Plants Flashcards
what is a prochloron
unicellular oxygenic photosynthetic prokaryote
where are prochlorons found
as an extracellular symbiont on coral reefs
what is a chlorophyte
green algae
what are the ancestors of land plants
chlorophyta
where are chlorophyta found
fresh water and marine waters
what do chlorophyta have
filaments and fronds
what are the ancestors of true plants
charophytes
where are charophytes found
shallow waters
how are charophytes adapted to shallow waters
can survive drying out
ideal pressure for evolving into land plants
what is a Coleochaete orbicularis
charophyte
what is a Chara
charophyte
how have plants adapted to life on earth
strength eg tree trunk big eg grow tall resist water loos eg guard cells resist herbivores eg thorns make msot of terrestrial vectors eg pollination
what are the uses of plants vacuoles
store excess salts to prevent shrivelling
maintain rigidity inside cell
what is the main conducting element in pteridophytes & gymnosperms
tracheids
what is the main conducting element in angiosperms
vessels
what type of skeleton does a vacuole have
hydrostatic
what alters the chemical properties of chloroplasts
Small changes in the structure of chlorophyll alter the wavelength of light absorbed
which way do the grana of chloroplasts move
toward the direction of light
what are the three photosynthetic pigments
carotenoids
chlorophyll a
chlorophyll b
what colours do chlorophyll a absorb
red and violet
what colours do chlorophyll a reflect
green
what colours do chlorophyll b absorb
blue
what colours do chlorophyll b reflect
violet
yellow
red
what colours do carotenoids absorb
blue and green
what colours do carotenoids reflect
yellow and red
what are plant walls strengthened with
lignin
what are plant cell walls made of
cellulose - polysaccharide
what form of carbon fixation forms 3 phoshpglycerate
C3
what does C3 carbon fixation form
3 phosphoglycerate
when did C3 carbon fixation evolve
3 billion years ago
under what circumstances did C3 carbon fixation evolve
high CO2 low O2
when does C4 carbon fixation occur
prefaces calvin cycle
what does c4 carbon fixation produce
malate - 4c product
where is malate produced
in mesophyll cells during c4 carbon fixation
where is the co2 from c4 carbon fixation stored
in bundles of sheath cells
what is the gametophyte dominant in
bryophytes
what evolutionary innovations enabled seed plants to outcompete ferns and other seedless plants that dominated through the end of the carboniferous period
reduced, dependant gametophytes
what feature distinguishes angiosperms from gymnosperms
angiosperms are held within an ovary
why is CO2 and malate stored in mesophyll cells
these are used in the calvin cycle which occur in mesophyll cells
how does initial c-fixation occur
via RuBisCo - adds co2 to ribulose biphosphate
what happens to c3 plants on hot. dry days
stomata partially close so less sugar produced and decreased levels of co2 in leaves which starve the calvin cycle
what happens in the calvin cycle if CO2 is scarce
RuBisCo adds o2 to ribulose biphosphate instead of co2. A 2C compound is formed which leaves the cholorplasts
what happens in photorespiration
CO2 is released
the releasing of CO2 does what to ATP
is consumed not made
agricultural uses of c3 plants
rice
wheat
soybeans
agricultural uses of c4 plants
sugarcane & corn, species in Poaceae
c4 plants evolved as a result of plants adapting to what
high light intensities
high temperatures
dryness
how do c4 plants eliminate photorespiration
concentrating co2 in bundle sheath cells
where do c4 plants dominate
grassland floras & biomass production in the warmer climates of the tropical & subtropical regions
what does CAM stand for
Crassulacean Acid Metabolism
where do mesophyll cells store oxaloacetate
in the vacuole until morning
when does the calvin cycle occur in CAM plants
in the day when stomata are closed
what are the two life cycles of plants
gametophyte
sporophyte
how are gametophytes formed
haploid spores germinate producing a gametophyte via mitosis
how are sporophytes formed
gametes fuse together in the archegonia forming a zygote which grows via mitosis to form a sporophyte
