia
A
Where male gametes are produced
12
Q
What are the six main traits of bryophytes?
A
- Gametophyte dominant
- No vascular tissue
- No roots
- No leaves
- No cuticle
- The sporophyte is attached to and dependent on female gametophyte for nutrition
13
Q
Which two phyla of bryophytes are we focusing on?
A
Hepatophyta (liverworts) and Bryophyta (mosses)
14
Q
List out the steps of the bryophyte life cycle. Indicate which structures are diploid and which are haploid.
A
- Spores develop into thread like protonemata (n).
- Protonemata produce buds that go through mitosis and develop into gametophores giving rise to male/female gametophytes (n).
- Male flagellated sperm(n) leave antheridia (n) and swim through a film of moisture to reach the egg(n) in the archegonium (n), FERTILIZATION OCCURS (n) -> (2n).
- Zygote develops into sporophyte embryo within archegonium (2n).
- Sporophyte grows long stalk (seta) that emerges from archegonium (2n).
- The sporophyte (2n) is attached to the gametophyte (n) by its foot, staying nutritionally dependent on it.
- Meiosis occurs in capsule/sporangium (2n) where spores are produced (n). When capsule is mature, its lid pops off and spores are released.
15
Q
What is the function of rhizoids in bryophytes?
A
Attachment to substrate, NOT absorption.
16
Q
What are the three parts of the bryophyte sporophyte?
A
Sporangium/capsule, seta, foot.
17
Q
What is the function of the sporangium/capsule in bryophytes?
A
To facilitate meiosis so that sporocytes (2n) turn into spores (n)!
18
Q
What is the function of the seta in bryophytes?
A
Dispersal of what idk but its basically an elongated stalk
19
Q
What is the function of the foot in bryophytes?
A
To receive nutrients from the female gametophyte
20
Q
Which bryophyte sporophytes have stomata?
A
Hornworts and mosses
21
Q
Do liverwort sporophytes have stomata?
A
No!
22
Q
Which plants have the smallest sporophytes?
A
Liverworts!
23
Q
What are some characteristics of liverworts?
A
- leafy gametophytes
- smallest sporophytes
- archegonia nd antherida on elevated gametangia
- sporophytes on underside of female gametangia
- no stomata
24
Q
Characteristics of hornworts.
A
- horizontal gametophytes
- long and tapered sporophytes
- no seta, only sporangia
25
What are the most diverse seedless vascular plants? How many species are there?
Ferns! Over 12 000!
26
What are vascular plants characterized by
- vascular tissue (xylem & phloem)
- well developed leaves and roots
- sporophyte dominant
27
What are the characteristics of fern sporophytes?
- rhizoid, underground stem produced by the SAM
- leaves produced by SAM
- roots produced by RAM
28
List out the steps of the fern life cycle. Indicate which structures are diploid and which are haploid.
1. Sporangium (2n) release spores (n).
2. Each spore develops into a bisexual gametophyte (n).
3. A sperm from the antheridia (n) on one gametophyte uses flagella to swim to archegonium (n) on another gametophyte to get to sperm.
4. FERTILIZATION (n) -> (2n)
5. zygote develops into young plant (2n), growing out from archegonium (n).
6. young plant develops into mature plant, with clusters of sori on underside of leaves.
29
What are sori?
Clusters of sporangia on the underside of fern leaves.
30
List some characteristics of fern gametophytes.
- thallus form - not well suited to life on land
- photosynthetic
- rhizoids
- absorbs water and minerals
- antheridia and archegonia on each gametophyte, but self fertilization is rare.
lacks:
roots, stems, leaves, cuticle.
- water required for gamete transfer
31
What are the vascular tissues? What are their functions?
Xylem - transports H2O from roots to wherever
Phloem - transports nutrients from wherever they're produced to wherever they're needed
32
What are the ground tissues?
Collenchyma, parenchyma and sclerenchyma
33
What are the dermal tissues?
Periderm, epidermis, cork
34
What are roots?
Organs that anchor vascular plants and allow for absorption of water and nutrients from soil.
