Plants Flashcards
(82 cards)
1
Q
Heterotroph
A
respirates, but does not fix carbon eg. humans
2
Q
Autotroph
A
self feeders eg. plants
3
Q
Length of time ago plants formed
A
> 3.5 million years ago
4
Q
Stromatolites
A
structures built from cyanobacteria
5
Q
Banded iron
A
formed from free oxygen reacting with free iron in water
6
Q
Consequences of oxygen accumulating in the environment
A
- anaerobic organisms unable to survive
- reacts with methane, creates CO2, cools Earth, causes Huronian Ice age
- ozone created by oxygen rising high in the atmosphere and being hit by UV radiation
oxygen-breathing organisms are able to form
7
Q
Chloroplasts
A
type of plastid containing chlorophyll, where photosynthesis takes place
8
Q
Endosymbiosis
A
cyanobacteria engulfed by amoeba-like eukaryote, kept alive, plastids transferred to host
9
Q
Evidence of endosymbiosis
A
- plastids have double membrane
- plastids have own DNA
- plastid DNA is ring structure, not chromosomes
plastids have similar structures to cyanobacteria (thylakoids = membrane structures containing chlorophyll) - plastid DNA related to cyanobacteria DNA
10
Q
Why genes are lost
A
- not needed
- transferred to host nucleus
- redundancy as host has same gene
11
Q
Photosynthetic eukaryote originating from different event
A
Paulinella chromatophora
12
Q
Accessory pigments
A
absorb different wavelength of light to chlorophyll, so provide energy to algae in deep water
13
Q
Kleptoplast
A
stolen plastid through secondary endosymbiosis
14
Q
Mixotroph
A
feed through both predation and photosynthesis eg. Euglena
15
Q
Secondary endosymbiosis
A
photosynthetic eukaryote with primary plastids is engulfed
16
Q
Evidence of secondary endosymbiosis
A
- plastids have 4 membranes
- in some cases original nucleus of eukaryote is still present reduced form of nucleomorph
- relationships based on plastid DNA show brown seaweed is directly related to red algae
17
Q
Lost photosynthesis
A
Once gained, photosynthesis can be lost eg. common in Alveolata
18
Q
Tertiary endosymbiosis
A
occurs in lineages where photosynthesis was lost eg. Dinoflagellates
19
Q
Dinoflagellates
A
responsible for algal blooms
20
Q
Emiliana huxleyana
A
Haptophyte, ocean organism that produces blooms
21
Q
Effect of E.hux on climate
A
- increases reflectivity of ocean
- promotes cloud formation my excreting dimethyl sulfoxide
- body made from calcium carbonate, create geological formation
22
Q
Diatom
A
photosynthetic organism with silica shell
23
Q
Plasmodium
A
malaria causing parasite, recent photosynthetic ancestor, plastids contain genes for survival due to transfer
24
Q
Green algae
A
green photosynthetic organisms, daughter cells stay attached through binary fission
25
Colonial lifestyle
- filamentous or spherical
- all cells are equal
- not usually attached to substrate
- cells can survive alone as metabolically independent
- all cells can have sex
prone to being swept away
26
Multicellular lifestyle
- cells are not all equal
- cells are specialised
- not all cells are metabolically independent
- usually attached to substrate
reinforced bottom structure, cannot be swept away
- simultaneous occupation of multiple environments
- not all calls can have sex
27
Problems of plants moving to land
- Hydration
- Support
- Water for metabolism
- Nutrient uptake
- Temperature variation
- Damaging light levels
- High oxygen concentration
- Sex cell dispersal
- Dessication of gametes
28
Advantages of plants moving to land
- No filter on useful light
- High O2 concentration
- Escape competition
- Escape predation
29
Lichen
producers, association of fungi with single cell algae
- fungus provides structure and inorganic nutrients
- Algae photosynthesises
30
Haplo-diplont
all land plants, have a sporophyte and gametophyte generation
31
Early land plants
- spores covered in sporopollenin
- gametes produced in gametangia
- eggs retained on mother plant
- zygote retained and supported by mother plant
- sporophytes dependent on mother
- spores produced in sporangium and released
32
Apical meristem
responsible for building plant as it grows
33
Liverwort
- earliest group of land plants
- can be leafy - one cell thick
- can be thalloid - flattened branched stem
34
Bryophyte
- hornworts, liverworts and mosses
| - sporophyte is constantly dependent on gametophyte
35
Mosses
`- very diverse, found in most places apart from deserts
36
Sphagnum
Bog moss, ecologically important, occupies and creates peat bogs, makes environment mor acidic and allows peat to form from carbon
37
Polytrichum
- moss which evolved splash cups for easy fertilisation
| - some cups are coloured to attract insect pollinators
38
Dwarf males
mosses develop ability for male spores to germinate when they land on female
39
Hornworts
- Anthocerophyta
- look like liverworts
- have stomata
- sphorophytes are long lived and remain dependant on gametophyte
40
Vascular Plants
- freely dispersed spores germinate to gametophyte
- sporophyte forms and grows nigger and forms roots and branches
- sporophyte becomes independent and mother gametophyte dies
41
Terminal sporangia
- spore bodies at end of stem
| - seed plants, monilophyta
42
Lateral sporangia
- spore bodies along edge of stem
| - lycophyta
43
Monilophyta
- include ferns
- leaves are megaphyll, evolved through webbing
- evolved from terminal sporangia, spores moved underneth through selection to keep dry
44
Lycophytes
- inclides microphyll leaves, evolved from scales
- evolved fro lateral sporangia and leaves are simple and triangular
- includes Selaginella
45
Homosporous
- only one type of spore, bisexual
- no sexual dimorphism
- single type of gametophyte
46
Heterosporous
- two types of spore, sperm or egg
- allows sexual dimorphism
- unisexual gametophyte
47
Progymnosperms
