Allele - nucleotide sequence for a specific gene. - arises from mutation

genotype - the types of alleles that a single individual has

Genotype - the physical expression of the alleles a person has.

DNA is replicated during the S phase of the cell cycle, before undergoing mitosis or meiosis.

2. one strand of the double helix is cut, the 2 strands separate from each other and form a small bubble called a replicon.

3. once the helix is open, free ribonucleotides diffuse to regions of single stranded DNA and pair with the base along both strands. they then polymerize and form primer RNA

semiconservative replication - each strand of DNA acts as the template for making the complementary strand

4. replication fork - when the DNA uncoils and separates and looks like a fork

5. finally, each replication fork runs into one of the adjacent replicons; all new DNA are then ligated into new , complete molecules

point mutation - when a single base is converted to another base by any methods.

inversion - a piece of DNA becomes tangled and breaks, when repaired it is put in backwards

somatic mutation - happen in cells that that never lead to sex cells