1. Heredity

2. Objective 8 Describe the function of chromosomes. Describe the function of chromosomes. Identifying genes as parts of chromosomes that carry genetic traits. Identifying genes as parts of chromosomes that carry genetic traits.

3. In the past, traits were thought to be carried by the blood. In the past, traits were thought to be carried by the blood. We now know what genes are responsible for certain traits and that the genes are in every cell. We now know what genes are responsible for certain traits and that the genes are in every cell. We have used this information and completed the Human Genome project. The mapping out of the human DNA. We have used this information and completed the Human Genome project. The mapping out of the human DNA.

4. Pass it on Every organism requires a set of instruction for specifying its traits. Heredity is the passage of these instruction from one generation to another. Every organism requires a set of instruction for specifying its traits. Heredity is the passage of these instruction from one generation to another.

5. Heredity The passing of traits from parent to offspring. The passing of traits from parent to offspring.

6. Let’s consult with Tim and Moby. Let’s consult with Tim and Moby. Heredity film. Heredity film.

7. Heredity information is contained in genes, located in the chromosomes of each cell. Heredity information is contained in genes, located in the chromosomes of each cell. Each gene carries a single unit of information. Each gene carries a single unit of information.

8. Chromosomes They are composed of genes that provide the instruction for making all the proteins in an organism. They are composed of genes that provide the instruction for making all the proteins in an organism.

9. During cell division, the duplicated chromosomes separate so that one copy of each chromosomes is present in the two new cells. During cell division, the duplicated chromosomes separate so that one copy of each chromosomes is present in the two new cells.

10. This photomicrograph shows a specialized type of giant chromosomes called polytene chromosomes. Polytene chromosomes occur in many species of two-winged flies. This photomicrograph shows a specialized type of giant chromosomes called polytene chromosomes. Polytene chromosomes occur in many species of two-winged flies.

11. Homologous chromosomes Chromosomes that have the same sequence of genes and have the same structure. Chromosomes that have the same sequence of genes and have the same structure.

13. Down syndrome is often called Trisomy 21 because most people with this condition have three copies of the number 21 chromosome. Down syndrome almost always results in mental retardation, though the severity of the retardation varies. Down syndrome is often called Trisomy 21 because most people with this condition have three copies of the number 21 chromosome. Down syndrome almost always results in mental retardation, though the severity of the retardation varies.

14. Genes Segments of DNA that carry hereditary instructions and are passed from one parent to offspring; located on the chromosome. Segments of DNA that carry hereditary instructions and are passed from one parent to offspring; located on the chromosome.

16. Let’s watch Tim and Moby give information about Genes. Let’s watch Tim and Moby give information about Genes.

17. Alleles Different forms of a single gene or Alternate forms of a gene. Different forms of a single gene or Alternate forms of a gene.

18. Alleles example For example, a mother might pass on a gene for blue eyes to her offspring, and the father might pass on a gene for brown eyes. Each parent passes on one allele to the offspring. Each offspring has two alleles for each trait such as eye color. The expression of physical characteristics depends on the genes contributed by both parents for that particular characteristic. For example, a mother might pass on a gene for blue eyes to her offspring, and the father might pass on a gene for brown eyes. Each parent passes on one allele to the offspring. Each offspring has two alleles for each trait such as eye color. The expression of physical characteristics depends on the genes contributed by both parents for that particular characteristic.

20. An inherited trait of an individual can be determined by one or by many genes, and a singles gene can influence more than one trait. A human cell contains many thousands of different genes. An inherited trait of an individual can be determined by one or by many genes, and a singles gene can influence more than one trait. A human cell contains many thousands of different genes.

21. Traits inherited characteristic: a quality or characteristic that is genetically determined. inherited characteristic: a quality or characteristic that is genetically determined.

22. Dominant Trait The trait observed when at least one dominant allele for a characteristic is inherited. The trait observed when at least one dominant allele for a characteristic is inherited.

23. Recessive Trait A trait that is apparent only when two recessive alleles for the same characteristic are inherited. A trait that is apparent only when two recessive alleles for the same characteristic are inherited.

24. Albinism, the lack of normal pigmentation, occurs in all races. A rare condition, albinism occurs when a person inherits a recessive allele, or group of genes, for pigmentation from each parent. Albinism, the lack of normal pigmentation, occurs in all races. A rare condition, albinism occurs when a person inherits a recessive allele, or group of genes, for pigmentation from each parent.

25. Human Genome Project Completed in 2003, the Human Genome Project (HGP) was a 13-year project coordinated by the U.S. Department of Energy and the National Institutes of Health. Completed in 2003, the Human Genome Project (HGP) was a 13-year project coordinated by the U.S. Department of Energy and the National Institutes of Health.

26. Project goals were to goals identify all the approximately 20,000-25,000 genes in human DNA, identify all the approximately 20,000-25,000 genes in human DNA, determine the sequences of the 3 billion chemical base pairs that make up human DNA, determine the sequences of the 3 billion chemical base pairs that make up human DNA, store this information in databases, store this information in databases, improve tools for data analysis, improve tools for data analysis, transfer related technologies to the private sector, and transfer related technologies to the private sector, and address the ethical, legal, and social issues (ELSI) that may arise from the project. address the ethical, legal, and social issues (ELSI) that may arise from the project.

27. What are some practical benefits to learning about DNA? Knowledge about the effects of DNA variations among individuals can lead to revolutionary new ways to diagnose, treat, and someday prevent the thousands of disorders that affect us. Knowledge about the effects of DNA variations among individuals can lead to revolutionary new ways to diagnose, treat, and someday prevent the thousands of disorders that affect us.

28. The end