What is Genetics


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Brief description of Genetics

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What is Genetics

  1. 1. What is "Genetics"? The Study of Heredity
  2. 2. What is &quot;Genetics&quot;? <ul><li>Every living thing is made of cells (AKA the building blocks of life). </li></ul>
  3. 3. Plant Cell What is &quot;Genetics&quot;?
  4. 4. What is &quot;Genetics&quot;? Cork Cells Onion Cells
  5. 5. Animal Cell What is &quot;Genetics&quot;?
  6. 6. What is &quot;Genetics&quot;? Human Cheek Cell Frog Blood Cells
  7. 7. Interesting Information About Cells… In a normal adult male, a small drop of blood contains approximately 5,000,000 cells. A drop of blood from an adult female contains about 500,000 fewer cells. What is &quot;Genetics&quot;?
  8. 8. AIDS Cell What is &quot;Genetics&quot;?
  9. 9. Salmonella Bacteria Cells What is &quot;Genetics&quot;?
  10. 10. Strepto- coccus pneumonia bacteria cells What is &quot;Genetics&quot;?
  11. 11. Herpes Virus Cell What is &quot;Genetics&quot;?
  12. 12. Influenza Virus Cells What is &quot;Genetics&quot;?
  13. 13. Ebola Virus Cells What is &quot;Genetics&quot;?
  14. 14. Interesting Information About Cells… The average human has about one hundred trillion cells! What is &quot;Genetics&quot;?
  15. 15. 2. Most cells have large circular shaped structures inside, which are called the nucleus . This is the “brain” of the cell – controlling everything about the cell. What is &quot;Genetics&quot;?
  16. 16. 3. Inside the nucleus are the chromosomes, which are composed of DNA , which stands for deoxyribonucleic acid. These are the instructions for absolutely everything that goes on within the organism. What is &quot;Genetics&quot;?
  17. 17. What is &quot;Genetics&quot;?
  18. 18. Random Fact… If you took all the DNA from each of the cells in your body and stretched it out end to end, it would be long enough to reach from the earth to the sun and back! What is &quot;Genetics&quot;?
  19. 19. 4. Each of your cells contains about 25,000 sets of instructions. What is &quot;Genetics&quot;?
  20. 20. <ul><li>DNA is made of four chemicals: </li></ul><ul><li>A (adenine), T (thymine), </li></ul><ul><li>G (guanine), C (cytosine). </li></ul><ul><li>Continued… </li></ul>What is &quot;Genetics&quot;?
  21. 21. <ul><li>Continued… What accounts for differences in organisms is the order of these four chemicals within the DNA. </li></ul>What is &quot;Genetics&quot;?
  22. 22. <ul><li>Continued… In fact, there is just .2% difference between you and another person on earth - that means that every person has 99.8% of the exact same genetic information! </li></ul>What is &quot;Genetics&quot;?
  23. 23. <ul><li>How alike are other organisms to humans? </li></ul><ul><li>99% chimpanzees </li></ul><ul><li>88% mice </li></ul><ul><li>60% chickens </li></ul><ul><li>60% fruit flies </li></ul>What is &quot;Genetics&quot;?
  24. 24. 7. Gregor Mendel discovered much of what we know today about genetics through his work with pea plants. What is &quot;Genetics&quot;?
  25. 25. a. When crossing two pure tall pea plants, he found the results to be: all tall plants What is &quot;Genetics&quot;?
  26. 26. b. When he crossed two pure short plants, he got: all short pea plants What is &quot;Genetics&quot;?
  27. 27. <ul><li>Then he got a bit crazy… He crossed one tall and one short pea plant and got: all tall pea plants </li></ul>What is &quot;Genetics&quot;?
  28. 28. d. Then he took the “babies” (offspring from letter c) and crossed them, and he got: 75% tall plants and 25% short pea plants What is &quot;Genetics&quot;?
  29. 29. Interesting Information About Cells… The first cells weren’t seen until 1673, by a Dutch scientist named Anton van Leeuwenhoek. He scraped plaque off his teeth and looked at it under a simple microscope that he built himself. What is &quot;Genetics&quot;?
  30. 30. 8. From his experiments, Mendel found that there are certain basics to genetics that we now call their foundation: What is &quot;Genetics&quot;?
  31. 31. Inheritance <ul><li>Trait – the characteristics passed from parent to offspring </li></ul><ul><li>Genes : carry the traits, located on chromosomes </li></ul><ul><li>Allele : different forms of a gene </li></ul><ul><ul><li>Definition: An different form of a gene (one member of a pair) that is located at a specific position on a specific chromosome. For example, the gene for seed shape in pea plants exists in two forms, one form or allele for round seed shape (R) and the other for wrinkled seed shape (r). </li></ul></ul>What is &quot;Genetics&quot;?
  32. 32. a. Traits are passed down from one generation to the next generation . What is &quot;Genetics&quot;?
