Plants Unit Test Study Notes

Types of Plants:

Monocot Properties:
-One Cotyledon (seed leaf)
-Parallel seed veins
-Stem vascular bundles scattered
-Flower pedals multiples of 3 / Dicot Properties:
-2 Cotyledons
-Net like leaf veins
-Vascular bundles arranged in a ring
-Flower pedals multiple of 4

Tissues

/ Epidermis:layer of cells without chloroplasts to protect and absorb liquids
Root Hairs:protection and increase surface area for absorption
Cortex:Bulk amount of cells that stores nutrients with large vacuoles
Endodermis:uniform linked cells around the inner bundle.
-Ensure that the interior of the cell is having items filtered out before it enters
Vascular Cylinder: vascular tissue clumped in the centre that contains xylem and phloem, delivering nutrients up to the upper parts of the plant when required.
/ Order: Zone of Maturation > Zone of elongation > Meristematic Region > Root Cap
Meristems:certain parts of the plants that are actively growing
-Has unspecialized cells for plants
Apical Meristems:meristems at the bottom of cells that grow downward
Lateral Meristems:growth of the plant width wise creating cylinders of new cells
/ Dermal Tissues
-Outer layers
Guard Cell:surrounds the stomata to control it are open or close
Stomata:opening for gas and water exchange
Ground tissue
Parenchyma Cells:guard cells for storage, photosynthesis, and secretion
Collenchyma Cells:thick walls for mechanical support (New plants, open for growth)
Scleremchyma Cells:thicker walls for more support (matured plants)
Transpiration:water that evaporates from the leaves. 99% of water lost through transpiration
Leaf Structure
Role
-Convert energy to food through photosynthesis
-Contribute oxygen into the atmosphere
-Shade
-Provides food for decomposers
Cuticle
-Waterproofing
-Non-living, waxy layer
-Blocks everything from passing through
Epidermis
-External layer, protects the interior tissues
-Responsible for making cuticle
Stoma
-Pore for gas exchange and food transpiration
-Protected by guard cells allowing water to flow
-Seals to keep moisture on hot day for example
-Guard cells are swollen due to high concentration of water inside, less water outside, and the water is escaping. The cell is full of water so it’s full and closes the stoma
Spongy Mesophyll
-Gives off oxygen and has empty space to store oxygen
-Picks up carbon dioxide and filters air
Vascular Tissue
-Xylem and Phloem
-Conduct water and dissolved minerals
-Monocot: parallel
-Dicot: Net like pattern
Palisade
-tall cells that stand upright
-chloroplasts and does photosynthesis
/ Xylem:
-Moves water up
-Long hollow tube of Non living cells
-fluid passes through “Pits” of regions
Tracheids:tapered end of pits
Vessel Elements:Pits with constant width
Phloem
-Living cells
-Companion cells
-Sieve Tube elements
-Sieve Plates
-Multidirectional
-Transports Sugars
/ Photosynthesis : Carbon Dioxide + Water -> (light energy) glucose + oxygen
-Glucose contains CO2, reflects the environment’s concentration of CO2
-Trees that die off will release the carbon dioxide they’ve absorbed back into the atmosphere
Methods of translocation
Root Pressure
-Osmosis
-High solute in water near end of root
-Osmosis has the higher water concentration in soil to go into root
Capillary Action/Cohesion Tension
-Water sticks with other water molecules
-When they leave the stomata, it clings with another water molecule, and the entire strand is pulled up, bringing water up.
Mass Flow Theory
-Sugar goes into the phloem
-Reduces the concentration of water in the phloem
-Water rushes into the
-Pressure builds up and moves the water upwards
Factors Effecting Transpiration
Number of Stomata
Wind
Temperature (Positive Correlation)
Humidity (Negative Correlation)
Light Availability (Positive Correlation)
Water content of soil (Positive Correlation)
Amount of salt in soil (negative correlation)
Roots
-Anchor the plant in place
-Absorb water and nutrients
-Prevent soil erosion
-Store starch
/ Stems
Cortex:irregularly shaped, thin layer under bark
-Vascular Cambium:produces xylem and phloem
-Cork Cambium:creates hard outer coating
Turgor:water filled pith and cortex will expand the stems and supports the plants

Plant Hormones

Hormones:a chemical manufactured by specialized tissues on one part of the body that affects another part of the body.

-Targets tissues with these hormones specialized for each type of external factors

-Based on external factors, each hormone is triggered

Growth Promoter Hormones

Auxins:controls the elongation of cells

-Key for phototrophism

-When there is light, the cells on the opposite side will start to elongate, pushing the plant towards the light source

-Auxins will inhibit root elongation

-Auxins help mature the plant

-Commercial Use: promote root growth, prevents ripening of fruits, and seedless fruits

Gibberellins:works with auxins

-Make cells wider

-Made in apical meristems and chloroplasts

-Fruit, flower, and leaf development

-Commercial Uses: sprayed onto grapes to make them seedless, hence they’re wider

Cytokinins:made in roots

-does cell division and allows cell specialization

-Commercial uses: sprayed on flowers to keep fresh

Growth Inhibitor Hormones

Abscisic Acid:Growth inhibitor

-Blocks growth by closing stoma

-Blocks promoting hormones

-No production of sugars

-used in plants during transport to prevent water loss

Ethylene:causes fruits to ripe

-spreads to ripe other plants as well

-Commercial Uses: picked before ripening, uses CO2 to simulate ethylene to ripe them before sales

Trophisms

Phototrophism:plant’s growth in response to light

Gravitophism:plant’s response to gravity

Thigmotrophism:plant’s response to touch

Chemotrophism:plants response to chemicals

Hydrotrophism:plant’s response to water, moves near to water