• What is a gene?
• What does a chromosome consists of? (Describe it's features during prophase)
• What is a Locus (loci-plural)
• Genes for a specific trait are always found where? (Use technical terms)
• What do offspring of sexually reproducing organisms have a copy of?
• Label the following diagram?
• What are these pairs called?
• What are the two reason to why they are different?
• Worked out image

Alleles: Versions of Genes

• What is an allele?
• Give an example
• How many alleles do sexual reproducers always inherit for each trait (like eye alleles, skin colour etc)?
• Where should alleles inherited from parents always have to be present in?

Cystic Fibrosis

• At some point in human history, a mutation occurred in the gene that codes for mucus production. This version of the gene (an allele) is what?
• If a person receives two copies of recessive mutated allele, they develop what?

One Base can make a big difference