1. What are dominant and recessive alleles?
………………… allele controls traits/ features that only show when there is no dominant allele in your genotype
……………….. allele takes over control of a feature whenever it is in your genotype
T = dominant (curly)
t = recessive (straight)
What do these reebops alleles code for?
A a B b L l H h

2. Learning objectives today…..
Can we predict phenotype from genotype?
What is a “genetic diagram”?
What is polydactyly and how is it inherited?
What is CF and how is it inherited?
What is embryo screening and is it right?
What are stem cells and is it right to use them?

3. Allele
Codes for
Dominant or recessive? A a B b L H h

4. What is Jack & Sal’s genotype?
Ann
Ken
Fifi
Sal
Jack
Jade
What is Ken’s genotype?
What is Jack & Sal’s genotype?
Who has Jack inherited his genotype from?
What is Ann’s genotype? You have enough information to be certain
What is Fifi’s genotype (you have enough information to be certain)
Ann is pregnant. What is the chance that her next child will be a boy?
Jack meets Jade. What is the chance they will have a curly tailed child?

5. What is Ken’s genotype?
What is Jack & Sal’s genotype?
Who has Jack inherited his genotype from?
What is Ann’s genotype? You have enough information to be certain
What is Fifi’s genotype (you have enough information to be certain)
Ann is pregnant. What is the chance that her next child will be a boy?
Jack meets Jade. What is the chance they will have a curly tailed child?

6. How can we predict what traits our kids might get?
Mum’s genotype
Dad’s genotype
Possible genotypes of kids

7. Remember… Some genes have more than one version
Different versions of a gene are called “alleles”
Genotype
Phenotype

8. Remember… Some genes have more than one version
Different versions of a gene are called “alleles”
Genotype
Phenotype

9. ? ? x Predict the chances of the couple having A blue eyed child
A brown eyed child ? ? ?

10. ? ? John Hannah x ? What is Hannah’s phenotype? (1 mark)
What is the chance of Pete having blue eyes?
(3 marks)
What is the chance of Pete having Brown eyes?
How could Pete have blue eyes when neither of his parents do? (2 marks) ? ? ?
Pete

11. Polydactyly
Condition caused by a dominant allele

12. Mum’s genotype d
Dad’s genotype D

13. Cystic Fibrosis A disease of the cell membrane
Caused by a recessive allele
Can 2 “healthy” parents have a kid with CF?

14. Screening for genetic disorders
This clip helps summarise the techniques used to screen for genetic disorders
Some words to help you!
Fertilised egg / zygote
Blastomeres
DNA
Genetic disorders.

15. Advantages Disadvantages
What are the advantages and disadvantages (social, economic and ethical) of embryo screening?
Advantages
Disadvantages
Economic
Social
Ethical
Jan 10 BLY2H Q5

16. Can stem cells really cure disease?
What is a stem cell?
Where do stem cells come from?
What are stem cells used for?
Is it right to use stem cells in research and medical treatments?

17. Zygote grows
as cells divide
by Mitosis
In the early growth stages the embryo cells are unspecialised stem cells

18. What is a stem cell? An “unprogrammed” cell that can develop into
……………….. other type of cell.
In the “right” conditions this cell could become a muscle cell
In other conditions this cell could instead become a bone cell

19. Where do stem cells come from? What are stem cells used for?
The best source of stem cells is …………………………………………………………
Human stem cells can also be found in adult’s ………………….. …………..
Stem cells can be programmed to develop (differentiate) into …………….type of cell.
Stem cells could be programmed to become nerve cells and used to treat ……………………………………
Anthony Atala
LZ Clip discussing use of stem cells and ethics surrounding their use