This lesson will increase your knowledge of concepts covered in the following TEKS for biology:

1. This lesson will increase your knowledge of concepts covered in the following TEKS for biology: 3.c – Evaluate impact of research on scientific thought, society, and the environment 3.f – Research and describe the history of biology and contribution of scientists. 4.a – Identify the parts of a cell 5.b – Identify cell differentiation in the development of organisms. 6.a – Describe components of DNA and illustrate how information for specifying the traits of an organism is carried in the DNA 6.b – Explain replication, transcription and translation using models of DNA and RNA

2. This lesson will increase your knowledge of concepts covered in the following TEKS for biology: 6.f – Identify and analyze karyotypes 10.a – Interpret the functions of systems in organisms 10.b – Compare the interrelationships of organ systems to each other and to the body as a whole

3. Previous LessonDNA and the Human Genome Project

4. Question: How many types of proteins are in a human and why do we need so many different types of proteins?

5. Each humans has about two million different types of proteins. • Proteins play a role in hair and muscles. They are essential to the immune system and most hormones and enzymes are proteins.

6. Question: Why would a plant cell have DNA in its nucleus and ribosomes in its cytoplasm? Based on Raven et al., Biology, McGraw HIll

7. Like animals, plants must produce proteins to regulate their biochemistry

8. Question: You are a unique person. What is the blueprint for life that makes you unique, and how does it act as a blueprint?

9. DNA is the Blueprint for Life Each person has a unique complement of DNA Each person to have a unique complement of protein Each person to have a unique appearance and behavior which causes which contributes to

10. Question: Why did many scientists think that sequencing the human genome was impossible? What made it possible?

11. The human genome consists of about 3 billion letters (nucleotide bases) • 15 billion dollars of federal funding made it possible

12. Today’s LessonIndividuality and Cloning

13. Overview of Lesson • Basics of genetics • Humans as unique individuals • Identical twins • Cloning of Dolly • Human cloning

14. Two Brothers Matt: Biology Fishing Hunting Bryan: Religion Philosophy Computers

15. Each human body cell has 23 pairs of homologous chromosomes (46 total) Half of the chromosomes are from the mother and half are from the father Karyotype

16. Each member of a homologous pair has the same genes but the alleles (specific expression of each gene) on each member might be the same or different Gene for hairline Widow’s peak allele Straight hair allele

17. Alleles are represented by letters Straight Hairline (w) is a recessive allele Widow’s Peak (W) is a dominant allele http://images.google.com/

18. Meiosis: formation of gametes in gonads Based on: Mader, S., Inquiry Into Life, McGraw-Hill

19. Meiosis results in: • gametes with half the number of • chromosomes as the number in our • body cells - 23 (n) instead of 46 (2n) • gametes with different chromosome • combinations

20. Overview of Lesson • Basics of genetics • Humans as unique individuals • Identical twins • Cloning of Dolly • Human cloning

21. Why are humans such unique individuals? …because each of us has a unique set of genetic instructions (set of alleles in DNA of chromosomes) due to the random assortment of chromosomes during generation of gametes (eggs and sperm) through meiosis

22. During meiosis in humans… …chromosomes can line up 223 or 10 million (107) different ways in meiosis I …so each person can produce 10 million (or 107) different types of gametes

23. For each couple… 107 types of sperm x 107 types of eggs 1014 types of children

24. Crossing-over between chromatids during meiosis makes it even more complex Based on: Mader, S., Inquiry Into Life, McGraw-Hill

25. The two brothers represent 2 out of more than 1014 possible children that a couple could conceive They are genetically programmed to be different

26. Overview of Lesson • Basics of genetics • Humans as unique individuals • Identical twins • Cloning of Dolly • Human cloning

27. Identical twins are produced when the two cell stage splits, forming two separate cells. Then the cells continue to divide separately forming two embryos. Two cell stage Based on: Mader, S., Inquiry Into Life, McGraw-Hill

28. Identical Twins Identical chromosomes (DNA) Identical proteins Very similar appearances

29. Identical Twins http://images.google.com/

30. Conjoined twins joined at the head Inner cell masses subdivide but do not separate completely, forming conjoined twins http://www.youtube.com/watch?v=BkKWApOAG2g

31. Overview of Lesson • Basics of genetics • Humans as unique individuals • Identical twins • Cloning of Dolly • Human cloning

32. What is cloning? Taking an adult (fully differentiated) cell, and restarting its genetic program and protein synthesis (as if it were a fertilized egg)

33. Why was cloning thought to be impossible? • as the genes of DNA regulate protein • synthesis during development, the • genes are turned off • (genes active at the zygote stage • are inactive in the adult) • to clone a mammal, the DNA would • have to be turned back on, as if being • read from the start (zygote stage)

34. Born in Scotland, Dolly was the first mammal to be cloned (1997) This showed that DNA in adult cells can be re-started In slide show mode, use the hot link below to download a copy of the cover of Time Magazine on Dolly TIME Magazine Cover: Dolly, Cloned Sheep - Mar. 10, 1997

35. Cloning of Dolly Based on: Raven, et al., Biology, McGraw-Hill

36. Cloning of Livestock • Sheep • Goats • Mice • Cows • Pigs U.S. News and World Report, March 27, 2000 U.S. News and World Report, December 21,1998

37. High Failure Rate in Animals • 2% success rate • Miscarriage frequent • Animals die after birth • Some animals have developmental • abnormalities • Death of offspring is 10 times • higher than normal before birth • and 3 times higher after birth

38. Overview of Lesson • Basics of genetics • Humans as unique individuals • Identical twins • Cloning of Dolly • Human cloning

39. Why would the U.S. House of Representatives vote in 2001 to ban human cloning?

40. Because of the unacceptable high risks of miscarriages and birth defects associated with cloning Furthermore, most Americans are opposed to human cloning

41. What would be the difference in a cloned child and its parental clone? What problems might this create for the cloned child?

42. A cloned child would be the genetically identical twin of the parental clone, but have a different personality (because personality emerges from nature and nurture) Parents might place unrealistic expectations An exception might be cloning a child who died at birth

43. What is the difference between therapeutic cloning and reproductive cloning of humans?

44. Therapeutic cloningcould be used to produce embryos with stem cells that could be used to treat diseases such as Parkinson’s Disease and diabetes. The cells would be a perfect genetic match for the person donating the cells. Reproductive cloningwill be used to produce embryos that will be implanted into a woman’s uterus and allowed to develop into an infant.

45. Next Lesson Genetic Disorders and Gene Therapy