NUR 229 Lecture 31: NUR229 Genetics upFINAL Fa19
Document Summary
Dna (deoxyribonucleic acid) is a complex molecule of sugar (ribose), oxygen bonds and proteins (adenine, thymine, cytosine, guanine) in the shape of a double helix. Gene - complex unit of heredity composed of 100 or more base pairs of dna proteins that serve as the blueprint for producing a substance in the body, usually a protein. There may be up to 8 genes for a body characteristic. Chromosome - large unit of heredity composed of thousands of base pairs that control many facets of tissue development and functioning. Nucleotide = pentose sugar, phosphate, purine (a & g) or pyrimidine (t & c) nitrogen base. Nitrogen bases = adenine, thymine, guanine, cytosine (a-t c-g) 22 pairs are somatic cell chromosomes (called autosomes). 23rd pair includes the germ cell sex chromosome. Structure = two chromatid strands connected by a centromere. Corresponding genes on each chromatid = an allele.