35
What are the 3 types of roots? Briefly describe them.
1. Adventitious - roots rising from stem tissue/rhizome
2. Lateral - a root that branches off another root
3. Primary - first root (and organ) originating from embryo. the o.g. root
36
What are leaves?
Organs increasing surface area of vascular plant, capturing more solar energy to be used for photosynthesis.
37
What are the two types of leaves?
Microphylls and megaphylls.
38
Describe microphyll leaves.
only found in lycophytes, have a single vein.
39
Describe megaphyll leaves.
found monilophytes, gymnosperms and angiosperms.
highly branched vasculature.
40
Describe an advantage of megaphyll leaves over microphyll leaves.
larger, therefore allow for more photosynthetic activity
41
What are sporophylls?
Modified leaves with sporngia
42
Compare and contrast the fern and lycophyte sporophylls.
fern - have sori (clusters of sporangia on underside of sporophyll)
lycophyte - have strobili, cone like structures formed by groups of sporophylls.
43
What are the characteristics of gymnosperms?
Seeds, reduced gametophytes, heterospory, ovules and pollen.
44
What is the main difference between gymnosperms and angiosperms?
Gymnosperm - naked seed, develops in exposed cone
Angiosperm - enclosed seed, develops in capel/fruit
45
Describe the difference between homospory and heterospory
Homospory - production of one type of spore that gives rise to bisexual gametophytes
Heterospory - production of two types of spores that give rise to either male or female gametophytes
46
What are megasporangia? Where are they located?
Located on modified leaves called megasporophylls, produce megaspores that give rise to female gametophytes
47
What are microsporangia? Where are they located?
Located on modified leaves called microsporophylls, produced microspores that give rise to male gametophytes
48
What is an ovule? What is it made of?
A structure that develops within the ovary of a seed plant containing the female gametophyte.
Made up of megasporangium, megaspore and integument(s).
49
How many integuments does an angiosperm ovule have?
2
50
How many integuments does a gymnosperm ovule have?
1
51
What structure of an angiosperm develops into pollen grain?
Microspore
52
What is contained inside a pollen grain?
Male gametophyte
53
Define pollination.
Transfer of pollen to the part of the seed plant containing the ovules.
54
What is the result of the germination of a pollen grain?
Gives rise to a pollen tube which will discharge sperm into the female gametophyte, specifically into ovule.
55
What are some evolutionary advantages of seeds over spores?
- can be dormant for a very long time until conditions are favorable for germination.
- have a stored food supply
- can travel long distances by wind or animals
56
What are cone bearing plants called?
Conifers
57
What ARE cones made of?
Sporophylls which have on them the exposed gymnosperm seeds.
58
What is a seed made up of?
Sporophyte embryo, food supply, and protective coat
59
What are the 3 key features of a gymnosperm lifecycle?
- alteration of generations
- development of seeds from fertilized ovules
- transfer of sperm to ovules by pollen
60
How is pollen captured for gymnosperms?
Captured by ovulate cones
61
How long does it take from cone production to mature seed in gymnosperms?
3 years
62
List out the steps of the pine life cycle. Indicate which structures are diploid and which are haploid.
1. the tree (sporophyte) will have both ovulate and pollen cones. within the ovulate cone are 2 ovules(n)/scale . within each ovule is a megasporangium(2n).
2. in the pollen cone, the microsporocytes (2n) divide by meiosis to become microspores (n) which develop into pollen grains that each contain a male gametophyte within.
3. the pollen grains (n) reach the ovule (2n) , from which it then germinates, producing a pollen tube, allowing for the pollen to make its way through the megasporangium (2n).
4. simultaneously, while the pollen tube develops, the megasporocyte (2n) goes through meiosis to produce four haploid cells, only one of which will survive to become a megaspore(n).
6. megaspore (n) develops into female gametophyte (n) that contains 2-3 archegonia, each of which will form an egg.
7. by the time the eggs are mature, the pollen tubes will have extended to the female gametophyte, containing sperm cells. when their nuclei make contact with the egg's, FERTILIZATION OCCURS (n) -> (2n)
8. only one zygote in archegonium becomes embryo/sporophyte (2n) after fertilization. ovule will then become a seed consisting of embryo/sporophyte (2n), food supply (n), and seed coat (2n).
