3. Plant Structure and Function Flashcards
What are plants shoots and what do they consist of
Above ground. They have stems and leaves.
What portion does roots have to do with
Below ground
Draw a plant structure diagram
.
What are the function of leaves (4)
Photosynthesis - production of sugar from co2 and h2o in the presence of sunlight. occurs in chloroplast that contain chlorophyll
Storage of food and water.
Leaves have an epidermis (outer layer of cells) covered by a waxy cuticle (prevents water loss). Leaves also have stomata (openings)
Name leaves that store food
Onion. Aloe vera stores water and cactus.
Functions of stems (6)
- Allows for continued growth of plant vertically (indeterminate). Grow for many years = perennial (also means indeterminate). To grow for only one year = annual.
- Provide physical support to the plant
Oldest tree?
Oldest trees are 4,750 yrs old.
Functions of stems (6)
- Allows for continued growth of plant vertically (indeterminate). Grow for many years = perennial (also means indeterminate). To grow for only one year = annual.
- Provide physical support to the plant
- Provide axillary buds that produce side shoots (brussel sprouts)
- Transport water & nutrients up and down plant
- May be used for storage of food & h20
- Allow for lateral growth to increase size of trees in diameter
Oldest tree?
Oldest trees are 4,750 yrs old.
Function of roots (5)
- To anchor plant/tree in soil
- To absorb h20 & nutrients from soil. Roots have a very large SA
- To provide continued growth via root tips (meristem)
- For storage of nutrients e.g. carrots
- Epidermis on root protects the root
Plant cells vs. Animal cells
- Plants have choloroplasts
- Plant cells have thick cell walls
- Plants have vacuoles (storage of water, nutrients, waste products)
Describe plants cell wall
- Multilayered cell wall
- Primary cell wall contains cellulose (chain of glucose molecules)
- Secondary cell wall has lignin and hemicellulose (provides strength and rigidity)
- Cells connected to one another by cytoplasmic connections by plasmodesmata
Function of cellulose and lignin
Thickening and strength
Two species of plants
1) Coniferous species (evergreens) -> gymnosperms (cedar, fir, hemlock, pine)
2) Deciduous species (flowering plants) -> angiosperms (250,000 species)
Two species of plants
1) Coniferous species (evergreens) -> gymnosperms (cedar, fir, hemlock, pine)
2) Deciduous species (flowering plants) -> angiosperms (250,000 species)
Angiosperms are divided into what two categories
Monocotyledons (monocots) & dicotyledons (eudicots)
Differences between monocots and dicots
Monocots have one cotyledon, eudicots have two. Leaf veins on monocot are parallel, but branche on eudicots. Monocot’s flowers come in multiples of 3, dicot’s flowers come in multiples of 4-5. Vascular bundles of monocots are arranged randomly, vascular bundles of dicots are circular. Root system of monocots are fibrous, taproot for dicots.
List 4 types of plant tissue
Meristermatic, Dermal, Vascular and Ground tissue
Describe meristematic tissue
Actively dividing cells, found in growing points (top of plant, root tip)
Continued growth is possible = primary growth
Describe meristematic tissue
Actively dividing cells, found in growing points (top of plant, root tip)
Continued growth is possible = primary growth
Describe dermal tissue
On outside of plant (epidermis)
Protective role
Describe ground tissue
3 types
a) Parenchyma
- most common
- thin walls
- large vacuole
- make food (sucrose) i.e. leaves
- store food (sucrose, starch) i.e. fruits roots
- living cells
b) Collenchyma
- no food production
- supportive function: thicker cell walls
- living cells
- maintain rigidity in plant
- example is celery
c) Sclerenchyma
Describe ground tissue
3 types
a) Parenchyma
- most common
- thin walls
- large vacuole
- make food (sucrose) i.e. leaves
- store food (sucrose, starch) i.e. fruits roots
- living cells
b) Collenchyma
- no food production
- supportive function: thicker cell walls
- living cells
- maintain rigidity in plant
- example is celery
c) Sclerenchyma
- thick cell walls
- very important for support (physical)
- dead cells
- trees and plants grow upright
Describe vascular tissue
2 types
a) Xylem
- transport of h20 and nutrients up the plant
- dead, lignified cells
- provides structural support (trees)
- Main cells are tracheids and vessel elements. Vessel elements are shorter, and are connected together into long tubes that are called vessels
b) Phloem
