1. Chapter 9 DNA: The molecule of heredity What is heredity? What does DNA have to do with heredity? What is DNA? What is a chromosome? What is a gene? What is the relationship between chromosomes, DNA and genes? What is a genome? How is DNA inherited? Why is it important to know about DNA?

2. I.DNA - the "molecule of heredity" A. DNA—the genetic information of all living organisms B. Genetic information units are called genes 1.Gene—a length of DNA containing information to make a protein

3. What is heredity? The genetic transmission of characteristics from parent to offspring Parent cells to offspring cells Parent organisms to offspring organisms

4. What does DNA have to do with heredity? DNA encodes information which results in your characteristics Offspring (cells and organisms) receive DNA from their parents

5. What is DNA? Two polymers of nucleotides which interact via complementary base pairing

7. What is DNA?

8. 1953 – James Watson & Francis Crick model DNA structure as a double helix

9. What is a chromosome? Chromosomes contain DNA and associated proteins (which allow the DNA to condense/wind up tightly)

10. What is a chromosome? Tightly packed DNA wrapped around histone proteins

11. What is a chromosome?

12. What is a gene? A sequence of DNA nucleotides which encodes information for a cell to make a specific protein Example: CFTR geneCFTR gene

13. What is the relationship between chromosomes, DNA, and genes? genegenegene Chromosomes contain DNA Genes are sequences of DNA nucleotides Genes are located on chromosomes

14. What is a genome? All the DNA found in a species

15. The Human Genome 46 chromosomes (23 pairs) ~30,000 genes

16. Human Genome Project -Sequenced the human genome -Mapped all human genes GeneMap link GeneMap link Chromosome viewer Chromosome viewer

17. 1.DNA contains hundreds of chromosomes which are composed of genes. 2.A chromosome contains hundreds of genes which are composed of DNA. 3.A gene contains hundreds of chromosomes which are composed of DNA. 4.DNA contains hundreds of genes which are composed of chromosomes. What is the relationship among DNA, a gene, and a chromosome?

18. Which of the following represents proper complementary base pairing in DNA? 1)Adenine with guanine; cytosine with thymine 2)Thymine with thymine; cytosine with cytosine 3)Adenine with cytosine; guanine with thymine 4)Adenine with thymine; guanine with cytosine 5)None of the above

19. The DNA of an organism contains 20 percent cytosine nucleotides. What percentage of its bases would be guanine? 1)10 percent 2)20 percent 3)30 percent 4)40 percent 5)80 percent 6)It cannot be determined

20. How is DNA inherited? DNA is replicated (copied) prior to cell division Each cell “inherits” a copy of each replicated chromosome

21. DNA replication results in “double stranded” chromosomes

22. How is DNA inherited? DNA replication is followed by cell division

23. DNA replication is semi-conservative

24. DNA replication animationanimation

25. Why is knowledge of DNA important? DNA is involved in most, if not all characteristics DNA can change Changes in DNA can result in diseasedisease Understanding genes involved in disease can lead to prevention and treatment of disease

26. DNA polymerase and point mutations 1 mistake made every 10,000 replicated nucleotides

27. Repair enzymes limit mutations to 1 in a billion replicated nucleotides

28. Uncorrected replication errors may result in genetic disorders & diseases

33. Gene mutation & deafness

37. Obesity research in mice

39. Personal decisions can result in greater/lesser frequency of point mutations

40. Why are there mutations? For evolutionists: Since mutations result in serious disorders, why has evolution not perfected a DNA polymerase that does not make mistakes? For creationists: Since mutations result in serious disorders, why would an all knowing, loving God design us with an imperfect DNA polymerase that makes mistakes?

41. Mutations are a source of genetic diversity

42. Phenotypic variation (diversity) is based on genetic variation

43. Mutations are a source of genetic diversity

44. Genetic variation and community interactions

45. A length of DNA containing information to make a protein is called 1)a chromosome 2)An exon 3)A gene 4)DNA helicase 5)a nucleotide

46. Replication of the DNA sequence, GATTAC would produce the sequence 1)GATTAC 2)CATTAG 3)CTAATG 4)AGCCGA 5)None of these

47. 1.each new DNA molecule contains two new single DNA strands. 2.some mistakes are made during DNA replication. 3.certain nucleotides pair with other specific nucleotides. 4.Each DNA molecule produced consists of one parental DNA strand and one newly synthesized strand. 5.Only half the chromosomes are copied during replication. Semiconservative replication refers to the fact that

48. The enzyme that replicates DNA by catalyzing the dehydration synthesis of individual nucleotides is 1) DNA replicase 2) DNA synthetase 3) DNA polymerase 4) Nucleotidase 5) DNA helicase

49. A random change in a nucleotide of DNA 1)is always harmful to the organism 2)is always corrected by repair enzymes 3)will kill the organism in which it occurs 4)is never beneficial to the organism 5)can occur during DNA replication