5. Gregor Mendel (1822-1884), Austrian monk, whose experimental work became the basis of modern hereditary theory.
6. Genes are composed of segments of (DNA) , a molecule that forms the long, threadlike structures called chromosomes . Like chromosomes, genes typically occur in pairs. A gene found on one chromosome in a pair usually has the same locus as another gene in the other chromosome of the pair, and these two genes are called alleles . Alleles are alternate forms of the same gene. Structure of genes
7.
8. Human Male Karyotype This karyotype of a human male shows the 23 pairs of chromosomes that are typically present in human cells. Karyotype: full set of chromosomes contained in a cell.