• Genetics – is the scientific study of heredity and the variation of
inherited characteristics.
• It includes the study of genes, themselves, how they function,
interact, and produce the visible and measurable characteristics we
see in individuals and
• populations of species as they change from one generation to the
next, over time, and in different environments.
,Heredity
• Heredity – Humans have always been aware that the characteristics of an individual plant or
animal in a population could be passed down through the generations.
• Offspring look more like their parent.
• Humans also knew that some heritable characteristics (such as the size or color of fruit) varie
between individuals, and that they could select or breed crops and animals for the most favo
traits.
• Knowledge of these hereditary properties has been of significant value in the history of huma
development.
• In the past, humans could only manipulate and select from naturally existing combinations of
genes.
• More recently, with the discovery of the substance and nature of genetic material, DNA, we c
now identify, clone, and create novel, better combinations of genes that will serve our goals.
• Understanding the mechanisms of genetics is fundamental to using it wisely and for the
betterment of all.
, • By the early 1900’s, biochemists had isolated hundreds of different
chemicals from living cells.
• Which of these was the genetic material? Proteins seemed like
promising candidates, since they were abundant, diverse, and
complex molecules.
• However, a few key experiments demonstrated that DNA, rather th
protein, is the genetic material.