B1 Genes 0.0 / 5 ? BiologyDNA and inheritanceGCSEOCR Created by: TamiCreated on: 28-03-16 22:00 What are Genes? Genes carry instructions that control how you develop and function. They do this by telling the cells to make proteins needed for your body to work. 1 of 18 Where are genes found in a cell? The nucleus 2 of 18 A gene is a section of what? DNA (A gene is a section of a very long molecule of a chemical called DNA or deoxyribonucleic acid) 3 of 18 Lengthe of DNA are packed into structures called? chromosomes 4 of 18 How many genes are there approximately on our chromosomes? between 20,000 and 25,000 5 of 18 Strands of DNA are made of four chemicals called? bases 6 of 18 Name the two groups of proteins? functional proteins and structural proteins 7 of 18 What do functional proteins do? They enable the body to function. E.G enzymes, antibodies and hormones 8 of 18 What do structural proteins do? They give the body structure, rigidity and strength. E.G collagen in ligaments and keratin in skin 9 of 18 What is a genotype? This is a person's genetic makeup 10 of 18 What is a phenotype? This is a person's observable physical features 11 of 18 Put the following in order of size; nucleus, cell, chromosomes, base, DNA, gene (Cell)->(Nucleus)->(Chromosomes)->(DNA)->(Gene)->(Base) 12 of 18 How many pairs of chromosomes are in a human cell? 23 pairs or 46 chromosomes 13 of 18 What are the sex cells? Eggs (Ova) and Sperm 14 of 18 How many chromosomes does a sperm have ? 23 chromosomes 15 of 18 How many chromosomes does an egg (ova) have ? 23 chromosomes 16 of 18 How many chromosomes does a zygote have (a fertilised egg)? 46 chromosomes (23 pairs) 23 from the mother + 23 from the father = full set of 46 chromosomes 17 of 18 What are alleles? Alleles are the different forms in which the genes controlling a characteristic can occur. 18 of 18
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