1. CHROMOSOMES:  chromosomes are thread-like structures consisting of nucleic and protein , located with the nucleus of the cell.
2. Diploid numbers(2n): the diploid means two of every kinds of chromosomes
3. Haploid number(n): this is when chromosomes occurs singly

Somatic cells  have a diploid number of chromosomes gamete cell have a haploid number(n) of chromosomes. All hhuman being have 46 chromosomes in the body cells is the diploid number half this number of chromosomes found in the gametes fused during fertilisation, the nucleus of the egg and the sperms contribute 23 chromosomes to restore 46 chromosomes