Plants and their cell components Flashcards
(74 cards)
1
Q
Evolution
A
Is a change in the heritable characteristics of a population over generations, or the process of diversification by which new species or populations develop from pre-existing forms
2
Q
Darwin
A
“descent with modification”
* Species are descended from a common ancestor
* Species change over time
3
Q
Population Genetics
A
A change in population allele frequencies over time
* “modification” is the result of genetic changes
4
Q
Phylogeny
A
A hypothesis of ancestor-descendent relationships
5
Q
Nodes
A
Represent common ancestors
6
Q
Tips
A
Represent the descendants of that ancestor
7
Q
Roots
A
As we move from root to tip we are moving forward in time
Anchor the plant and collect water
8
Q
Vascular Tissues
A
They transport water and nutrients upward from the soil to leaves, where photosynthesis takes place
9
Q
Vascular plants
A
Plants with plumbing
10
Q
Synapomorphy
A
- Shared derived trait
A characteristic present in an ancestral species and shared exclusively (in more or less modified form) by its evolutionary descendants
11
Q
Synapomorphy in plants
A
Tracheids
Vascular tissue
Xylem
Phloem
12
Q
Tracheids
A
Elongated cells that transport water and mineral salts through the Xylem of vascular plants
13
Q
Xylem
A
Transports water through the plant
14
Q
Phloem
A
- Living vascular tissue that carries sugar and organic substances throughout a plant
- Organic compounds (made from photosynthesis)
15
Q
When were xylem first present in fossil records
A
mid-silurian
16
Q
The first seed trees
A
- Mature trees with good genetic characteristics and high seed production
- Evolved for the first time at the end of the Devonian period.
- The earliest member of the lignophyte clade
17
Q
Progymnosperms
A
- Extinct seedless vascular plants that may be ancestral to seed plants
18
Q
Lignophytes
A
Woody plants
19
Q
Ethnobiology
A
The study of how traditional cultures classify objects and organisms in the natural world
20
Q
Cereal grain
A
Fruits of grasses (monocots) that can be gathered or cultivated as a food for humans
Human civilization was founded on cereal grains
21
Q
What are plants?
A
Plants produce oxygen while packaging the sun’s energy into compounds needed for life. They make up more than 80% of the total biomass on earth
22
Q
Bacterial cell walls
A
Composed of peptidoglycan, a complex of protein and sugar
23
Q
Archaeal cell walls
A
Composed of polysaccharides (sugars)
24
Q
Eukaryotic cell walls
A
Found in plants are composed of cellulose, and the cell walls of fungi are composed of chitin
25
Archaeplastida super-groups
Consists of three major groups:
- Viridiplantae (green algae and plants)
- Red algae (Rhodophyta)
- Glaucocystophytes (glaucophyta)
26
Species scape
Each organism's size is proportional to the number of species in that group
27
Cavitation
When an air bubble enters the xylem
28
The Great Oxidation Event
The time in Earth's history, about 2.4 Ga, when the concentration of oxygen in the atmosphere increased dramatically.
29
Cyanobacteria
Were responsible for the Great Oxidation Event (or the “rusting” of the Earth)
They introduced oxygen into the atmosphere
Are oxygenic phototrophs
30
Endosymbiotic theory
The idea that mitochondria and chloroplasts, and possibly other organelles in eukaryotic cells, were once free-living prokaryotes that became part of the cell through a symbiotic relationship (eating each other)
31
Phagocytosis
A form of endocytosis where cells surround food particles and package them in vesicles that bud off from the cell membrane
32
Mitochondria
- The energy factories of the cell
- Has a double membrane
33
Mitochondrial DNA (mtDNA)
Genetic material in the mitochondria of the cytoplasm of a cell; only inherited from the mother. It is haploid and matrilineal
34
Cristi
- The inner membrane of mitochondria
- Is where membrane bound reactions take place
35
Chloroplasts (green)
- Capture energy from sunlight and use it to produce food for the cell.
- They are sites of photosynthesis
- They store chlorophyll
- Double membraned.
- Can be different shapes.
- 5x larger than mitochondria.
36
Endosymbiotic transfer
The process through which chloroplasts and mitochondria relinquish the majority of their genes to the nucleus while not having surrendered the majority of proteins integral to the eubacterial nature of their metabolism
37
Basic requirements for a plant to live
Light, water, carbon dioxide, oxygen, minerals
38
What is the product of photosynthesis
Glucose
39
What adaptations do plants require to survive on land?
Land plants evolved traits that made it possible to colonize land and survive out of water. Adaptations to life on land include vascular tissues, roots, leaves, waxy cuticles, and a tough outer layer that protects the spores.
