1. Do now: Put these in order from which is the largest to the smallest:
Rātū, 25 Paenga-whāwhā, 2017
Do now:
Put these in order from which is the largest to the smallest:
gene
nucleus
chromosome
cell
DNA

2. Do now: Put these in order from which is the largest to the smallest:
Rātū, 25 Paenga-whāwhā, 2017
Do now:
Put these in order from which is the largest to the smallest:
cell
nucleus
chromosome
gene
DNA

3. Today’s Learning:
1) Explain what is meant by dominant and recessive 2) Explain what an allele is 2) Use a Punnett Square

4. What sex will your child be?
Female X X
Copy! X
Male XX XX Y XY XY
2/4 or 50% chance of a male or female

5. Tongue rolling
How many people in the class could roll their tongues?

6. Homozygous dominant and recessive
Roller gene (R) is dominant
Non-roller gene (r) is recessive
Female r R R Rr RR
Probabilities
Homozygous dominant and recessive
Heterozygous
Male r Rr
r r

7. b B B b Bb BB Bb bb Brown eyes (B) are dominant
Blue eyes are recessive (b)
Female b B B Bb BB
Male b Bb bb

8. An allele is just a type of gene e.g. B=Brown eyes, b = blue eyes
The allele which will always be expressed is called the Dominant allele.
The allele which may be hidden is called the Recessive allele.

9. In mice, pointed ears (E) are dominant over round ears (e)
Draw the Punnett square for offspring of a “pure-breed” male with pointed ears (EE) and a female with round ears (ee).
What is the probability the offspring has round ears?

10. In mice, pointed ears (E) are dominant over round ears (e)
Draw the Punnett square for offspring of a “cross-breed” male with pointed ears (Ee) and a female with round ears (ee).
What is the probability the offspring has round ears?

11. Genetic Disorders
Hypertrichosis