Botany

The biochemical process by which plants, algae, and some bacteria convert light energy, carbon dioxide, and water into glucose and oxygen. It occurs primarily in the chloroplasts using pigments such as chlorophyll and proceeds through the light-dependent reactions and the Calvin cycle.

Plant cells are eukaryotic cells distinguished by a rigid cellulose cell wall, a large central vacuole, and plastids (including chloroplasts). These features give plants structural support, turgor pressure for growth, and the ability to carry out photosynthesis.

Xylem and phloem are the two primary vascular tissues in plants. Xylem transports water and dissolved minerals upward from roots to shoots, while phloem distributes sugars and organic compounds from photosynthetic tissues to the rest of the plant.

Chemical signaling molecules produced in small quantities that regulate plant growth and development. The five classical groups are auxins, gibberellins, cytokinins, abscisic acid, and ethylene, each controlling processes such as cell elongation, seed germination, and fruit ripening.

The science of naming, describing, and grouping plants into hierarchical categories based on shared evolutionary relationships. Modern plant taxonomy integrates morphological, anatomical, and molecular (DNA sequence) data to construct phylogenies.

Transpiration is the evaporation of water from plant surfaces, primarily through stomata on leaves. It drives the transpiration-cohesion-tension mechanism that pulls water upward through the xylem and helps regulate leaf temperature.

Plants reproduce through both sexual (involving meiosis, pollination, and seed formation) and asexual (vegetative propagation) means. Angiosperms produce flowers as reproductive structures, while gymnosperms use cones and other mechanisms.

Plant ecology studies the relationships between plants and their environments, including interactions with other organisms, nutrient cycling, succession, and the formation of biomes. Plants are the structural foundation of most terrestrial ecosystems.

Phototropism is the directional growth response of a plant toward or away from a light source, mediated by the redistribution of the hormone auxin. Plants also exhibit gravitropism, thigmotropism, and nastic movements in response to various stimuli.

The study of heredity and gene expression in plants, including Mendelian inheritance, polyploidy, gene regulation, and genome-wide analyses. Gregor Mendel's foundational experiments with pea plants launched the entire field of genetics.