Genetic Information How are chromosomes genes and DNA

Genetic Information • How are chromosomes, genes and DNA related? • What are their roles as repositories or “keepers & transmitters” of genetic information? Its like the instruction book for life.

DNA Chromosome Cell Gene

Chromosomes • packages of DNA • located in cell nucleus • has specific # of chromosomes – 46 in humans • always come in a pair – so 23 pairs of chromosomes in humans

DNA • deoxyribonucleic acid • chemical building blocks of life • they carry instructions for diversity • contained in chromosomes • packaged as a spiral ladder called a double helix

• DNA molecules are made up of nucleotides – legs of the ladder are made of phosphate and sugar – rungs of ladder are made up of 4 types of nitrogen bases, found in pairs • guanine (G) & cytosine (C) • adenine (A) & thiamine (T) – these rungs form a code … the instructions for what a cell should do or be

Genes • part of the DNA that carries genetic information & is responsible for inherited traits • exist in pairs called ALLELES – each trait has its own pair or alleles – alleles are responsible for variation • dominant traits will overshadow recessive traits • recessive traits will only show up of no dominant traits are present in the allele pair

Chromosomes – are like a computer that stores and manages your bodies genetic information. DNA is like the folder where you’ve put the instructions for a cell (what it is and should do) Genes are like the individual files… they have the details on exactly how to do things, and when.