Genetics is the study of genes, genetic variation, and heredity in living organisms. A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins.
The Human Genome Project has estimated that humans have 20,000 - 25,000 genes. Every person has two copies of each gene, one inherited from each parent. Most genes are the same in all people, but less than 1% of genes are slightly different between people. Poplar tree genome suggests more than 45,000 genes.
Fruit and vegetable consumption is a focus of research and nutrition education, but there is no universal agreement on the meaning of 'fruits and vegetables'. Foods that require specific instruction include rice, dried beans, potatoes, tomatoes and fruits and vegetables in mixtures and condiments.
Fruit and vegetables are important components of a healthy diet, and their sufficient daily consumption could help prevent major diseases. A recently published WHO/FAO report recommends a minimum of 400g of fruit and vegetables per day (excluding potatoes and other starchy tubers) for the prevention of chronic diseases such as heart disease, cancer, diabetes and obesity, as well as for the prevention and alleviation of several micronutrient deficiencies.
Fruits and vegetables are universally promoted as healthy. The Dietary Guidelines for Americans 2010 recommend you make one-half of your plate fruits and vegetables.
Fruits and vegetables include a diverse group of plant foods that vary greatly in content of energy and nutrients. Fruits and vegetables supply dietary fiber, vitamins and minerals to the diet and are sources of phytochemicals (phytonutrients) that function as antioxidants, phytoestrogens, and antiinflammatory agents and through other protective mechanisms.