how/where do gametophytes form gametes
in gametangia via osmosis
where are male gametophyte gametes produced
antheridia
where are female gamtophyte gametes produced
archegonia
what happens in the sporangia
sporophytes produce 1n spores by meisosis
down side to Gametophytes
sensitive to stress
dependant on moisture
advantages of Gametophyte
encourages outbreeding - maximises chances of new combination of genes
(1 set of same chromosomes causes vulnerability)
what are embryophytes
true plants
what are the charactristics of true plants
mutlicellular dependant embryos
apical meristems
walled spores produced in sporangia
what are apical meristems
Localised regions of cell division producing longitudinal growth in plant organs
how many phyla in extant land plants
10
how many phyla of Bryophytes
3
how many phyla of Pteridophytes
2
how many phyla of Gymnosperms
4
how many phyla of Angiosperms
1
the evolution of embryos in plants formed
Bryophytes
the evolution of flowers in plants formed
angiosperms
the evolution of a vascular system in plants formed
Pteridophytes
the evolution of seeds in plants formed
gymnosperms
nonvascular plants are
Bryophytes
vascular seedless plants are
lycophytes
pteridophytes
vascular seeded plants are
angiosperms
gymnosperms
spermatophyta
out of c3, c4 and cam plants, which would stand to gain more from increasing co2 levels
C3
when is chlorophyll b used
in autumn
what evolved in plants 432-476 million years ago
embryos evolved
what first appeared in fossil records 432-476 millions years ago
spore tetrads
cuticles
what does the forming of embryos and spore tetrads represent
extinct lineages between charophytes and liverworts
what happened to plants 402-432 million years ago
decline in spore tetra diversity
rise in dominance of individually dispersed simple spores
what happened to plants 256-398 million years ago
diversity of spores and megafossils increased
increase in vascular plant diversity
what is sporopollenin
decay resistant spore cell walls
why were land plants small 402-432 million years ago
no lignen structure
why did plants grow tall
competition for sunlight
what are the important trends in plants evolution
Less dependence on water
Increase in size, especially height
Increased exploitation of vectors for dispersal
Changes in life cycle - Increasing dominance of less vulnerable stages
what plants are in the bryophytes group
liverworts
hornworts
mosses
The first true plants (Embryophytes) to evolve
Bryophytes
byrophytes have three separate evolutionary lines meaning they are
not monophyletic
which bryophyte is most closely related to vascular plants
mosses
where is the stomata on moss
on the sporophyte
characteristics of bryophytes
small thrives in moist conditions can survive dry periods sporophyte grows/dependant on gametophyte gametophyte is dominant stage no true roots, stem or leaves needs water for fertilisation
how do bryophytes use water for fertilisation
sperm swims in water to find egg
what are the three living phyla of byrophytes
hepatophyta
bryophyta
anthocerophyta
what are the two types of liverwort
thalloid liverwort
leafy liverwort
characteristics of thalloid liverwort
no leaf life structures
flat thallus
rhizoids on lower surface
what are rhizoids
collection of cells which form a filament
characteristics of leafy liverwort
no true stem or leaves but leaf/stem like structures
why cant liverworts adapt to changes in the environment
no stomata
how does the gametophyte of a moss start
protonema
what are the two types of moss
arcocarpous and pleurocarpous
characteristics of arcocarpous moss
archegonia and capsules borne at tips of stems and branches
once fruited, branches take over erect growth
what are the characteristics of pleurocarpous
archegonia and capsuls borne on short lateral branches - not tips of branches
form carpets not erect growth
what is the defining component of peat bogs
Sphagnopsida (Sphagnums)
why are peat bogs important
cover 3% of worlds area contain 30% of all global soil carbon fuel occur in over 180 countries represent 1/3 of global wetland resource
what is the most common type of byrophyte
byropsida
what is a Anthoceros
hornwort
what classes make up the phyla pterophyta
