Botany

Stem: The main structural axis of a plant that supports leaves, flowers, and fruits, and conducts water, nutrients, and photosynthates.

Internode: The segment of a plant stem between two nodes.

Axillary bud: A bud that develops in the axil of a leaf and has the potential to form a new branch or flower cluster.

Apical bud: The growing tip of a plant where new leaves and stems develop, responsible for primary growth.

Node: The part of a plant stem where leaves, branches, and flowers originate.

Photosynthesis (equation): The process by which plants convert light energy into chemical energy: 6 CO2+6 H2O+light energy→C6H12O6+6 O26 CO2​+6 H2​O+light energy→C6​H12​O6​+6 O2​

Chloroplast: The organelle in plant cells where photosynthesis occurs.

Monocot: A flowering plant with one seed leaf (cotyledon), parallel leaf veins, and scattered vascular bundles.

Dicot: A flowering plant with two seed leaves (cotyledons), net-like leaf veins, and vascular bundles in a ring.

Plant vs. animal cells: Plant cells have cell walls, chloroplasts, and large central vacuoles, while animal cells do not.

Vegetative organs: The non-reproductive parts of a plant, including roots, stems, and leaves.

Roots: The underground part of a plant that absorbs water and nutrients and anchors the plant.

Stems: The plant structures that support leaves and flowers and transport water, nutrients, and sugars.

Leaves: The primary sites of photosynthesis in a plant, consisting of a blade and petiole.

Blade: The broad, flat part of a leaf where photosynthesis occurs.

Petiole: The stalk that attaches the leaf blade to the stem.

Taproot: The main root that grows vertically downward and gives rise to lateral roots.

Lateral root: A root that extends horizontally from the taproot to provide additional anchorage and nutrient absorption.

Root hairs: Small hair-like extensions of root epidermal cells that increase surface area for absorption.

Root system: The entire network of roots in a plant, including the primary root and all lateral roots.

Shoot system: The above-ground part of a plant, including stems, leaves, and flowers.

Reproductive organs: The parts of a plant involved in reproduction, including flowers, cones, seeds, and fruits.

Flower/cone: The reproductive structures of angiosperms (flowers) and gymnosperms (cones).

Seeds: The fertilized ovules of a plant, containing an embryo and stored nutrients, encased in a protective coat.

Fruits: The mature ovary of a flower, containing seeds and often aiding in their dispersal.

Vascular vs. nonvascular: Vascular plants have specialized tissues (xylem and phloem) for transporting water and nutrients, while nonvascular plants do not.

Gymnosperm vs. angiosperm: Gymnosperms are seed plants with exposed seeds (e.g., conifers), while angiosperms are flowering plants with seeds enclosed in fruits.

Pollination: The transfer of pollen from the male anther to the female stigma of a flower.

Vein: The vascular bundle in a leaf that provides structural support and transports water, nutrients, and photosynthates.

Guard cell: Specialized cells that surround and control the opening and closing of stomata.

Stomata: Small openings on the leaf surface that regulate gas exchange and water loss.

Cohesion: The attraction between molecules of the same substance, such as water molecules sticking together.

Adhesion: The attraction between molecules of different substances, such as water molecules sticking to plant cell walls.

Surface Tension: The cohesive force at the surface of a liquid that allows it to resist external force.

Hypertonic: A solution with a higher concentration of solutes compared to another solution, causing cells to lose water.

Plasmolyzed: A plant cell that has lost water and shrunk away from its cell wall due to being in a hypertonic solution.

Hypotonic: A solution with a lower concentration of solutes compared to another solution, causing cells to gain water.

Isotonic: A solution with an equal concentration of solutes as another solution, resulting in no net water movement into or out of cells.

Turgid: A plant cell that is full of water and firm, due to being in a hypotonic solution.

Flaccid/shrunken: A plant cell that is limp and less firm, due to water loss in an isotonic or hypertonic solution.

Polar: A molecule with a distribution of charge leading to positive and negative ends.

Hydrogen bonds: Weak bonds between the positive end of one polar molecule and the negative end of another.

Osmosis: The diffusion of water across a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration.

Concentration gradient: The difference in the concentration of a substance between two regions.

Transpiration: The process of water movement through a plant and its evaporation from aerial parts, mainly leaves.

ABA (abscisic acid): A plant hormone that regulates growth and development, including seed dormancy and response to stress.