أكاديميا - كولنز معاجم الجيب العلمية - البيولوجيا انكليزي - فرنسي - عربي الحرف ٢_ s

Academia - Collins Scientific Pocket Dictionaries - Biology
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Selectively permeable membrane f selection permeable

Selective membrane permeability. Membranes are living structures that surround cells and delimit regions within cells. Membranes are made of regular arrangements of protein and fat molecules. Certain small molecules may pass through pores in the membrane, while larger molecules are trapped. This is why the membrane is described as selective or semipermeable.
See cell osmosis.


semicircular canals
canaux mpl semicircularaires

Semicircular canals. Tubes within the inner ear of vertebrates, important in maintaining balance. See ear.


sense organ
organe m de sens

. Sensitivity and receptor are sensory organs. Look


sensitivity (or irritability)
sensitivity f

Allergy (or irritation). The ability of living organisms to respond to changes in environmental stimuli, such as heat, light, sound, etc. Sensitivity enables organisms to perceive changes in their environment and then make appropriate responses to changes that may occur. Certain parts of animals' bodies, such as eyes, ears, and skin, are sensitive to certain environmental stimuli and are called sense organs or recrptors. Likewise, some plant tissues, such as shoot tips, are receptors, as they are important in tropisms.

environment
Responses
Effectors
receptors
Alarm clocks
behavior

As a result of stimuli coming from the environment, responses are initiated by specialized structures called effectors, such as muscles. The organism's responses shape its behavior.

sensitivity in mammals
Sensitivity to mothers

Mammalian allergies Mammalian receptors are specialized cells connected to the brain or spinal cord, which together make up the central nervous system. The receptors release a nerve impulse - the nerve cells transmit the stimulus to a stimulus, the response of the nerve cells, this impulse to the central nervous system, meaning that the receptor converts the energy of the stimulus into the electrical energy of the nerve impulse.
summary :

Sense - stimulus - future

Smell - chemicals - nose
Taste - Chemicals - Mouth
Touch - touch - skin
Hearing - sound - ears
Sight - light - eyes
Balance - changing position - inner ear

. Taste, smell, skin, eye, and ear, wait


sex chromosome
Chromosome m of sex

Sex chromosome. Any chromosome involved in sex determination. In diploid human cells, there are 46 chromosomes made up of 23 homologous pairs, where one of the pairs is described as sex chromosomes. The female's two sex chromosomes are similar and are called chromosomes. Thus, the female's genotype (XX) is homogametic. In the male, one of the pairs is clearly smaller and is called the chromosome. Thus, the male genotype is XY (heterozygous).

The male is not always heterosexual. In birds, for example, the male is XX and the female is XY, while in some insects the female is XX and the male is XO as the Y chromosome is absent.

In addition to determining sex, the sex chromosomes contain genes that control features or landmarks, which leads to what is known as sex linkage.


sex determination
Determination of sex

Sex determination The method by which the sex of a zygote is determined, and the most common method is determination by sex chromosomes. Let's take the genotypes of a human male and female:

This means that: (a) The sperm of a pregnant woman 7 can fertilize an egg and give rise to a mate whose genotype is XY and whose phenotype is male.
(b) The sperm of an Since half of the semen is X and half is Y, there is an equal chance that the marriage will be male or female.