Structure of Genetic Material
Feb 24, 2016
Structure of Genetic Material
Chromatin
• Genetic material in the nucleus• Made up of DNA and proteins• Thread-like and uncondensed• Appears grainy
Chromosomes
• Genetic material• Formed from condensation of chromatin• Formed during prophases of mitosis and
meiosis I• Consists of a centromere and two identical
replicated strands, called chromatids
Chromatid
• Each of the two identical chromosomes strands
• In a replicated chromosome attached by centromere
Karyotype
• A chart• Number and form of chromosomes in a cell• Determine whether chromosomes of an
individual is normal in number and structure
Homologous Chromosomes
• A pair of chromosomes that each carry genes for the same trait at the same location on the chromosome
• One is inherited from the mother, the other from the father
DNA
• Deoxyribonucleic Acid• Double helix• “Twisted Ladder”• Two sides of the ladder are made up of a
repeating sequence of sugar and phosphate groups
• The rungs of the ladder are composed of a pair of nitrogenous bases– Four bases: Adenine, Thymine, Guanine, Cytosine