أكاديميا - كولنز معاجم الجيب العلمية - البيولوجيا انكليزي - فرنسي - عربي الحرف ٣_ m

Academia - Collins Scientific Pocket Dictionaries - Biology
English - French - Arabic letter 3_ M


mitosis
mitose f

Mitosis. The process in which the nucleus of a cell divides in such a way that the daughter cells receive the number and types of chromosomes exactly identical to those of the parent cell. During this type of nuclear division, the chromosomes of the mother cell (the dividing cell) are first duplicated and then expressed in two identical groups to the two daughter cells.

Chromosomes
nucleus
Central

Chromosomes look like coiled threads. Outside the nucleus you see two structures called centrioles.

Aksumi Centre.
Sogbaid pair
Centriole separation

Each chromosome makes a copy of itself. These copies, or chromatids, join at the centromere.

spindle fibres

The nuclear membrane disappears and the centrioles move towards two opposite poles of the cell and produce a network of fibers called a spindle. The pairs of chromosomes are aligned at the equator of the cell.

Chromosome pairs separate and move toward opposite poles of the cell.

A new nuclear membrane forms and the cytoplasm begins to divide.

The two daughter cells

The chromosomes disappear and the cells return to resting mode.


molars
molaires fpl

Single molars ( molar ). These teeth, collectively known as cheek teeth, are broad, crowned grinding teeth at the sides and back of the mouth used to crush food before swallowing it. Molars are found in ommivores and herbivores, and are replaced by carnassial teeth in carnivores. See dentition and dental formula.


molecule
molécule f

molecule. The smallest complete part of a chemical compound that can participate in a reaction. Atoms are found within a molecule in fixed proportions.


monocotyledons
monocotylédones fpl

Monocots. The smaller of the two subgroups of flowering plants, the other is dicotyledons. The advantages of monocots are:
One cotyledon per seed.
Parallel veins in leaves.
Narrow leaves.
Various vascular bundles in the stem.

The flower parts are usually triple or multiple
The three.
Examples include: grains and herbs.


monohybrid inheritance
Hérédité f monohybrid

Monohybrid inheritance. Inheritance of one pair of opposite traits.
For example: In the fruit fly Drosophila, one of the variants is pure-breeding with normal wings, and the other is pure-breeding with normal wings, and the other is pure-breeding with wings, where the normal-wing allele is dominant over the arch-wing allele.

The following drawing shows the result of crossing between normal-winged females and arch-winged males.

The approximate percentage in the second generation

Normal / Artifact Suite = 1/3

When normal wings intersect with archaic wings, the archaic feature appears to have disappeared, but it appears again in a limited manner in the second generation, which suggests that the first generation, F generation, has treated this feature without showing it. A feature such as the normal wing, which always appears in a cross between two opposite parents, is called dominant, while a feature such as the recessive wing, is lost in the progeny of the first generation and is apparently masked by a dominant feature called recessive.

For each feature, the organism receives one gene from a male gamete and another from a female gamete, meaning that the zygote and the resulting organism contain two genes for each feature, while the gametes each contain only one gene (as a result of meiosis). If the two genes paired for a particular feature are identical, the organism is described as homozygous or pure for that feature. When an organism has two different genes for a trait, it is described as heterozygous or hybrid. Alternative forms of genes are described as anti-allele. Thus, if the antidote of a normal wing is represented by the letter V and the antidote of an archaeological wing by the letter V, we find that:

The VV is a regular homozygous wing
Vv is a plain heterozygous wing
The vv is a homozygous archaeological suite

Organisms that are homozygous for a particular feature produce only one type of puppet for that feature, while heterozygous organisms produce two types of puppets. Then it is possible to know the results of fertilization using the punnet square genetic table. See incomplete inheritance and backcross.