KEY WORDS

The process of genetic transmission of traits from parents to offspring.

Gametes are an organism's reproductive cells. They are also referred to as sex cells. Female gametes are called ova or egg cells, and male gametes are called sperm. Gametes are haploid cells, and each cell carries only one copy of each chromosome.

Having two sets of chromosomes or double the haploid number of chromosomes. The diploid number, 46 in humans, is the normal chromosome

Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells. This process is required to produce egg and sperm cells for sexual reproduction.

An allele is a variant form of a gene. Some genes have a variety of different forms, which are located at the same position, or genetic locus, on a chromosome. Humans are called diploid organisms because they have two alleles at each genetic locus, with one allele inherited from each parent.

An unborn or unhatched offspring in the process of development, in particular a human offspring during the period from approximately the second to the eighth week after fertilization (after which it is usually termed a fetus).

A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

An organism or cell, or group of organisms or cells, produced asexually from one ancestor or stock, to which they are genetically identical.

The division of a cell into two daughter cells with the same genetic material.

A unit of heredity which is transferred from a parent to offspring and is held to determine some characteristic of the offspring.

When a cell has a single set of unpaired chromosomes.

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur. It has a double membrane, the inner part being folded inwards to form layers

A diploid cell resulting from the fusion of two haploid gametes;

A thread-like structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.

A self-replicating material which is present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information.

The central and most important part of an object, movement, or group, forming the basis for its activity and growth.