Exam 1 Flashcards
Root Cap
Primary Root
Root
Secondary Root
Vascular Cylinder
Hypocotyl
Cotyledon
Leaf
Petiole
Midvein
Vein
Margin
Internode
Shoot
Node
Axillary Bud
Terminal Bud
Root (Radicle)
Seminal Root
Caryopsis (Seed)
Mesocotyl
1st Node
Nodal Roots
Coleoptile
1st Collar
1st True Leaf
1st Node to 1st Collar
Shoot (Plumule)
Tip of Shoot
Root Cap
Apical Meristem
Zone of Elongation
Zone of Maturation
Endodermis
Epidermis
Root hairs
Vascular Cylinder
Epidermis
Palisade Mesophyll
Spongy Mesophyll
Veins (Vascular Tissue)
Stomate
Cell Wall
Plasma Membrane
Vacuole
Chloroplast
Mitochondria
Roughh Endoplasmic Reticulum
Nucleus
Osmosis
The property of water passing through a semipermeable membrane with the tendency of eventually equalizing the water potential in the two compartments
Diffusion
Net movement of anything generally moving from a region of high concentration to a region of low concentration
Aquaporins
Membrane protein channels or pores controlling the selective movement of water primarily
Function of a Aquaporin
Bidirectional transfer of water and small solutes across cell membranes
Osmoregulation
The process of regulating the osmotic properties of plant cells
Physiological Importance of Osmoregulation
Maintain a fixed concentration of cell membrane imperable molecules and ions in the fluid that surrounds cells
Osmotic Potential (Ys)
The change in free energy or chemical potential of water produced by solutes; carries a negative (minus) sign
Also called solute potential
Osmotic Pressure (pie)
The pressure developed by a solution separated from pure water by a differentially permeable membrane; it is generally an index of the solute concentration of the solution
Cavitation
A process of rapid formation of bubbles in the xylem
Phosphorus Deficiency
Stunted
Dark green leaves
Older leaves brown
Anthocyanin accumulation in leaves
Phosphorus Deficiency Roles
H2PO4- / HPO42-
Nucleic acids/Phospholipids/Energy Transfer
Toxicity → Root grwoth prolific
Nitrogen Deficiency
General chlorosis to light brown under extreme deficiency
Older leaves may drop
Stunting of growth
Nitrogen Deficiency Roles
NO3- / NH4+
Component of amino acids/nucleic acids/chlorophyll/hormones
Toxicity:
Vegetative growth dark green color
Reduced root growth
Potassium Deficiency
Chlorosis or mottling in older leaves
Necrotic lesions
Stems shortened and weakended - lodging
Potassium Deficiency Roles
K+
Osmotic Regulation:
Enzyme activation - photosynthesis
Guard cell and leaf movement
No known structural role
Toxicity → Rare/Salt Stress
Calcium Deficiency
Meristems and young leaves necrotic
Roots become ‘slippery’
Calcium Deficiency Roles
Ca2+
Cell division - microtubules
Calcium pectates - cell wall formation
Membrane stabilization
Hormonal regulation
Enzyme activation
Toxicity → Reduced availability of iron and micronutrients
Magnesium Deficiency
Older leaves interveinal chlorosis
Necrotic spots
Patches of yellow or orange
Magnesium Deficiency Roles
Mg2+
Chlorophyll
ATP energy usage
Enzyme activation - Rubisco PEP carboxylase
Toxicity
Reduced growth
Serpentine soils
Iron Deficiency
Interveinal chlorosis in younger leaves
Leaves becoming white
Necrosis
Iron Deficiency Roles
Electron transport - heme
Chlorophyll synthesis
Toxicity → Rare - easily precipitated
Essential Nutrients
Nutrient elements that are required by plants in order to successfully complete their life cycle
Beneficial Nutrients
Nutrients that are beneficial to the growth and development of some plants but have not been shown to be requirements of all plants
Macronutrients
Nutrient elemeents that are required in excess of 10 mmole kg-1 of dry weight
Micronutrients
Nutreints that are required in relatively small quantities
(less than 10 mmole kg-1 of dry weight)
Transpiration
The loss of water vapor by plants; most transpiration occurs through open stomata
Which part of a root shows the greatest activity of nutrient uptake
Root hairs and zone of maturation
Passive Transport
Type of membrane transport that does not require energy to move substances across the cell membranes
Active Transport
Requires cellular energy to achieve the movement
The movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration
Facilitated Diffusion
the process of spontaneous passive transport of molecules or ions across a biological membrane via specific transmembrane integral proteins
Soil Plant Atmosphere Continum (SPAC)
