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

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

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

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

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

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

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

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.

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?

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?

Genetic Disorders Hypertrichosis