sphenopsida
filicopsida
psilotopsida
what are the first true vascular plants
pteridophytes
what do tracheids enable
transport of water and mineral salts
what are the common characteristics of pteridophytes
sporophyte dominant
true roots, shoot and leaves
true vascular system
what does the xlyem in pteridophytes do
transports water and minerals from soil to shoot
provides woody skeleten - bigger and stronger
what does the phloem in pteridophytes do
conducts photosynthate from leaves to rest of plant
why do pteridophytes prefer shady moist conditions
needed for reproduction - sperm swim in water to egg
why is the pteridophytes exploitation of drier areas limited
water needed for reproduction
what phyla make up the pteridophytes
Lycopodiophyta
Pterophyta
what is a Psilotopsida
whisk fern
what is a Sphenopsida
horsetail plant
what is a Filicopsida
fern
what are the oldest extant plants
lycopodiophyta
characteristics of lycophyta
stems on horizontal rhizomes
small microphyllous leaves - supported by a single strand of vascular tissue
sporophyte dominant
where are sporangia found on lycophyta
sporophylls grouped into stoboli
what is a Selaginella
lycophyta
what is a Lycopodium
lycophyta
what are the families of Psilotopsida
Psilotaceae and Ophioglossaceae
what is a Psilotum
Psilotopsida
what is a Tmesipteris
Psilotopsida
how do Sphenopsida survive in marshy environments
have hollow stems which conduct air to roots growing in anaerobic environment
what is a Equisetum arvense
horsetail
what is a Equisetum telamatia
horsetail
what is the largest group of pterophyta
ferns - filicopsida
what is Circinate vernation
the manner in which a fern frond emerges
why do fern fronds curl
As the fern frond is formed, it is tightly curled so that the tender growing tip of the frond (and each subdivision of the frond) is protected within a coil.
where are sporangia on ferns
under leaves
leaf msrgins
special branches
what do some sporangia of ferns do with spores
catapult spores away from leaves into airstream
what is a Azolla
water fern
what is a Marsilea
water fern
what is a Salvinia
water fern
what is a Osmunda
fern
what is a Ophioglossum
fern
do angiosperms have naked or enclosed seeds
enclosed
do gymnosperms have naked or enclosed seeds
naked
what are angiosperms enclosed in
ovary
how many living plants are angiosperms
90%
Why did the gymnosperms begin to outcompete seedless vascular plants?
their stomata closed preventing water loss
describe the vascular system of spermatophyta
phloem has companion cells and sieve tubes
secondary xylem - wood for trees
how do spermatophyta reproduce
pollen carried to stigma then get carried by wind or animals
advantages of reproducing by seeds
full exploitation of terrestrial areas
what protects the gametophyte of spermatophytes
sporophyte
where is the male gametophyte in spermatophytes
integrated into pollen grain - microspore
where is the female gametophyte in spermatophytes
integretaed into ovule - megaspore
describe the seed structure of gymnosperms
on layer of integument - no protection
describe the seed structure of angiosperms
two layers of integuments inside an ovary - protection
5 traits of seed plants
ovules seeds pollen heterospory reduced gametophytes
advantages of seeds over spores
survive better than unprotected spores
can be transported long distances
advantages of seed plants using pollen
dont need water for reproduction
can survive away from water
what is a cycad
gymnosperm
what is a gingko
gymnosperm
what is a conifer
gymnosperm
gnetophyta
gymnosperm
gymnosperms have no true flowers so have no
petals
where are microsporophylls arranged
in male cones in gymnosperms
where are megasporophylls arranged
in female cones in gymnosperms
where are seeds borne in gymnsperms
megasporophylls
what shurbs and trees
gymnosperms
how are gymnosperms often pollinated
by wind
what is a Ginkgo biloba
Gingkophyta - gymnosperm
what is the only species of Gingkophyta
ginkgo biloba
cycadophyta plants are dioecious - what does this mean
plant is either all male or all female
how many genera of gnetophyta
3
what is a Welwitschia
gnetophyta - gymnosperm
what is a Gnetum
gnetophyta - gymnosperm
what is a Ephedra
