أكاديميا - كولنز معاجم الجيب العلمية - البيولوجيا انكليزي - فرنسي - عربي الحرف ١_ t

Academia - Collins Scientific Pocket Dictionaries - Biology
English - French - Arabic letter 1_ T


taste
goût m

Taste. tasting. The ability of animals to distinguish flavors. The recptor cells related to taste in humans are taste buds that are sensitive to chemical stimuli, and their presence is limited to the mouth, and the tongue in particular. There are four types of taste buds: those sensitive to sweetness, acidity, saltiness, and bitterness.

Taste map on the tongue

See sensitivity.


taxis
taxi f

attraction . tropism. Transitional movement of a simple organ or cell in response to an environmental stimulus such as light. These movements show a relationship to the direction of the stimulus. Either the movement is towards it (positive)
Or away from it (negative).

Affinities or tropisms are named by adding a prefix indicating the stimulus. Thus, attraction related to light is called phototaxis. Examples of this include:

Paramecium is negatively attracted to the Earth - nega - it swims away from the source of geotactic gravity.

Fruit flies are positively phototactic, meaning they move toward the light.

Many species of spermatozoa are positively chemotactic, meaning they move toward chemicals released by the eggs.


teeth dents fpl

teeth . Built inside the mouths of vertebrates, they are used to bite, tear, and crush food before swallowing it.
Tooth structure

Enamel: a hard material that covers the exposed surface of the tooth (crown), contains calcium phosphate and provides an effective biting surface.
Dentin: Bone-like material that makes up the inside of a tooth.

Pulp: Soft tissue in the center of the tooth that contains blood capillaries that provide the tooth with food, oxygen, and nerve fibers that register pain if the tooth is damaged.

Root: The part of the tooth located inside the gum and buried in the jawbone by a material called cement.

The types of teeth are: incisors, canines, premolars, molars, and carnassials.

See dental formula, omnivore herbivore, carnivore dentition, and


temperature regulation
Regulation of temperature

Temperature regulation in homoiothermic animals is the mechanism related to maintaining body temperature within a narrow range (in humans, for example, about 37°C) so that normal metabolic reactions can take place. Below we list some of the methods of temperature regulation in birds and mammals:

(a) Subcutaneous fat acts as an insulator.
(b) Hair in mammals and feathers in birds trap air, which is a good insulator.
(c) To evaporate sweat from the skin
Mammals cooling effect.
(d) Blood vessels constrict (superficial vasoconstriction) in response to cold, diverting blood away from the surface of the skin and reducing heat loss.

(e) Superficial blood vessels dilate (vasodilation) in response to heat, bringing blood to the surface of the skin and losing heat to the atmosphere.

Vascular skin

Excessive heat loss
Vasodilation (heat response)

Little heat loss\
Vasoconstriction (in response to cold).


tendon
tendon m

Tendon is a ligament of connective tissue that connects muscles to bones.


testa. testa
test m

A raven. An outer protective cloak for the seed, made of
Integuments (plural integuments) of the egg's ovule after fertilization. The cocoon is usually hard and dry and protects the seed from microorganisms and insects.

testcross
Croisement m expérimental

Test chiasm.
See backcross