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DeoxyriboNucleicAcid. Molecular Basis for Inheritance. A. DNA Quick Facts. Most of the time DNA molecules exist as loose coils within the nucleus of a cell, like spaghetti inside a balloon. In this form the DNA is visible only through a high-powered electron microscope.
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DeoxyriboNucleicAcid Molecular Basis for Inheritance
A. DNA Quick Facts • Most of the time DNA molecules exist as loose coils within the nucleus of a cell, like spaghetti inside a balloon. In this form the DNA is visible only through a high-powered electron microscope.
Cell – Chromosome – DNA - Gene Did you know? The length of DNA in a cell, when stretched end-to-end, is over 5.0 meters.
DNA Quick Facts1 • One chromosome can have as little as 50 million base pairs or as much as 250 million base pairs. • There’s a copy of our entire DNA sequence in every cell of our body with one exception. • Our entire DNA sequence is called a genome. • There’s an estimated 3 billion DNA bases in our genome. • Our entire DNA sequence would fill 200 1,000-page New York City telephone directories. • A complete 3 billion base genome would take 3 gigabytes of storage space. 100 Facts About DNA by Dr. Hsien-Hsien LeiPosted August 20, 2007 in DNA Fun, DNA in General
DNA Quick Facts • Over 99% of our DNA sequence is the same as other humans. • Genes are made of DNA. • Genes are pieces of DNA passed from parent to offspring that contain hereditary information. • The average gene is 10,000 to 15,000 bases long. • There are an estimated 20,000 to 25,000 genes in our genome. • If all the DNA in your body was put end to end, it would reach to the sun and back over 600 times.
DNA Quick Facts • Genes make up only about 2-3% of our genome. • The odds that two individuals will have the same 13-loci DNA profile is about one in one billion. • Siblings share 50% of their genes. • A parent and child share 50% of their genes.
B. Structure of DNA • A single DNA molecule consists of a deoxyribose sugar, a phosphate group, and a nitrogen base that are bonded together with covalent bonds. • Nitrogen bases in DNA are double-ringed purines (adenine and guanine), or single-ringed pyrimidines (cytosine and thymine). • The structure of a DNA molecule determines the way DNA functions in a cell.
B. Structure of DNA • The nucleotides in a DNA molecule are arranged in a ladderlike structure called a double helix. • The sides of the ladder consist of alternating sugars and phosphate groups that are bonded together. • The bases pair accordingly: Adenine to Thymine; Cytosine to Guanine
Assignment #1 • Read pp. 324-332 of text. • Do the Explains (4) on p. 327, 328, 330 • Identify p. 329 • Do #1-6 p. 332