Memory Anchor:

• Super Challenge:

  Stretch:

  Challenge:

Key Questions:

1. What is the definition for gamete?
   • The male and female sex Cells (sperm and egg)
2. What is the definition for a chromosome?
   • thread-like strcutures in the Cell nucleus that contain DNA
3. What is the definition for a allele?
   • different forms of a gene
4. What is the definition for a dominant?
   • an allele that is expressed when one or two copies are present, represented with a capital letter
5. What is the definition for a recessive?
   • two copies of a recessive allele must be present for the characteristic to be expressed, represented by lowercase letter
6. What is the definition for a homozygous?
   • where two alleles that are the same for a characteristic
7. What is the definition for a hetrozygous?
   • where two different alleles for a characteristic
8. What is the definition for a genotype?
   • the alleles present for a particular gene
9. What is the definition for a phenotype?
   • the characteristic that is shown or expressed
10. Give two examples of characteristics that are controlled by a single gene
    • 1. fur colour in mice 2. red-green colour blindness in humans
11. How are genotype and phenotype related?
    • The alleles present, or genotype, operate at a molecular level to develop characteristics that can be expressed as a phenotype.
12. What is the phenotype when there is a dominant allele?
    • A dominant allele is always expressed, even if only one copy is present.
13. What is the phenotype when there are two recessive alleles?
    • A recessive allele is only expressed if two copies are present (therefore no dominant allele present).
14. What is the difference between homozygous and hetrozygous alleles?
    • If the two alleles present are the same the organism is homozygous for that trait, but if the alleles are different they are heterozygous.
15. Are most characteristics controlled by single genes or multiple genes interacting?
    • Multiple genes interacting
16. What is the probability of a child having homozygous recessive alleles if their parents are both hetrozygous for a trait?
    • 1:4 / 25%
17. What is the probability of a child having hetrozygous alleles if their parents are both hetrozygous for a trait?
    • 2:4 / 50%
18. What is the probability of a child having a diseases that is carried on a dominant alleles if their parents are both hetrozygous for a trait?
    • 3:4 / 75%
19. What is the probability of a child having homozygous dominant alleles if their parents are both hetrozygous for a trait?
    • 1:4 / 25%