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

Academia - Collins Scientific Pocket Dictionaries - Biology
English - French - Arabic Letter 2_ N


niche. niche
niche f

A hotbed. The status or way of life of membership within a community. For example: a carnivore and a herbivore may share a habitat, but their modes of feeding mean that they occupy two different habitats.


nitrification
nitrification f

Azotah. nitrification. Soil-nitrifying bacteria convert organic nitrogen compounds, such as ammonia, into nitrates that plants can absorb. Ammonia is first converted into nitrites by Nitrosomonas bacteria, then ammonia into nitrates by the -spe type. see nitrogen cycle.cies Nitrobacter.


nitrogen cycle
Cycle m de l'azote

Nitrogen cycle. Circulation of nitrogen and its compounds in nature. It results mainly from the metabolic processes of living organisms. The following diagram shows the nitrogen cycle:

Animal protein
eaten
Vegetable protein
Knots
Root
Nitrogen in the air
Absorbed by the roots
Denitrification
stabilizing
Nitrogen
Nitrogens
death
Organic residue
Disassemblers
Ammonia
Azota
Azotetate bacteria
Nitrogens
Azota
Nitrogen bacteria


nitrogen fixation
Fixation of the azote

Nitrogen fixation: Certain microorganisms convert air nitrogen into organic nitrogen compounds. Nitrogen-fixing bacteria live either in the soil or air, or in the root nodules of leguminous plants. The activity of these organisms, such as Azotobacter and Rhizobium, enriches the soil with nitrogen compounds.
. See root nodule and nitrogen cycle


normal distribution curve
Correspondence to normal distribution

The regular distribution curve is a bell-shaped curve obtained when measuring continuous variation in a population. See population variation.

nuclear division
division f cellulaire

Nuclear split. See meiosis and mitosis.


nucleic acids
Acids have many nuclei

Nucleic acids are organic compounds found in all living organisms, especially associated with the nucleus of the cell and consisting of subunits called nucleotides.

N S P Nuwaidah
where
P = phosphate group
S = sugar group
N = Nitrogen base

The sugar group in one nuclide can combine with the phosphate group in another nuclide to form a polynucleotide chain:
These polynucleotide chains form the basis of the structure of DNA. Analyze DNA and RNA.


nucleus
noyau m

A brown nucleus found in most cells and containing chromosomes. It is isolated from the cytoplasm by a nuclear membrane, and the chromosomes are only visible during nuclear division. Because chromosomes contain genetic information, the nucleus controls all cell activities through the work of the genetic material, DNA.

nucleus
Cytoplasm
Nuclear membrane
Chromosome (DNA)

nymph
nymph f

virgin . dark-eyed girl . The form of maturity, which is similar to the imago form of certain insects, but is smaller, wingless, and sexually immature. See metamorphosis.