- transport of sugar to top and bottom of plant
- alive and nonlignified
- Main cell are Sieve Tube Elements that has a sieve plate across top and companion cell beside
Describe vascular tissue
2 types
a) Xylem
- transport of h20 and nutrients up the plant
- dead, lignified cells
- provides structural support (trees)
- Main cells are tracheids and vessel elements. Vessel elements are shorter, and are connected together into long tubes that are called vessels
b) Phloem
- transport of sugar to top and bottom of plant
- alive and nonlignified
- Main cell are Sieve Tube Elements that has a sieve plate across top and companion cell beside
Describe lateral growth
Secondary growth, causes increase in diameter
What is vascular cabium
Actively dividing layer of cells in stems
What is vascular cabium
Actively dividing layer of cells in stems
Describe plant transport
Move water from soil, up stem and leaves Roots take up water and move in xylem Move sugar down from leaves in phloem Root hairs increase SA in absorbtion Nutrients are taken up
Two types of nutrients and describe them
1) Macronutrients
a) needed in high concentrations
- includes nitrogen, potassium, sodium
b) Micronutrients
- needed in low concentrations
- iron, copper, zinc
Describe uptake of nutrients in roots
Anions - negatively charged, easy to take up
Cations - positively charged, binds to soil particles
Describe uptake of nutrients in roots
Anions - negatively charged, easy to take up
Cations - positively charged, binds to soil particles
Release of protons into soil. Cross the cell membrane. Proton pump -> co transport (fig 38.10)
How does water enter root
Apoplast (around cells)
Symplast (through cells)
What is the casparion strip (wax)
Redirects water through cells. Control flow, via symplast.
Characteristics of maple tree
Summer day, 800L/day (30-40 flights), water against gravity
How many stomata per leaf
20,000
3 causes for stomata open
Sunlight
High conc of water
High conc of K+ ions
Describe transpirational pull
Water loss from stomata cause deficit in water higher up the plant.
Describe transpirational pull
Water loss from stomata cause deficit in water higher up the plant. Creates negative tension in leaves. This pulls water up the xylem from the roots, creating a water column. This is called transpirational pull. Column created by hydrogen bonding. If too much water lost in transpiration, stomata close
Adaptations of plants that grow in hot climate (6)
1) Size of leaves are reduced
2) Fleshy leaves that store water
3) Stomata close during the day open at night
4) Stomata positioned deeper in leaves
5) Cuticle thickness increased
These plants are called xerophytes
Describe movement in phloem
- Sugars move from leaves to other parts of plant
- Sinks are locations where sugar is needed
- Source is where sugar is produced (leaves)
- Sugars are in phloem sap (where maple syrup comes from)
How does sucrose move (2)
Sucrose moves via pressure flow. High conc of sugar in leaves. Attracts water into cells. Cells build up pressure. Causes sugar to move down the plant. Sucrose moves in and out of cell using co-transport and ATP pump.
How does sucrose move (2)
Sucrose moves via pressure flow. High conc of sugar in leaves. Attracts water into cells. Cells build up pressure. Causes sugar to move down the plant. Sucrose moves in and out of cell using co-transport and ATP pump.
Female and Male gamates are called
Male - pollen
Female - Ovule
Draw and label flower parts
.
Fertilization end products
Producing a zygote
Producing seeds
Producing fruits
What is double fertilization
Type of fertilization, female gametophyte fertilize with 2 male gametes. 1 pollen nucleus fertilizes with ovule nucleus to form a diploid zygote while the second pollen nucleus fuses with two polar nuclei to form a triploid nuclei, which develops into endosperm.
After fertilization ovules become seeds
Function of endosperm
Has food reserves, used for seed germination
Function of endosperm
Has food reserves, used for seed germination
What is pollination
Transfer of pollen from stamen to the stigma
Two types of pollination
1) Self pollination - Pollen from same flower, lands on the same stigma. I.e. Tomato, pea, wheat
2) Cross pollination - Pollen from another flower lands on the stigma of a different flower. I.e. Apple, cherry
Describe possible movement of pollen
1) Wind I.e. grasses, coniferous trees.
- Produces lots of pollen
2) Insects I.e. Honeybees, ants
3) Animals I.e. Bats, bears, humans
Possible ways seeds are dispered
1) By animals.