Near surface environment in which water and energy transfer occurs from the soil through the plant to the atmosphere
Symplastic Pathway in Water Movement
Occurs during the night
Slow/Much Resistance
Water passes across from one living cell to another living cell
Apoplastic Pathway in Water Movement
Occurs during the day
Fast movement/Little Resistance
Water moves from cell to cell through the intercellular spaces of walls of the cells
Where in the root is most active in water uptake
Root hairs
Cohesion
Strong mutual attraction between water molecules resulting from hydrogen bonding
Adhesion
Same forces that attract water molecules to each other will also attract water to solid surfaces
Hydrogen Bonding
Water remains a neutral molecule but the separation of partial negative and positive charges generates a strong mutural (electricl) attraction between adjacent water molecules or between water and other polar molecules
Biotic Stress
A biological insult (e.g. insects, disease) to which a plant may be exposed
Abiotic Stress
A physical (e.g. light, temperature) or chemical insult that the environment may impose on a plant
Function of the Root Cap
Protects the root from environmental stress and functions in gravity perception
Function of the Primary Root
Absorb water and dissolved minerals from the soil
Function of the Secondary Root
Provide additional support
Storage Food
Absorption of atmospheric moisture
Function of the Vascular Cylinder
Ensuring the key nutrients, water and other substances are transported throughout the plant
Function of the Hypocotyl
Pushes the cotyledons above the ground to develop
Function of the Cotyledon
Help supply the nutrition a plant embryo needs to germinate and become established as a photosynthesis organism
Function of the Leaf
Produce food for the plant by photosynthesis
Function of the Petiole
Pipeline through which the products of photosynthesis are moved from individual leaves to the rest of the plant
Function of the Midvein
Contributes to the bending of the blade such that the center of the leaf faces sunlight
Function of the Vein
Support for the leaf and transport both water and minerals (xylem) and food energy (phloem)
Function of the Margin
Way of telling average temperature by looking at the shape of the leaves
Function of the Internode
Link the nodes of a plant together
Function of the Shoot
Uses the root system to draw up water and nutrients and deliver them to where they need to go in the plants leaves
Function of the Nodes
Site of great cellular activity and growth
Function of the Axillary Bud
Provide propagation material and generate flowering shoots
Function of the Terminal Bud
Causes the shoot to grow longer
Produce hormones that move downward along the shoot, inhibiting the growth of other buds on that shoot
Function of the Seminal Root
Help anchor the young seedling and provide it with nutrients and water
Function of the Mesocotyl
Pushing the coleoptile to the soil surface
Function of the Nodal Root
Providing the majority of the water and nutrients the corn plant needs for growth and development after V4
Function of the Coleoptile
Help in the emergence of the first leaf by protecting it during its passage through the soil
Function of the Apical Meristem
Divison and growth in the root and shoot tips
Function of the Zone of Elongation
Where the newly formed cells increase in length thereby lengthening the roots
Function of the Zone of Maturation
Protection
Storage
Conductance
Function of the Endodermis
Apoplasmic barrier for selective nutrient uptake
Function of the Epidermis
Provide a protectice varrier against mechanical injury, water loss and infection
Function of the Palisade Mesophyll
Photosynthesis since it contains large amount of chloroplast
Function of the Spongy Mesophyll
Efficient gas exchange
Function of the Stomata
Take in carbon dioxide and release oxygen
Function of the Cell Wall
Provides tensile strength and protection against mechanical and osmotic stress
Function of the Plasma Membrane
Provides protection for a cell
Function of the Vacuole
Helps maintain water balance
Function of the chloroplast
Allow plants to capture the energy of the sun in energy-rich molecules
Function of the Mitochondria
Generate most of the chemical energy needed to power the cell’s biochemical reactions
Function of the Rough Endoplasmic Reticulum
Produce proteins for the rest of the cell to function
Function of the Nucleus
Controls and Regulates the activities fo the cell
