1. Table of Contents Human Inheritance Human Genetic Disorders
Advances in Genetics

2. Patterns of Human Inheritance
Single genes with two alleles
Ex: widow’s pick
Figure 2 Punnett Square

3. Patterns of Human Inheritance
Single genes with multiple alleles
Ex: Inheritance of Blood Type
Blood type is determined by a single gene with three alleles.fig3/146

4. Patterns of Human Inheritance
Traits controlled by many genes
Ex: human height
Discovery activity/p144

5. The Sex Chromosomes - Human Inheritance
The sex chromosomes carry genes that determine whether a person is male or female. They also carry genes that determine other traits.

6. The Sex chromosomes Sex-linked genes- genes on the X and Y chromosomes
not always the same
Can have dominant and recessive alleles
Because males have only one X chromosome, male are more likely to have a sex linked trait that is controlled by recessive alleles.
Female -2X
Male 1X, 1Y

7. Colorblindness Punnett Square
- Human Inheritance
Colorblindness Punnett Square
Red-green colorblindness is a sex-linked trait. A girl who receives only one recessive allele (written Xc) for red-green colorblindness will not have the trait. However, a boy who receives one recessive allele will be colorblind.

8. Identifying Main Ideas
- Human Inheritance
Identifying Main Ideas
As you read the section “Patterns of Human Inheritance,” write the main idea in a graphic organizer. Then write three supporting details that further explain the main idea.
Main Idea
Human traits are controlled by single genes with two alleles, single genes with multiple alleles, and multiple genes.
Detail
Detail
Detail
Human traits controlled by single genes with two alleles have two distinctly different phenotypes.
Though a single gene can have multiple alleles, a person can carry only two of these alleles.
Multiple genes that control a trait act together to produce a single trait with a large number of phenotypes.

9. The effect of environment
Many of a person’s characteristics are determined by an interaction between genes and the environment

10. Click the SciLinks button for links on genetics.
- Human Inheritance
Links on Genetics
Click the SciLinks button for links on genetics.

11. End of Section: Human Inheritance

12. Human Genetic Disorders
Genetic disorder- abnormal condition that a person inherits through genes or chromosomes
Causes:
Mutations in the DNA of genes
Changes in the structure of chromosoms
Changes in the number of chromosomes

13. Human Genetic Disorders
Cystic Fibrosis- body produces abnormally thick mucus in the lungs or intestines
Cause by a recessive allele on one chromosome as a result of a mutation in which three bases are removed from a DNA molecule

14. Human Genetic Disorders
Sickle –Cell Disease
Affects hemoglobin, a protein in the red blood cells that carries oxygen; cells clog blood vessels
The allele is codominant with normal allele
A person with two sickle cell alleles will have the disease

15. Human Genetic Disorders
Hemophilia
Person’s blood clots very slowly or nor at all
Caused by a recessive allele on the X chromosome
Sex-linked disorder/occurs more in male than in females

16. Human Genetic Disorders
Down Syndrome
A person’s cell have an extra copy of chromosome 21 ( 3 chromosomes)
Occurs when chromosomes fail to separate properly during meiosis
Effect: some degree of mental retardation; heart defects

17. A Pedigree - Human Genetic Disorders
A pedigree is a chart or “family tree” that tracks which members of a family have a particular trait.

18. A Hemophilia Pedigree - Human Genetic Disorders
The pedigree shows the inheritance of hemophilia, a sex-linked disorder in a family.

19. Managing Genetic Disorders
Karyotypes- picture of all the chromosomes in a cell
Genetic counseling- understand the chances of having a child with a particular genetic disorder
Dealing with genetic disorders

20. Pedigree Activity - Human Genetic Disorders
Click the Active Art button to open a browser window and access Active Art about pedigrees.

21. Comparing and Contrasting
- Human Genetic Disorders
Comparing and Contrasting
As you read, compare and contrast the types of genetic disorders by completing a table like the one below.
Disorder
Description
Cause
Cystic fibrosis
Body produces abnormally thick mucus.
Recessive allele due to removal of three DNA bases
Sickle-cell disease
Red blood cells are sickle-shaped and have reduced ability to hold oxygen.
Codominant allele
Hemophilia
Blood clots slowly or not at all.
Recessive allele on X chromosome
Down Syndrome
Mental retardation and heart defects
An extra copy of chromosome 21

22. Click the Video button to watch a movie about sickle-cell disease.
- Human Genetic Disorders
Sickle-Cell Disease
Click the Video button to watch a movie about sickle-cell disease.

23. End of Section: Human Genetic Disorders

24. Advances in Genetics
Selective Breeding: selecting organisms with desired traits to be parents of the next generation
Inbreeding: crossing two individuals that have the similar
Characteristics
Hybridization: crossing two genetically different individuals;
the offspring will have the best traits from both parents

25. Changing Rice Production
- Advances in Genetics
Changing Rice Production
The graph shows how worldwide rice production changed between 1965 and New, hybrid varieties of rice plants are one factor that has affected the amount of rice produced.

26. Changing Rice Production
- Advances in Genetics
Changing Rice Production
Reading Graphs:
According to the graph, how did rice production change between 1965 and 2000?
Rice production increased.

27. Changing Rice Production
- Advances in Genetics
Changing Rice Production
Reading Graphs:
How many metric tons of rice per hectare were produced in 1965? How many were produced in 2000?
2 in 1965; 4 in 2000

28. Changing Rice Production
- Advances in Genetics
Changing Rice Production
Calculating:
Calculate the approximate difference between rice production in 1965 and 2000.
2 metric tons/hectare

29. Changing Rice Production
- Advances in Genetics
Changing Rice Production
Developing Hypotheses:
What factors besides new varieties of plants might help account for the difference in rice production between 1965 and 2000?
Possible answer: fertilizers and improved harvesting methods

30. Cloning
Organism that have the exact genes as the organism from which it was produced
Is cloning ethical?

31. Genetic Engineering - Advances in Genetics
Scientists use genetic engineering to create bacterial cells that produce important human proteins such as insulin.

32. Asking Questions - Advances in Genetics
Before you read, preview the red headings. In a graphic organizer like the one below, ask a question for each heading. As you read, write answers to your questions.
Questions
Answers
What is selective breeding?
Selective breeding is the process of selecting organisms with desired traits to be parents of the next generation.
Why are organisms cloned?
To produce offspring with desired traits
What is genetic engineering?
A process in which genes from one organism are transferred into the DNA of another organism
What advance has helped us learn about human genetics?
The Human Genome Project

33. Links on Genetic Engineering
- Advances in Genetics
Links on Genetic Engineering
Click the SciLinks button for links on genetic engineering.

34. Click the Video button to watch a movie about selective breeding.
- Advances in Genetics
Selective Breeding
Click the Video button to watch a movie about selective breeding.

35. End of Section: Advances in Genetics

36. Graphic Organizer Human traits controlled by such as Multiple alleles
Sex-linked genes
Single genes
Many genes
Widow's peak
Blood type
Height
Colorblindness

37. End of Section: Graphic Organizer