9. seed then grows into tree wooohooooo
63
How long does it take for fertilization to occur after pollination?
1 year
64
Describe the gymnosperm phylum Cycadophyta.
- thrived during Mesozoic era, however very few species exist today.
- unlike most seed plants, have flagellated sperm
- large cones and palm like leaves
65
Describe the gymnosperm phylum Ginkophyta.
- living fossil!
- only consists of one species, ginko biloba
- also have flagellated sperm
- popular ornamental tree, tho most only plant pollen producing trees bc the female ones stink
66
Describe the gymnosperm phylum Gnetophyta.
- adapted to very extreme environments(tropical or desert)
- 3 genera grouped tgt by molecular data; gnetum (tropical), welwitschia (desert), ephedra (desert).
- not very diverse
67
Describe the gymnosperm phylum Coniferophyta.
- largest gymnosperm phylum
- emerged in jurassic period
- most are evergreens
68
What is the name of the flowering plants?
Angiosperms
69
What are the reproductive parts of an angiosperm?
Flowers and fruits
70
What are the two main groups of angiosperms?
Monocots (1 cotyledon) and eudicots (2 cotyledon)
71
Are there more eudicot or monocot species?
Eudicot
72
Define a flower.
A modified reproductive which contains up to four whorls; sepals, petals, stamens, and carpals.
73
What is the sepal? What is its function?
Green and leafy, enclosing the other parts of the flower.
74
What is the petal? What is its function?
The brightly coloured part of the flower. Attracts pollinators.
75
What is the stamen? What is its function?
A microsporophyll producing microspores that develop into pollen grains containing male gametophytes.
76
Describe the anatomy of the stamen. What is the function of each part?
Consists of:
- a stalk called the filament
- a terminal sac called the anther where pollen is produced
77
What is the carpal? What is its function?
A megasporophyll producing megaspores that give rise to female gametophytes. It is where seeds are enclosed.
78
Describe the anatomy of the carpal. What is the function of each part?
- Ovary, is where the ovules are contained. Where fertilization occurs.
- Style, elevates stigma so that pollinators can reach it better
- Stigma, sticky, where pollen is recieved.
79
What is the difference between complete and incomplete flowers.
Complete - has all four whorls
Incomplete - missing one or more whorls
80
What gives rise to fruits?
The thickening of the ovary wall after fertilization
81
List out the steps of the angiosperm life cycle. Indicate which structures are diploid and which are haploid.
1. megasporangium (2n) undergoes meiosis to produce 4 megaspores, of which, usually only 1 survives and produces a female gametophyte.
2. simultaneously, in the microsporangium (2n), there are many microsporocytes (2n), each of which divides by meiosis producing 4 microspores (n).
3. a microspore develops into a pollen grain(n), in which the generative cell will divide, producing 2 sperm(n). tube cell will produce pollen tube.
4. pollen tube elongates through style(2n) , to reach an ovule(n) and release its 2 sperm.
5. DOUBLE FERTILIZATION , one sperm fertilizes egg cell (n) -> (2n), forming a zygote other sperm fertilizes central cell (2n) -> (3n), forming endosperm.
6. zygote develops into embryo (2n) surrounded by endosperm(3n) and a seed coat (3n). surrounded by fruit as well.
7. when seed germinates, embryo will develop into a mature sporophyte.
82
What are the 7 cells found in an angiosperm female gametophyte?
3 antipodal cells found on one end, egg cell flanked by two synergids on other end, two polar nuclei in central cell.
83
What is the function of the endosperm in an angiosperm seed?
Provides nourishment to developing embryo.
84
What does an angiosperm embryo consist of within the seed?
A root and 1/2 seed leaves depending on if it is a eudicot or monocot.
85
Which 6 crops yield 80% of the calories consumed by humans? Which are monocots and which are eduicots.
Monocots - wheat, rice, maize
Dicots - cassava, potatoes and sweet potatoes