40
Epidermis
Outer layer of above-ground cells surrounded by a waxy cuticle to prevent water loss
41
Synanthropic pioneer
A plant that lives near and benefits from humans and the artificial landscapes they create
42
Plant cell key features
- Cell wall
- Plasma membrane
- Vacuole
- Cytosol/Cytoplasm
- Nucleus
- Chloroplast
- Mitochondria
- Endoplasmic reticulum
- Golgi bodies
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Totipotency
The ability for single cell to change from one cell type to another and even develop into a whole plant
44
Cell wall components
Cellulose (main component)
Hemicellulose
Pectin
45
Cellulose
A substance (made of sugars) that is common in the cell walls of many organisms. They make up for 30% of the dry weight
46
Hemicellulose
A matrix containing a gluelike substance that holds cellulose fibrils together
47
Pectin
As cells form, the middle lamella (a layer of pectin) is produced first. It is normally shared between two adjacent cells
48
Primary cell wall
consisting of a fine network of cellulose, hemicellulose, pectin and glycoproteins in laid down on either side of the middle lamella
49
Secondary cell wall
When more layers of cellulose are built, it gives more rigidity
50
Lignin
Wood
51
Plasmodesmata
Small channels that directly connect the cytoplasm of neighboring plant cells to each other, establishing living bridges between cell
52
Plasma membrane components
- Lipid bi-layer with hydrophilic ‘heads’ and hydrophobic ‘tails’.
- Proteins and protein complexes.
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Plasma membrane functions
- Detection, transduction and transport of molecules to and from the cell.
- Synthesis of cellulose.
- Formation of intercellular connections
54
Vacuole structure
- Can take up to 90% or more of the volume of a cell.
- Surrounded by a membrane (tonoplast)
55
Vacuole function
- Maintenance of cell pressure and pH.
- Movement of water in and out of the vacuole is involved in controlling turgor pressure of the cell
- Store a variety of things such as water, nutrients, or waste products. Larger in plant cells
56
Turgor pressure
Turgor pressure is the force within the cell that pushes the plasma membrane against the cell wall, no water makes the plant less rigid
57
Nucleus structure
- Has 2 membranes (each has a lipid bylayer) which constitute the nuclear envelope
- The outer envelope is connected with the endoplasmic reticulum, especially the rough ER.
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Nucleus function
- Contains DNA
- Control centre of the cell
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Endomembrane system (Endoplasmic Reticulum)
- Storage
- Cell signalling
- Lipid biosynthesis
- Movement of molecules and proteins
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Endomembrane System (Golgi Apparatus)
- "Post office" packages are dropped of and destinations are assigned
- Proteins sorted
- Glycosylated
- Transfer of proteins
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Endomembrane system
- A group of membranes and organelles in eukaryotic cells that works together to modify, package, and transport lipids and proteins
- It contains the nucleus, endoplasmic reticulum, golgi apparatus, vesicles, and the plasma membrane.
62
Ribosomes
- Site of protein synthesis. It is made up of two sub-units (60S and 40S)
- Ribosomes genes are some of the slowest evolving genes
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Plastids
Plant organelles that make/store food or pigments
- Chloroplasts (green)
- Leucoplasts (white)
- Chromoplasts (other than green)
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Leucoplats (white)
Store starch and oil
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Chromoplats (other than green)
Stores pigments that are responsible for the bright colors in fruit and flowers (other than green)
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Etioplast
Plastids that do not contain chlorophyll because they have been kept out of the light for a period of time.
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Primary producer (Autotroph)
An organism that can synthesize its own food from inorganic sources
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Gross primary productivity (GPP)
Total amount of chemical energy produced in a given area and time period
69
Three main components of plant cell structure
- Microtubules
- Intermediate Filaments
- Microfilaments
70
Cytoskeleton
Determine cell shape, cell division, organelle anchoring and movement
* Network of thread-like proteins found throughout the cytoplasm
Three main components:
* Microtubules
* Intermediate filaments (not well studied in plants)
* Microfilaments
71
Microtubules
- They organize the position of organelle
- Are part of appendages (flagella and cilia) involved in cell motility
- Made up of α and β tubulin proteins
- Stacked in 13 rows to form an alpha helix
- Form a thin, hollow, tube-like structure 15-25
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Intermediate Filaments
Thinner than microtubules (12 nm in diameter)
Hold the nucleus in position and control nuclear shape
73
Microfilaments
- Formed from actin protein
- Organized into helical chains twisted around each other (8 nm in diameter)
- Controls cell shape
- Move cell contents around the central vacuole
- Driven by motor proteins
74
Motor proteins
- Proteins associated with microtubules and microfilaments
- Attach to the cargo to be moved (i.e. transport vesicles going from ER to Golgi)
- These proteins move, release, reattach and move again using ATP
- Motor proteins are a eukaryotic invention allowing for larger cell size and differentiation
