Inheritance

• Mitosis one cell is copied into 2 identicle cells
• Human sperm and egg cells contain 23 single chromosomes each
• Mitosis produces identicle cells
• Meiosis produces non-identical cells
• 1st stage of meiosis all of the chromosomes are copied
• 2nd stage of meiosis cell divides to 2
• 3rd stage of meiosis 4 haploid daughter cells
• 4th stage of meiosis 2 more divisions occur so that there are 8 haploid cells
• DNA consists of 2 strands of DNA and each one is a polymer
• DNA is a double helix structure
• Normal human cells contain 2 copies of every chromosome
• Alleles are version of a gene
• Cystic fibrosis is recessive and Polydactyly is dominant
• XY is male and xx is female
• A gene is a section of DNA which controls part of a cell's chemistry - particularly protein production.
• The genotype is the combination of alleles (forms of the gene) that a person has for a particular trait.