Botany Vocab - Unit 3

Dicot

flowering plants with two cotyledons; for example, beans, peas, sunflowers, roses, and oak trees

Monocot

a flowering plant with one cotyledon; for example, orchids, lilies, palms, onions, and grasses

Simple leaf

a leaf with a single, undivided blade; may be toothed or lobed

Compound leaf

a leaf in which the blade is divided into leaflets

Alternate

a leaf arrangement with one leaf per node

Opposite

a leaf arrangement with two leaves per node

Whorled

a leaf arrangement with three or more leaves per node

Mesophyll

ground tissue located between the upper and lower layers of the epidermis; site of photosynthesis

Guard Cell

one of two epidermal cells on either side of a leaf pore, the combination of pore plus guard cells constitutes a stoma

Stomata

a pore in a leaf regulated by two guard cells; controls movement of water vapor, CO₂, and O₂

Conifer

a tree with needle-like leaves, typically evergreens. They keep their leaves all year round

Deciduous

 an adjective describing plants that lose all their leaves at a certain time of the year

Abscise

the process of a plant shedding one of its parts, like flowers or leaves

Epihyte

a plant that grows on another plant for support but nourishes itself

Hydathodes

a specialized pore, typically found at the leaf margins or tips, that secretes water through a process called guttation

ATP

an organic molecule that is the main energy source for cells; mitochondria breaks down sugar to store its chemical energy in ATP. Photosynthetic light reactions produce ATP, which is used in the calvin cycle

Light Reaction

photosynthetic reactions that occur within thylakoid membranes of chloroplasts. Inputs are light energy and H₂O, outputs are chemical energy of ATP and NADPH and O₂

Calvin Cycle

photosynthetic reactions that assemble simple three carbon sugars, using ATP and NADPH from the stroma of chloroplasts. To make a one three carbon sugar molecule 3 CO₂, 9 ATP,  and 6 NADPH are required

Chlorophyll

 blue- green photosynthetic pigment directly involved in the light reactions. Absorbs light from the blue-violet and red ranges of the spectrum

Chemiosmosis

a process of moving H+ ions across the thylakoid membrane during photosynthesis or respiration, resulting in a release of energy