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

2. Inheritance of Blood Type
- Human Inheritance
Inheritance of Blood Type
Blood type is determined by a single gene with three alleles. This chart shows which combinations of alleles result in each blood type.

3. 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.

4. 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.

5. 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.

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

7. End of Section: Human Inheritance

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

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

10. 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

11. End of Section: Human Genetic Disorders

12. 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.

13. 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.

14. 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

15. 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

16. 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

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

18. 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

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

20. End of Section: Advances in Genetics

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

22. End of Section: Graphic Organizer