Variation - differances in a species because different genetic information in their cells.
Genetic information is stored by genes, which are arranged on chromosomes.
Cells have a Nucleause, in the nucleause is the DNA, in the DNA is the chromosomes, the chromosomes have genes, and the genes have alleles.
DNA is shaped as a spiral staircase, also known as a "Double Helux".
People have over 6 trillion cells in their bodies. Every cell has 46 chromosomes, put iin 23 pairs.
Sexual Reproduction involves organisms of the same species. Each organism produces a GAMETE (egg and sperm).
In plants Gametes are egg and pollen. Plants can reproduce ASEXUALLY. The offspring are genetically identical to the parent plant, and are called clones.