Plant Phys Prac Exam 1

These flashcards cover key vocabulary and concepts related to plant biology as discussed in the lecture.

Meristems

Regions in plants where most cell divisions occur.

Phospholipids

The type of molecule predominantly making up the lipid bilayer of plants.

Trichomes

Epidermal cells on leaves that help protect against herbivory.

Plasmodesmata

Membrane lined channels between living cells that allow solute exchange.

Mitosis

The process through which gametes are produced in the alternation of generations.

Primary Growth

Refers to the elongation of the plant body from the apical meristems.

Tissue Types in Plants

Ground, vascular, and dermal tissue.

Xylem Tracheids and Vessel Elements

Structures that do not retain a membrane lining at maturity.

Osmosis

The net movement of water (H₂O) across a selectively permeable membrane.

Plastid

Organelle that can differentiate into other types depending on location.

Water Potential

The most common unit is Joules per meter³.

it is small and has a dipole to neutralize polar and ionic compounds

Water is a good solvent because:

Adhesion

The force of water molecules hydrogen bonding to a polar surface.

Bulk Flow

The movement of water is primarily achieved through this process.

Transpiration

The process where water vapor is lost through pores in leaves.

The force required to overcome the surface tension in the pits is too great

Why doesn't an embolism in one tracheid usually spread to others?

Closed Stomata

Prevents CO₂ from entering the leaf, causing photosynthesis to stop in wilted leaves.

+0.5 MPa

If the Ψs and Ψp in the soil adjacent to a root hair is -0.1 and -0.5 MPa respectively, and Ψs in the root hair is -1.1 MPa, what is Ψp in the root hair (assume a state of equilibrium)?

Micronutrient Deficiency

Can be severely deleterious to the plant’s growth.

Apoplastic is external to membranes; symplastic is inside cells

What is the main difference between the apoplastic and symplastic routes in roots?

Percentage of water vapor in the air relative to the saturation point

What is "Relative Humidity"?

Mycorrhizal Relationship

A symbiotic relationship where a fungus helps obtain minerals from the soil.

Chlorosis

A condition in older leaves that might indicate nitrogen deficiency.

Exudation of Organic Acids

How plant roots release mineral nutrients from soil particles.

Casparian Strip

If a plant can’t form this, water and solutes could move freely.

Cations tend to form ionic bonds with soil particles.

Which is most true about essential minerals and soils?

Mobile Elements Deficiency Symptom

Do not appear in new growth.

Boron

Which is NOT a plant macronutrient?

Clay Soil

Holds the most water but is hardest for plants to extract water from.

Casparian Strip Function

Ensures selective uptake by forcing ions to pass through cell membranes.

Plants in brackish water must have a more negative internal water potential to absorb water at the same rate.

Two identical plants are taking water up into their roots at the same rate. One plant is growing in soil watered with pristine (pure) rain water, the other is growing in brackish water containing ~10 mM NaCl (Ψs = -0.05 MPa). How is it that both plants can take up water at the same rate?

A lower water potential (drier air) increases the gradient, pulling more water through the xylem via transpiration. Plants regulate this mainly by opening or closing stomata.

How does the water potential in the air surrounding a plant influence xylem transport, and what is the primary way a plant controls this?

Magnesium

Mineral important for Chlorophyll.

Iron

Mineral important for electron transfer.

Potassium

Mineral important for solute potential.

Phosphate

Mineral important for polar head groups of membrane lipids.

Nitrogen

Mineral important for amino acids and proteins.