- fruit is colourful, juicy I.e. Bears, birds
2) By Wind
- lots of seeds i.e. grasses and trees
3) Seeds with spiny projections
- Human’s clothing, bears, cottonwood
4) By water
- Coconut
5) Aerodynamic seeds
- Maple seeds, dandelion, acacia pod
Possible ways seeds are dispered
1) By animals.
- fruit is colourful, juicy I.e. Bears, birds
2) By Wind
- lots of seeds i.e. grasses and trees
3) Seeds with spiny projections
- Human’s clothing, bears, cottonwood
4) By water
- Coconut
5) Aerodynamic seeds
- Maple seeds, dandelion, acacia pod
Describe self pollination in detail
1) Some plants want to encourage cross pollination
a) Make male and female parts of the same flower on different parts of the same plant
Difference between monoecious and diecious
Dioecious plants are plants where one plant is male with only male flowers and another plant is female with only female flowers. Monoecious plants are those where one plant has both male and female flowers on the same plant or in other words one plant is both male and female.
Difference between monoecious and diecious
Dioecious plants are plants where one plant is male with only male flowers and another plant is female with only female flowers. Monoecious plants are those where one plant has both male and female flowers on the same plant or in other words one plant is both male and female. Corn is monoecious
Example of monoecious and diecious
Corn
Cannibis, hops
What is self incompatibility
Pollen from some flower is inhibited from growing in style.
- Pollen tube is killed
- Pollen from different flower will grow
- S1S2 pollen - S1S2 stigma, no fertilization
Example: cherry trees
Called when plants have 2 sets of chromosomes, 4, 6, 8, and 3
Diploid Tetraploid Hexaploid Octaploid Triploid
Seedless watermelon contain what kind of set
Triploid
Vegetative propagation
a
Vegetative propagation
All plants are genetically identical clones
Vegetative propagation
All plants are genetically identical (clones)
Stolons, are horizontal creeping aboveground stems. These stems travel along the soil surface and can sprout new, genetically identical, plants at nodes along their length. A sucker is a shoot that arises from an adventitious bud on an underground root.
Examples strawberries, Bananas, Potato, Onion, Tulip
Plant response to injury (about 1-2 days)
If a needle broke the cell wall, and causes the cell wall to be in fragments, a receptor detects the signal and binds. More signals are produced, signal transduction. Plant enzyme will repair damage. For example, when cut apple turns brown (oxidizes).
Describe signals produced
Mostly hormones
- effective at low concentrations
- translocated in plant
- specific outcomes
- physiological changes occur
Describe signals produced
Mostly hormones
- effective at low concentrations
- translocated in plant
- specific outcomes
- physiological changes occur
What is it called when produce more cells make cells larger plants taller fruits ripen
produce more cells - auxin
make cells larger - cytokinins
plants taller - gibberellins
fruits ripen - ethylene
What is it called when produce more cells make cells larger plants taller fruits ripen
produce more cells - auxin
make cells larger - cytokinins
plants taller - gibberellins
fruits ripen - ethylene
How does a tree knows its springtime
Sense change in temp & light intensity Trigger hormones and proteins in plant. Fair conditions (lower temp, lower light) -> leaves fall off, hormones lower - chlorophyll is broken down and reabsorbed
How do seeds germinate
- changes in temp and increase in moisture
- levels of gibberellins increase
- increased level of enzyme alpha amylase (breaks down starch to form sugar)
- energy source from sugar
Plants response to light
a) grow towards a source of light (phototropism). due to auxins
b) photoperiod - response to the duration of light induction of flowering
short day plant - needs long nights to flower i.e. poinsettias
long day plant - needs short nights to flower i.e. lettuce
flowering hormone produced -> photochrome (phytoreceptor) : detects light
Plants response to light
a) grow towards a source of light (phototropism). due to auxins
b) photoperiod - response to the duration of light induction of flowering
short day plant - needs long nights to flower i.e. poinsettias
long day plant - needs short nights to flower i.e. lettuce
flowering hormone produced -> photochrome (phytoreceptor) : detects light
Plant responses to environment (8)
- Physical injury/insect injury
