Introduction to Plants

Alternation of Generations  -  The fluctuation between the diploid (sporophyte) and haploid (gametophyte) life stages that occurs in plants.

Angiosperm  -  A vascular flowering plant in which seeds are enclosed inside of protective ovaries.

Autotroph  -  An organism that synthesizes its own organic nutrients and does not rely on other organisms for food.

Bryophyte  -  A lower terrestrial plant (often a moss or liverwort) that lacks a vascular system and is dependent on environmental moisture for reproductive and nutritive functions.

Bulb  -  Roughly spherical underground bud containing additional buds that can develop asexually into new plants.

Chlorophyll  -  A green pigment, necessary for photosynthesis, that is found in the chloroplasts of plants.

Dicot  -  An flowering plant (angiosperm) that possesses two cotyledons during embryonic development.

Diploid  -  Having two sets of chromosomes, one from each parent.

Gamete  -  A haploid sex cell (either an egg or sperm cell); male and female gametes join during fertilization to create a diploid zygote.

Gametophyte  -  A haploid plant or plant structure that produces haploid gametes through mitosis.

Grafting  -  An artificial form of vegetative propagation in which parts of two young plants are joined together, first by artificial means and then by tissue regeneration.

Gymnosperm  -  A vascular non-flowering plant (commonly known as a conifer) in which seeds are not protected by an ovary.

Haploid  -  Having only one set of chromosomes.

Hormone  -  A chemical that affects the ways in which an organism functions; it is produced in one part of the plant body but, by traveling to target cells throughout the body, affects many other parts as well.

Jacket Cell  -  A component of the cell layer that covers the reproductive organs of plants and prevents them from drying out.

Monocot  -  A flowering plant (angiosperm) that possesses one cotyledon during embryonic development.

Ovary  -  In plants, the protective structure that holds the ovules and surrounds the angiosperm seed; after fertilization, develops into a fruit.

Ovule  -  Structure that contains the female gametophyte and gametes; after fertilization, develops into a seed.

Phloem  -  Vascular tissue composed of cells that are living at maturity; transports the products of photosynthesis throughout the plant body.

Photosynthesis  -  The process by which plants and other autotrophic organisms convert light energy into organic materials.

Pollen Grain  -  The male gametophyte of gymnosperms and angiosperms.

Root  -  The part of a plant beneath the soil; responsible for collecting water and minerals from the soil, storing nutrients, and securing the plant to the ground.

Root Hair  -  An outgrowth of a plant root that provides an increased surface area for the absorption of water and dissolved minerals from the soil.

Runner  -  Slender horizontal stem that can give rise, via specialized nodes, to new plants.

Shoot  -  The part of the plant above the soil, including all aerial structures such as stems, leaves, flowers, and fruits; gathers carbon dioxide and light energy for photosynthesis, provides surfaces for gas exchange, and contains the plant's reproductive organs.

Sporophyte  -  A diploid plant or plant structure that produces haploid spores through meiosis.

Stoma  -  A very small epidermal pore, surrounded by two guard cells, through which gases diffuse in and out of a leaf.

Tracheophyte  -  A terrestrial plant with a vascular system.

Tuber  -  Fleshy underground storage structure, composed of an enlarged portion of the stem, that has on its surface buds capable of producing new plants.

Vascular System  -  Mechanism of internal water and nutrient transport, made up of the vascular tissues xylem and phloem, that is characteristic of tracheophytes.

Vascular Tissue  -  A conductive component (either xylem or phloem) of the system that transports food and nutrients throughout the plant body.

Vegetative Propagation  -  A form of asexual reproduction in which plants produce genetically identical offshoots (clones) of themselves, which then develop into independent plants.

Xylem  -  Vascular tissue composed of cells that are dead at maturity; transports water and dissolved minerals upwards from the roots to the shoot.