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soil texture
texture f du sol

Soil composition. Types of inorganic soil particles and their proportions, of which four types are distinguished according to size.
clay
salt
sand
Pebbles
> Increasing particle size

Soil composition has an important effect on its properties, such as water conservation and aeration, see soil types.


soil types mpl du sol

Soil types. There are many types of soil that can...
They are simply classified into three distinct types:

(a) Sandy (light) soil: It has a high percentage of large inorganic particles, and therefore larger air spaces. Thus, the sandy soil is well ventilated and has good drainage, but it loses mineral salts, which are washed down (leaching).

(b) Clay (heavy) soil: It has a high percentage of small particles, which means that it retains water and materials, but it has poor ventilation and may become burdened with water.
(c) Loam soil: the most fertile soil and consists of a balance of particle types and a good content of humus. Soil of this type is well ventilated and drains freely, while retaining water and minerals.


solution
solution f

The mixture solution (usually a liquid) formed when one substance (solute) is dissolved in another (solvent).
That is: solute + solvent → solution
Example: sugar + water → sugar solution


species
espèce m

Type . A unit used in the classification of organisms that describes any group that shares the same general physical characteristics and can interbreed and produce fertile offspring. For example: All dogs, despite their diversity in shape, size, etc., are of the same type, while horses and donkeys are of two different types within one genus.


spermatozoon (or sperm)
spermatozoide m. spermatula m.

Mona . A small mobile male gamete that forms in the testes of the animal and usually has a flagellum that releases semen from the male to fertilize the female bride.
See meiosis and fertilization


sphincter
sphincter m

sphincter. A muscular ring around tubular organs, the contraction of which narrows or closes the passage inside the organ.
For example, the anal sphincter and the pyloric sphincter
See digestion.


spinal cord
Moelle fépinière

Spinal cord. Part of the central nervous system - cen tral nervous system - is located inside the spine, which protects it. The spinal cord is a cylindrical mass of nerve cells that connects to the brain and other parts of the body via spinal nerves. The spinal cord consists of three regions:

(a) An inner layer of gray matter consisting of coll endoneurons.
(b) An outer layer of white matter consisting of nerve fibers extending along the spinal cord.

(c) Central canal filled with fluid.

The spinal cord transmits nerve impulses to and from the brain and also plays a role in reflex actions.


spiracle
soupirail m. event m

An outlet. A breathing hole is one of many pores in an insect's cuticle that connects the tracheae to the atmosphere.
. gas exchange (insects) See


spleen
rate f

spleen. An organ in the abdomen near the stomach in most vertebrates. The spleen produces white blood cells, destroys worn-out red blood cells, and filters foreign bodies from the blood.