T Flashcards
Test cross
A genetic cross used to find out the genotype of an organism.
Testis
(plural: testes) the male sex organs where sperm cells and testosterone are produced.
Testosterone
The hormone, produced by testes, that stimulates the development of secondary sexual characteristics in males and the development of sperm cells.
Tissue
a group of similar cells that act together to perform the same function.
Tissue fluid
The fluid that bathes the cells when plasma and some white blood cells pass out of the capillaries.
Toxin
a poisonous substance. Bacteria release toxins as waste products which bring about the symptoms of a diseases, e.g. high fever.
Translocation
The movement of sucrose and amino acids in a phloem.
Transmissible disease
A disease in which a pathogen can be passed from one host to another.
Transpiration
The evaporation from the surfaces of mesophyll cells in leaves followed by diffusion of water vapour through stomata into the atmosphere.
Trophic level
The position of an organisms in a food chain, food web, pyramids of numbers, biomass or energy. (herbivores are primary consumers and form the second trophic level).
Tropism
A growth response by part of a plant to a stimulus, e.g. light or gravity.
Thrombosis
A blood clot that occurs in a vein or an artery.
Tuber
A swollen stem of a potato for food storage and asexual reproduction.
Turgor
The pressure exerted by a plant cell onto its cell wall. Turgid cells are firm because they are full of water; this can support plant organs such as stem.