- signals are produced (systemin) and receptors detect them -> other signals produced - Changes in temperature
- tree growth - Seed germination
- hormones produced -> enzymes produced - Changes in growth due to hormones
- Response in light
- growth (phototropism) -> towards light source
- in response to duration (photoperiod) -> flowering (photochrome) - Response to gravity
- roots grow towards gravity
- auxins involved, roots have gravity sensing cells - Response to UV radiation
Plant responses to environment (8)
- Physical injury/insect injury
- signals are produced (systemin) and receptors detect them -> other signals produced - Changes in temperature
- tree growth - Seed germination
- hormones produced -> enzymes produced - Changes in growth due to hormones
- Response in light
- growth (phototropism) -> towards light source
- in response to duration (photoperiod) -> flowering (photochrome) - Response to gravity
- roots grow towards gravity
- auxins involved, roots have gravity sensing cells - Response to UV radiation
- plants accumulate pigments which serve as anti-oxidants for protection against UV i.e. green tea, kale - Play music/ talk to plants -> grow better
What are phytosteriods
Chemicals in plants that seem to have activity of estrogen i.e. soybeans
Describe photosynthesis
Most interesting process in nature and most important
- solar energy -> chemical energy -> organic matter (sugar)
- occurs in plants, algae, kelp
- 6Co2 + 12 H20 + light energy -> C6H12O6 + 6O6 + 6H2O
Where is chlorophyll found in
Grana, surronded by thylakoid membrane
Chlorophyll absorbs light energy
Describe light reactions
- Produce energy (ATP, NADPH = nicotinamide adenine dinucleotide phosphate)
Describe light energy used in photosynthesis
- Plants use visible range of light (380-750)
- Blue and red wavelengths are optimal for photosynthesis
- Green light is not used
Describe chlorophyll
- found in chloroplasts
- absorbs light in blue and red wavelengths
- ch
Describe chlorophyll
- found in chloroplasts
- absorbs light in blue and red wavelengths
- chlorophyll “a” and “b”
- also have carofenoids (coloured pigments) -> orange, red, yellow
- has porphyrin ring and hydrocarbon tail
- chlorophyll absorbs light photons. The molecule gets activated (excited) absorbs light energy
- water molecule is split by enzyme to release electrons H+
- electrons are elevated to higher frequency state by chlorophyll
- reactions take place in photosystem (light-harvesting system complex)
- contains chlorophyll, corotid pigments,electrons release
- photosystem I and II
- primary electron acceptor takes electron and transfers them (electron transport chain)
- thylakoid membrane
Difference between photosystem I and II
I absorbs 700nm (far red) P700
II absorbs 680 (red) P680
Descibe Calvin cycle
- Occurs in stroma (liquid) of chloroplasts
- Takes CO2 -> sugars (carbs)
- ATP, NADPH used up
- 160 x 10^12 kg/yr of carbon produced from CO2 (carbon credits)
3 phases
1) Carbon fixation
Ribulose 1,5 - biphosphate (RuBP) 5-carbon + CO2
3 phosphoglycerate
2) Reduction
3) Regeneration
What does RuBisCO stand for
Ribulose-1,5-bisphosphate carboxylase/oxygenase
What are bundle sheath cells
Specialized cells that have RuBisCO and can fix CO2 when CO2 levels are very low
What does CAM stand for
Crassulacean Acid Metabolism
E.g. Cactus
1. Stomata close during day open at night
2. CO2 taken up at night, produces organic acids (crassulacean acids)
3. CO2 released / Stores in cells
4. Day light
5. Light reactions
Compare CAM and C4
C4-Higher energy requirement lower net energy gain offset by higher efficiency at elevated temperatures and lower CO2 concentrations. CAM-Higher energy requirement lower net energy gain offset by lower water loss. Also, stomata closed during day.
Descibe Calvin cycle
- Occurs in stroma (liquid) of chloroplasts
- Takes CO2 -> sugars (carbs)
- ATP, NADPH used up
- 160 x 10^12 kg/yr of carbon produced from CO2 (carbon credits)
3 phases
1) Carbon fixation
Ribulose 1,5 - biphosphate (RuBP) 5-carbon + CO2
3 phosphoglycerate
2) Reduction
3) Regeneration
In fixation, the first stage of the Calvin cycle, light-independent reactions are initiated; CO2is fixed from an inorganic to an organic molecule. In the second stage, ATP and NADPH are used to reduce 3-PGA into G3P; then ATP and NADH are converted to ADP and NADP+, respectively. In the last stage of the Calvin Cycle, RuBP is regenerated, which enables the system to prepare for more CO2 to be fixed.
