theme 2 Flashcards
(132 cards)
1
Q
what does multicellularity lead to?
A
specialized cells giving rise to tissues/organs with specialized functions
2
Q
what is an organisms phenotype dependent on?
A
cell number, type and function
3
Q
what is the result of multicellularity?
A
tissue specific activation of genes
4
Q
are plants sessile or immobile?
A
sessile, just slow
5
Q
why do we classify things?
A
to understand similarity and diversity of living organisms in an organized manner
6
Q
how can organisms be grouped together?
A
based on common characteristics: morphological and sequence homologies
7
Q
what does classification provide information on?
A
evolutionary lineages
8
Q
what are the 7 defining characteristics of land plants?
A
1.eukaryotes
2.photoautotrophs
3.multicellular
4.sessile or stationary
5.cell walls
6.alternation of generations life cycle
7.embryo retained on the gametophyte tissue
9
Q
what features do plant cells share?
A
1.primary cell wall
2. cytoplasm and organelles
3. cellulose fibres
4. rigid but flexible
10
Q
where are cellulose fibres found?
A
matrix of hemicellulose
11
Q
top to bottom, what is the plant cell wall structure?
A
cellulose, structural protein, hemicellulose, pectin
12
Q
what are cellulose fibers anchored with?
A
lignin
13
Q
what do secondary cell walls do?
A
- stronger and more rigid
- creates waterproof barrier
14
Q
does the cell wall provide rigidity?
A
no
15
Q
how does the cell create rigidity?
A
the turgor pressure from the vacuole pushing against the cell wall
16
Q
how are plant life cycles different from animals?
A
-one free living diploid individual
-gametes are formed through meiosis
-gametes are not free living
17
Q
land plants are classified based on the presence of?
A
- vasculature
- seeds
18
Q
what do vascular bundles consist of?
A
xylem, phloem, parenchyma cells, fiber cells
19
Q
what type of cells are fiber cells?
A
sclerenchyma cells
20
Q
what do fiber cells do?
A
provide rigid support to the xylem and phloem
21
Q
what are xylem?
A
water conducting cells
22
Q
what are phloem?
A
cells that transport sugars and other solutes
23
Q
how are water conducting cells strengthened?
A
by lignin
24
Q
what is the most abundant polymer?
A
cellulose
25
what is the second most abundant polymer?
lignin
26
what are traits of lignin?
hydrophobic and aromatic in nature, resistant to degradation by chemicals
27
how does lignin provide rigidity and strengthen the cell wall?
it is co-valently linked with cell wall polysaccharides
28
what are the three main groups of classification of land plants?
nonvascular plants
vascular seedless plants
vascular seed plants
29
what are nonvascular plants?
bryophytes
30
what are traits of nonvascular plants?
lack vascular tissue
haploid generation is dominant
31
what are vascular seedless plants?
lycophytes and pterophytes
32
what are traits of vascular seedless plants?
have well developped vascular tissues but do not make seeds
diploid generation is dominant
33
what are vascular seed plants?
gymnopsperm and angiosperms
34
what are straits of vascular seed plants?
have well developped vascular tissues and produce seeds
35
what type of plant was the first to appear on land?
bryophytes
36
what do bryophytes lack?
conducting tissues
37
where do bryophytes grow?
close to the ground on wet sites, plants are small
38
what does poikilohydric mean?
variable water
39
what are implications of bryophytes being poikiliohydric?
-have little control over internal water content
-do not restrict water loss
-when habitat dries out, they also dry out
-they are drought tolerators not avoiders
40
what does it mean when something has little control over internal water content?
they cant maintain or regulate their internal water content
41
what do gametangia produce?
gametes in shelter
42
what do archegonia produce?
eggs
43
what do antheridia produce?
sperm
44
what are rhizoids?
root like structures that help in anchoring
45
what do filamentous protonema do?
spores germinate and produce protonema
46
what is the dominant phase of the bryophyte life cycle?
gametophyte (gamete amplification)
47
why is water required to run the life cycle?
because flagellated sperm need water to swim to the egg
48
where is the sporophyte reatined in bryophytes?
in the gametophyte
49
what are microphylls?
narrow leaves with one strand of vein or vasculature
50
what do microphylls represent?
modification of stems
51
where are microphylls found?
only in lycophytes
52
what are megaphylls?
broader leaf with multiple veins
53
where are megaphylls found?
all other vascular plant
54
what are advantages of megaphyll?
large surface area, more photosynthesis
55
what is the most abundant group of seedless vascular plants?
ferns
56
where do ferns grow?
in habitats from wet to arid conditions, dont need continuous moisture
57
what are traits of ferns?