- spores remained on mother plant due to dry conditions and grow into gametophyte
- gametophytes are dispersed instead of spores
- male gametophyte lands on female still attached to mother plant
48
Progymnosperm male gametophyte
- reduced in size
- loss of independence, no chlorophyll
- sculpted for air resistance
- becomes pollen
49
Progymnosperm female gametophyte
- reduced in size and complexity
- totally dependent on the mother
- becomes enclosed by mother
- becomes ovule
50
Archaegonium
specialised organ that produces egg cell, exists in early seed plant
51
Why seeds are beneficial
- headstart in growth
- are supported
- food supply
- protection against animals and dessication
52
Seed plant
- spores are made through meiosis and retained and supported
- male gametophytes are dispersed and land on femle
- sporophyte grows and seeds are dispersed
- favoured by dry environments
53
5 lineages of seed plants
Cycadophyta - large, spiky, poisonous (swimming sperm)
Ginkophyta - only one living species, Ginko boloba (swimming sperm)
Coniferophyta - some are deciduous, some are evergreen (pollen tube)
Gnetophyte - Gnetum, Ephedra, Welwitschia (pollen tube)
Anthophyta - Angiosperms
54
Ancestral Angiosperms
- low density
- used insects or other pollinators
- ovule becomes enclosed
- gametophyte reduces to 7 cells and becomes more adaptable
- pollen sticks out to touch insects
- coloured petals attract insects
- have endosperm
55
Endosperm
- specialised food tissue from double fertilisation
- pollen has 2 nuclei
- Tube cell works then dies
- Generative nucleus divides into 2
56
Vascular tissue
Xylem - takes up water
| Phloem - takes sugars from leaves to roots, have companion cells with nucleus to improve transport control
57
Monocot
- one seed leaf
- always monoaparture (one hole)
- 20% of world population
- reffered to as bulbs
- contains bluebells, daffodils, grasses
- became aqutic, became herbaceous, returned to land
58
Dicot
- two seed leaves
| - either monoaparture or triaparture
59
Apartures
holes in angiosperm pollen in which water enters, allowing pollen to germinate
60
Archaedicot
- primitive, monoaparture dicots
- 3% of world population
- includes magnolias and water lilies
- usually tropical
- monocots and eudicots evolved independently from these
61
Eudicot
- advanced, triaparture dicots
- 77% of world population
almost any European tree, apart from conifers
62
Amborella
- first split between living flowering plants
- happened 175 million years ago
- one living species in Caledonia
63
Second branching flowering plants
- water lilies
- first known aquatic seed plants
- lots of petals
- first herbaceous seed plants
64
Third branching flowering plants
contains 3 rare families
65
Fourth branching flowering plants
- splits into 5 lineages
- Magnolia group
- Monocots
- Eudicots
- 2 other small groups
66
Magnolia group
- contains magnolia and 97% of archaedicots
- first herbaceous and non-aquatic seed plant
- archaedicots have unique oil cells
67
Aristolochia
- has specialised pollination: pollination by deception
- fly is attracted to smell of rotting meat, crawls inside, trapped due to downward pointing hairs, pollen scatters over fly body, fly escapes, pollinates other flower
68
Evidence for monocots becoming herbaceous
- at base of family tree they arose from archaedicots
| - many basal monocots are aquatic
69
Monocot defining characters
- no secondary growth, which fattens tree trunk (only one is tree = palm tree)
- have herbaceous ancestor
- have vascular bundles of complex structure, give wek support, improved flexibility for aquatic ancestor
- absence of primary root (aquatic angiosperms are free floating)
- loss of cotyledon
- leaf ventilation and shape (linear leaf shape appears in aquatic plants)
70
Eudicot flower specialisation
- earliest flowers had petals in spiral arrangement
- lineages evolved to have whorl arrangement
- whorl arrangements can evolve to bilateral symmetry, fused carpals, or fused petals
71
Compound flowers
- small flowers group together in the middle, and open at different times to receive different pollen to increase genetic diversity
- large flowers to attract attention
72
Seed dispersal by animals
- hooks: attach to animal externally
- internal food - eaten and excreted
- external food - taken and stored away
73
Abiotic seed dispersal
- wind
- physical eg. catapult
- water
74
Ethnobotany
indigenous uses of plants give clues to undiscovered drugs
75
Parasitic orchids
- all orchids start off being parasitic on fungi
- seeds germinate if parasitic fungus attempts to attack
- some become entirely photosynthetic, others remain partly parasitic to grow in shade
76
Parasitic toothwort
- are parasites on trees
- lost ability to make chlorophyll
- steals energy from tree
77
Parasitic striga
- attacks African maize crops
| - seed senses root, germinates and seeks root, atttaches, starts parasitism, aerial parts develop
78
Solution to striga parasite
- legume Desmodium is planted
- more attractive to striga
- striga senses desmodium root, germinates and seeks root, can't attach, starves and dies
79
Carnivorous plants
- either use sticky leaves, or pitfall trap structure
- do not eat insects for energy as they photosynthesise
- eat insects for extra nutrients
80
Strangling figs
- land and germinate on tree branch, grow doen and develop thickly over trunk, strangle snd kill tree, take its place
81
Arum
- compound flower (monocot), uses pollination by deception
- smell of rotting meat, attract insects
- beneficial for plants that occur at low frequencies
82
Ophrys
- "bee orchid" - flowers mimic female insect
- male insects attempt to mate with flower, pollen gets attached, fertilisation occurred when insect attempts to mate with other flower
