botany 4

  • Alteration of generation: The life cycle of plants that alternates between a diploid sporophyte generation and a haploid gametophyte generation.

  • Antheridium: The male reproductive organ in lower plants, producing sperm.

  • Archegonium: The female reproductive organ in lower plants, containing a single egg.

  • Calyptra: A hood-like structure covering the developing sporophyte in some lower plants, typically formed from the archegonium.

  • Capsule: The part of the sporophyte that contains spores; also called sporangium.

  • Dioecious: Having male and female reproductive structures on separate individuals.

  • Diploid: Containing a full set of chromosomes (2n).

  • Elaters: Elongated cells found in the sporangia of liverworts and hornworts that twist and untwist with changes in humidity, aiding in spore dispersal.

  • Enations: Tiny, flap-like photosynthetic structures found spiraling around the stem of whisk ferns.

  • Endodermis: A layer of cells in the vascular tissue of plants, sometimes providing insulation.

  • Fertilization: The fusion of sperm and egg to form a zygote.

  • Foot: The basal part of the sporophyte that attaches to the gametophyte and absorbs nutrients.

  • Gametophyte: The haploid generation in the plant life cycle that produces gametes (sperm and eggs).

  • Gemmae: Small, multicellular asexual reproductive structures found on the thallus of some liverworts.

  • Haploid: Containing half a set of chromosomes (n).

  • Heterospory: The production of two different types of spores, microspores (male) and megaspores (female).

  • Homospory: The production of only one type of spore, which develops into a bisexual gametophyte.

  • Hyphoids: Single-celled, thin tissue structures found in mosses.

  • Megaphyll: A large leaf with complex venation, characteristic of ferns and seed plants.

  • Megasporangia: Sporangia that produce megaspores.

  • Megaspore: A large haploid spore that develops into a female gametophyte.

  • Megasporocyte: A diploid cell within the megasporangium that undergoes meiosis to produce megaspores.

  • Megasporophyll: A modified leaf or leaf-like structure that bears megasporangia.

  • Meiosis: A type of cell division that reduces the number of chromosomes by half, producing haploid cells.

  • Mesophyll: The tissue in the interior of a leaf, containing chloroplasts for photosynthesis.

  • Microatmosphere: A localized climate created by dense plant growth, influencing moisture and temperature.

  • Micropyle: A small opening in the ovule through which pollen can enter for fertilization.

  • Microsporangia: Sporangia that produce microspores.

  • Microspore: A small haploid spore that develops into a male gametophyte.

  • Microsporophyll: A modified leaf or leaf-like structure that bears microsporangia.

  • Mucilage: A viscous fluid produced in the pores of hornwort thalli that houses nitrogen-fixing bacteria.

  • Non-vascular plants: Plants that lack vascular tissue (xylem and phloem).

  • Ovule: A structure in seed plants containing the female gametophyte and egg, which develops into a seed after fertilization.

  • Phloem: Vascular tissue in plants that transports sugars and other organic compounds.

  • Pollen cones: Male strobili (cones) in gymnosperms that produce pollen.

  • Pollen grain: The male gametophyte of seed plants.

  • Pollen tube: A tube that grows from a pollen grain to deliver sperm to the ovule.

  • Prothallus: The gametophyte stage of ferns and some other seedless vascular plants.

  • Protonema: A thread-like or plate-like structure formed after spore germination in mosses and some liverworts, from which the gametophyte plant develops.

  • Resin: An aromatic and anti-septic secretion in some plants, like pines, that prevents fungal growth and insect attacks.

  • Rhizoids: Single-celled or multicellular root-like filaments that anchor non-vascular plants to the substrate and absorb water and nutrients.

  • Rhizome: An underground horizontal stem that can produce new shoots and roots.

  • Seed cones: Female strobili (cones) in gymnosperms that contain ovules and produce seeds.

  • Seedless vascular plants: Plants that possess vascular tissue but do not produce seeds.

  • Sori: Clusters of sporangia on the underside of fern fronds.

  • Sporangium: A structure in which spores are produced.

  • Spore: A haploid reproductive cell that can develop into a new organism without fusion with another cell.

  • Sporophyte: The diploid generation in the plant life cycle that produces spores.

  • Sporophyll: A modified leaf or leaf-like structure that bears sporangia.

  • Stomata: Pores on the surface of leaves and stems that regulate gas exchange.

  • Strobili: Cone-like structures composed of sporophylls arranged in a spiral or whorl; found in some seedless vascular plants and gymnosperms.

  • Thallus: A flattened, undifferentiated plant body, characteristic of some liverworts and hornworts.

  • Vascular tissue: Tissues in plants (xylem and phloem) that transport water, nutrients, and sugars.

  • Whorls: An arrangement of leaves, branches, or flowers in a circle around a stem at a single node.

  • Xylem: Vascular tissue in plants that transports water and minerals from the roots to the rest of the plant.

  • Zygote: A diploid cell formed by the fusion of sperm and egg.