1. Genetics

2. Human Chromosomes
karyotype – an image showing the chromosomes in an organism

3. Human Chromosomes mutation – a change in a chromosome
may be helpful, harmful, or have no noticeable effect

4. Human Chromosomes mutation may cause disease or disorder
melanoma (skin cancer) – a deletion in #9

5. Human Chromosomes
Down’s Syndrome – an extra copy of chromosome #21

6. Sex Determination
23rd pair of chromosomes causes an organism to be either male or female
two X chromosomes = female
An X and a Y chromosome = male
women always pass their offspring an X
men pass their offspring either an X or a Y
therefore, the father determines the sex of the offspring
even though these are whole chromosomes (long strands of DNA, thousands of genes), a Punnett square can be used to show these results

7. 23rd Pair of Chromosomes

8. Sex-linked Gene any gene found on the 23rd pair of chromosomes
X chromosome is dominant over Y chromosome
any disease or disorder carried on the X will appear in males
to appear in females, both X’s would have to have the disease or disorder
example = females who can see color can pass color-blindness to their sons.

9. Color-blindness is a Sex-linked Gene

10. Co-Dominance neither allele is strong enough to overcome the other
both alleles attempt to show up

11. Multiple Alleles more than two different forms of a gene
example = blood type
A = dominant
B = dominant
O = recessive
6 possible genotypes (letter combinations)
4 phenotypes (results)

12. Multiple Alleles

13. Polygenic Inheritance
one trait produced from many genes
several sections of DNA cause the result of a single trait
examples = shades of eye color, shades of hair color, fingerprints

14. Polygenic Inheritance

15. Pedigree
a chart that shows the genetic history of an entire family

16. Pedigree Analysis All pedigrees use common symbols.
Answer the following questions.
What does an empty square represent?
What does a shaded square represent?
What does a ½ shaded square represent?
What does shaded circle represent?
What does an empty circle represent?
What does a ½ shaded circle represent?

17. I = grandparents II = parents III = children

18. Pedigree Analysis
Based on the pedigree in the previous slide, answer the following questions.
In row I, how many males can roll their tongue?
In row I, how many females can roll their tongue?
In row II, how many males can roll their tongue?
In row II, how many females can roll their tongue?
In row III, how many males can roll their tongue?
In row III, how many females can roll their tongue?
How is a pedigree different from a Punnett square?
Why would it be useful or important to see several generations of characteristics at one time?

19. Selective Breeding mating organisms with desirable characteristics
pets (personality, ability, appearance)
produce (insect resistant, increased size and amount of fruits and vegetables)
livestock (more meat in cows and chickens; more eggs from chickens)

21. Genetic Engineering
actually changing/manipulating the DNA of organism inside the cell
new products = food, fabrics, medicines
example: insulin production by bacteria
the human gene that produces insulin has been identified
the human gene for insulin is isolated and inserted into a bacteria
the bacteria produces human insulin
the synthetic insulin is used to treat diabetes in humans