-large sporophyte
-vasculature
-roots
-megaphyll
58
what is the dominant phase of seedless vascular plants?
sporophytes
59
what do sporophytes in ferns produce?
plant body with leaves and roots
60
why do pterophytes need water for their life cycle?
the flagellated sperm need water to swim to egg
61
what are the two groups of seed plants?
gymnosperms and flowering plants
62
what type of seeds do gymnosperms have?
naked seeds
63
what type of seeds do flowering plants have?
seeds are covered
64
what is the dominant phase of gymnosperms/angiosperms?
very large sporophytes
65
what do gymnosperm pollen grains produce?
non-motile sperm
66
what is pollination?
transfer of multicelle haploid pollen to female reproductive parts
67
what is the ovule?
a sporophyte structure that produces female gametophyte with egg
68
how is the ovule connected to the sporophyte?
by protective tissue
69
why are male structures lower than the female counterparts?
to avoid self pollination
70
what do reproductive structures contain?
haploid spores
71
which gametophytes is released?
pollen
72
what are female cones?
megaspore
73
what do megaspores produce?
female gametophyte inside the ovule
74
what are male cones called?
microspores
75
what do microspres produce?
male gametophyte (pollen)
76
what does the ovule become once the egg is fertilized?
the seed
77
how many megaspores survive after meiosis?
one
78
what do embryos compete for?
food and space
79
how many embryos come from one fertilization?
4 embryos
80
what produces male gametophyte?
microspores
81
what houese the female gametophyte?
the ovule
82
what produces the female gametophyte?
megaspore
83
what is the system of major gymnosperm reproductive adaptations?
inside the ovule--> megasporangia--> megaspore produces female gametophyte--> archegonia--> egg cells
84
how is the female gametophyte physically connected to the sporophyte?
many layers of tissue
85
what state is pollen in when finding the egg cell?
an quiescent and dry state
86
what happens once the pollen is hydrated?
it produces the pollen tube
87
what does the pollen tube do?
grows through the egg to deliver the sperm cell
88
what is the embryo encased in?
a seed
89
why does the gymnosperm need to be encased in a seed?
to protect it so it can be transported away from the parent
90
what are traits of conifers?
-cone beareres
-most common gymnosperms
-pines, spruces, firs
-woody reproductive cones
91
what is the phylum coniferophyta?
conifers
most are evergreen
92
what are traits of evergreens?
-shed some but not all leaves
-needle leaves
-produce resin
-used for timber and paper
93
what is the largest group of land plants?
angiosperms
94
what adaptations do angiosperms have?
-double fertilization
-overy protects ovule
-efficient transport of water and nutrients
95
what does a double fertilization in an angiosperm produce?
embryo and endosperm
96
how is transport of water and nutrients more efficient in angiosperms?
-they have vessel elements
-more efficient phloem
97
what type of seed do angiosperms have?
covered seeds
98
what type of plant are angiosperms?
flowering plants
99
what do flowers contain?
carpels at their center
100
what does the fruit of the plant do?
nourishes and disperses seeds
101
what do the ovaries in angiosperms do?
protect ovules and seeds
102
what is a monocot?
single cotyledon
103
what is a eudicot?
2 cotyledons
104
what type of seeds do monocots have?
single seeds
105
what type of seeds do eudicots have?
double (two halves in one seed)
106
what type of leaves do monocots have?
leaf veins form a parallel pattern
107
what type of leaves do eudicots have?
leaf viens form a net pattern
108
what type of flower do monocots have?
flower parts in threes and multiples of threes
109
what type of flower does eudicots have?
flower parts in fours or fives anf their multiples
110
how many sporangia are in each anther?
2-4
111
what does fusion with sperm cells create?
diploid zygote and the first triploid endosperm cell
112
what do fertilized ovules develope into in a flowering plant?
seeds
113
what do the ovaries develop into for a flowering plant?
fruit
114
what happens when the pollen is mature in a flowering plant?
anthers rupture, allowing the pollen to be dispersed
115
what has to happen before fertilization can occur in flowering plants?
pollen must germinate and grow through the style
116
what does each carpel of a flowering plant produce?
one or more ovules
117
what does the female ga,etophyte in a flowering plant consist of?
eight nuclei and seven cells
118
how many mitotic divisions occur in flowering plants?
3
119
what does the triploid endosperm give rise to?
an endosperm
120
what colour of wave length does chlorophyll need to be excited?
red
121
what does red light do to seeds?
triggers germination
122
what is coevolution?
two or more species interact closely in the same ecological setting
123
what does co-evolution result in?
heritable change in one affects the other
-plants have evolved to attract pollinators
-animals have evolved various behaviours and body parts for pollination
124
how many estimated species are there?
8.7 million species
125
what is the largest identifies group?
plants
126
what is the largest unidentified species?
marine species
127
why do the tropics have more biodiversity?
-high precipitation
-high temperatures
-high energy
128
why does the arctic have low biodiversity?
-short season
-little energy
-low precipitation
-cold temps
129
what common anatomy and physiology do plants and animals share to live on land?
-mechanisms to avoid desiccation tolerance
-drought tolerators vs avoiders
-presence of dry skin/cuticles in animals
130
what pushed diversity on land?
selection pressure
131
what did plants and animals evolve from?
terrestrial ancestors that were adapted with either vasculature or bones
132