gnetophyta - gymnosperm
how are the sporophylls in Welwitschia mirabilis organised
male and female strobili
what is a Welwitschia mirabilis
gnetophyta
characteristics of gnetum
broad leaves
woody stems
seeds not borne in cones
what is the gnetum the genus of
tropical vines and trees
characteristics of conifers
needle like leaves
thick cuticles
is a conifer a xerophyte
yes
what conditions are conifers adapted to
frozen soil
hot and dry
what is the oldest living organism
Pinus longaeva - conifer
tallest living organism
Sequoiadendron gigantum - conifer
what is a bitegmic ovule
angiosperm
what is an endosperm
angiosperm
what is a carpel
angiosperm
what is the closest living relative to angiosperms
gnetophyta
what is the name of the only phyla of angiosperms
anthophyta
what two groups are angiosperms split into
Dicotyledons
Monocotyledons
describe the embryo of monocots
one cotyledon
describe the veins of monocots
parallel
describe the vascular bundle arrangement in monocots
complex
describe the roots in monocots
fibrous
describe the floral parts o monocots
mutliples of three
describe the embryo of dicots
two cotyledon
describe the veins of monocots
netlike
describe the vascular bundle arrangement in dicots
ring
describe the roots in dicots
taproot
describe the floral parts in dicots
multiples of four or five
1/3 of angiosperms are
monocots
2/3 of angiosperms are
dicotsw
describe double fertilisation in angiosperms
Two sperm cells are discharged into the female gametophyte
1 sperm fertilizes the egg (forms diploid zygote)
1 sperm fuses with 2 nuclei in large central cell of the female gametophyte (forms a triploid cell, i.e. the endosperm)
what is the triploid cell in angiosperms
endosperm
characteristics of angiosperms
colourful petals
why do angiosperms have colourful petals
signal to vectors for pollination
structure of flowers
sepals
petals
stamens
carpels
role fo stamens
produce pollen
role of carpels
produce ovules
what do ovaries ripen in to
fruits
advatnages of animal vectors over wind
animals more likely to go to female flowers whereas wind is random - reduces pollon waste
not weather dependant
exploits greater ecological niches
how does the corpse flower pass on its pollen
emits smell which attarcts insects insects enter flowee rises and traps them projection emits heat 3 days later it delfates releasing insects containing its pollen
how many petals do cruciferae have
4
what is a cruciferae
angiosperm family
what is a leguminosae
angiosperm family
what is A Compositae
angiosperm family
what is the largest plant family
Compositae
what is a Orchidaceae
angiosperm family
what is a Graminae
angiosperm family
what crops make up the Graminae family
wheat
barley
maize
rice
what are parenchyma cells packed with
chloroplasts
how do butterworts feed
sticky stuff on leaves smell nice attracting insects
insects get stuck to leaf
plant ingests insect juice
why do the hairs on Venus fly traps need to be triggered twice
stops them wasting energy opening and closing for no reason
how do leaves minimise self shading
by arranging themselves in foliar mosaics
why is nitrogen hard for plants to obtain
quired in large amounts No mineral source Just liberated from decaying organic material Very soluble Easily lost by leaching from sandy soils Denitrification Loss from nitrate as nitrogen gas A feature of anaerobic soils (e.g. bogs)
how do root nodules help plants get nitrogen
nodules contain rhizobia which fix nitrogen, giving some to the plant
what do rhizobia get from their symbiosis
sugars from plant
what type of plant host rhizobia
legumes
how do carnivorous plants gain nitrogen
eating insects
where are carnivorous plants found
bogs
how do bladderworts catch prey
suck them in
how do Hemiparasites obtain organic compounds
photsynthesis and via haustoria attached to hosts roots
what are Orobanche
angiosperm parasites
what are Striga
angiosperm parasites
what is a Rafflesia
angiosperm parasite
how do Coralroot orchid get energy
Gets energy and nutrients via fungi that live in a lumpy mass at the base of its stem
some chloroplasts in stem so slight photosynthesis
how does Bird’s-nest orchid get energy
growing on the roots of trees