1. End Show Slide 1 of 43 Copyright Pearson Prentice Hall 14–1 Human Heredity 14-1 Human Heredity

2. End Show 14–1 Human Heredity Slide 2 of 43 Copyright Pearson Prentice Hall Human Chromosomes Karyotype Visual display of an individual’s chromosomes, which are paired and numbered.

3. End Show 14–1 Human Heredity Slide 3 of 43 Copyright Pearson Prentice Hall Human Chromosomes Human Karyotype: is this a male or female?

4. End Show 14–1 Human Heredity Slide 4 of 43 Copyright Pearson Prentice Hall Human Chromosomes Human and other mammals have two types of chromosomes: 1.Autosomes- Any chromosome other than a sex chromosome. 2.Sex Chromosomes- The X and Y chromosomes which determine gender. XX= Female XY= Male

5. End Show 14–1 Human Heredity Slide 5 of 43 Copyright Pearson Prentice Hall Human Genes Let’s talk about Human Blood Types Example of multiple alleles. Possible phenotypes for human blood types are: A, B, AB, and O. There are only 3 alleles for blood types in humans: A, B, and O. A & B are codominant.

6. End Show 14–1 Human Heredity Slide 6 of 43 Copyright Pearson Prentice Hall Human Genes The alleles for human blood type are written as: I A, I B, and i. Alleles I A and I B are co-dominant but both are dominant over i. i is recessive.

7. End Show 14–1 Human Heredity Slide 7 of 43 Copyright Pearson Prentice Hall Human Genes People with the genotype I A I B have type AB blood Genotype ii produce blood type O Genotypes I A I A or I A i produce blood type A Genotypes I B I B or I B i produce blood type B

8. End Show 14–1 Human Heredity Slide 8 of 43 Copyright Pearson Prentice Hall 1 child = AB 1 child = A 2 children = B

9. End Show Slide 9 of 43 Inherited Diseases A disease that is transmitted in the genes an organism inherits from its parents. Many result from mutations Many are carried on the autosomes and sex chromosomes. Copyright Pearson Prentice Hall

10. End Show Slide 10 of 43 Copyright Pearson Prentice Hall Inherited Autosomal Diseases Cystic Fibrosis Huntington Disease Sickle Cell Disease

11. End Show Slide 11 of 43 Copyright Pearson Prentice Hall Cystic Fibrosis: Affects glands of the body that secrete sweat and mucus. Affects the lungs Breathing is difficult Can affect other organs within your body Autosomal recessive disease (caused by a recessive trait that is carried on an autosome)

12. End Show Slide 12 of 43 Copyright Pearson Prentice Hall Huntington Disease: Degenerative disease of the nervous system Progressive (worsens with time) Breaks down nerve cells in brain Causes uncontrollable movements Mental Deterioration Premature Death Autosomal dominant disease (you only have to inherit one gene for the disease to develop) A child with a parent of Huntington disease has a 50% chance of inheriting the disease.

13. End Show Slide 13 of 43 Copyright Pearson Prentice Hall Sickle Cell Disease: AKA sickle cell anemia Changes a person’s hemoglobin Red blood cells fold or become distorted in shape The shapes cause blockages within blood vessels Weakness and pain are caused Damages brain, heart, and spleen Can be fatal Autosomal recessive disease More common in African Americans

14. End Show 14–1 Human Heredity Slide 14 of 43 Copyright Pearson Prentice Hall Human Genes Inherited Sex Chromosome Diseases Some traits other than gender are “sex linked traits,” meaning they are determined by alleles located on the sex chromosomes. Most sex linked traits are recessive Carried on the X chromosome

15. End Show 14–1 Human Heredity Slide 15 of 43 Because males have only 1 X chromosome, a male who carries the recessive allele will show the sex-linked recessive trait. Females have 2 X chromosomes, so a female must inherit two recessive alleles for the recessive trait to be expressed. Copyright Pearson Prentice Hall

16. End Show 14–1 Human Heredity Slide 16 of 43 Copyright Pearson Prentice Hall Sex linked genetic disorders Albinism: Albinism is a defect of melanin production that results in little or no color (pigment) in the skin, hair, and eyes Hemophilia: Body is unable to produce a protein that is needed for normal blood clotting. Bruise easily. Cannot stop bleeding. Usually males Color Blindness: The inability to see certain colors in the usual way. Muscular Dystrophy: Is a group of inherited disorders that involve muscle weakness and loss of muscle tissue, which get worse over time.

17. End Show 14–1 Human Heredity Slide 17 of 43 Genetics and the Environment Note that when it comes to disease, genetics is not always all or nothing. Copyright Pearson Prentice Hall

18. End Show 14–1 Human Heredity Slide 18 of 43 Copyright Pearson Prentice Hall

19. End Show 14–1 Human Heredity Slide 19 of 43 Copyright Pearson Prentice Hall

20. End Show 14–1 Human Heredity Slide 20 of 43 Copyright Pearson Prentice Hall Human Traits So to determine if something is inherited or not, we use a Pedigree. A pedigree is a chart, or family tree, that traces the inheritance of a trait.

21. End Show 14–1 Human Heredity Slide 21 of 43 Copyright Pearson Prentice Hall Human Traits Pedigree Charts A person who has at least one copy of an allele is called a carrier whether or not they actually have the trait.

22. End Show 14–1 Human Heredity Slide 22 of 43 Copyright Pearson Prentice Hall Human Traits A circle represents a female. A horizontal line connecting a male and a female represents a marriage. A shaded circle or square indicates that a person expresses the trait. A square represents a male. A vertical line and a bracket connect the parents to their children. A circle or square that is not shaded indicates that a person does not express the trait.

23. End Show 14–1 Human Heredity Slide 23 of 43 Copyright Pearson Prentice Hall Human Genes Pedigree Charts can determine: Harmful or unharmful diseases Human blood types Any type of trait