  33. 33. b. Traits are controlled by genes, which are found on chromosomes within the nucleus of cells in organisms. What is &quot;Genetics&quot;? So the order is Cells: nucleus:: chromosomes::: genes:::: DNA
  34. 34. <ul><li>Organisms inherit genes in pairs, one comes from each parent . </li></ul><ul><li>Hybrid – an organism that receives different genetic information for a trait from each parent </li></ul>What is &quot;Genetics&quot;?
  35. 35. Traits <ul><li>Not all traits are inherited through genes </li></ul><ul><ul><li>Some things are learned from our parents </li></ul></ul><ul><ul><ul><li>Table manners </li></ul></ul></ul><ul><ul><ul><li>Conduct in public and private </li></ul></ul></ul><ul><ul><ul><li>Responsibilities </li></ul></ul></ul><ul><ul><ul><li>Respect for authority </li></ul></ul></ul><ul><ul><ul><li>In other words: Conduct, Character and Conversation (Three C’s) </li></ul></ul></ul>What is &quot;Genetics&quot;? Very important to know the difference!!!!
  36. 36. Typing <ul><li>Phenotype – the form of the trait that is expressed in the physical characteristics of an organism (ex. Blue eyes, black fur) </li></ul><ul><li>Genotype – the genetic makeup of the genes. (ex. AA, Bb, cc) </li></ul>What is &quot;Genetics&quot;?
  37. 37. <ul><li>Some genes are dominant (stronger), and some are recessive </li></ul><ul><li>Dominant Trait – the trait that is expressed (appears) </li></ul><ul><li>Recessive Trait – the trait that is NOT expressed (does NOT appear) </li></ul><ul><ul><li>Homozygous = AA or aa </li></ul></ul><ul><ul><li>Heterozygous = Aa </li></ul></ul>What is &quot;Genetics&quot;?
  38. 38. e. Dominant genes mask recessive ones when one of each is inherited. What is &quot;Genetics&quot;?
  39. 39. f. Some traits don’t appear as dominant or recessive, but they appear as a mixture. This is called incomplete dominance . What is &quot;Genetics&quot;?
  40. 40. Random Fact… Eye color appears to be a trait that exhibits incomplete dominance, but its not really... There are at least two (if not more) genes that control eye color. That’s why there are so many shades of eye color in humans. Other traits that work this way include hair and skin color. What is &quot;Genetics&quot;?
  41. 41. 9. Identical twins are the only people that have the exact same DNA. What is &quot;Genetics&quot;?
  42. 42. What about twins? <ul><li>  I dentical twins , formed when one fertilized egg splits, are the only people in the world with identical DNA mostly with only small mutations (and not mitochondrial DNA). </li></ul><ul><li>  Fraternal twins , on the other hand, are formed when two different eggs are fertilized. Genetically speaking, fraternal twins are no closer than normal siblings, sharing only about 50% of their genes. </li></ul><ul><li>Although identical twins have the same  genotype , or DNA, they have different phenotypes , meaning that the same DNA is expressed in different ways. </li></ul><ul><li>Traits determined by  phenotype , such as fingerprints and physical appearance, are the result of &quot;the interaction of the individual’s genes and the developmental environment in the uterus.&quot; Thus, a DNA test can't determine the difference between identical twins, while a simple fingerprint can. </li></ul>
  43. 43. I knew you would ask… <ul><li>People with two types of DNA are called chimeras after a mythical creature with a lion's head, a goat's body, and a serpent's tail. These people have two different sets of DNA in different parts of the body.  How does someone become a chimera? There are a number of ways this can happen: First, it is possible to become a chimera if developing fraternal twin embryos fuse together to become one embryo. (Think of this is as the reverse of identical twins where a single embryo splits into two.) This happens very early on when the embryos are just unspecialized cells, so a healthy baby can still be made. Fraternal twins do not have the same DNA, so a mixture of two embryos will give a chimera. Second, chimeras can arise when developing fraternal twins share a blood supply. This happens when the twins (who have different DNA) share a placenta and cells from their blood mix. The twins will be chimeras only in terms of their blood since other cells in the body are not affected by the blood supply. Third, sometimes chimeras can happen through an error in the way cells divide in the developing embryo. Cells split into two to make more of themselves � something embryos need to do a lot of to grow into a baby. For this, cells need to double their DNA and divide it between the two new halves. Sometimes this goes wrong and some new cells end up with different DNA. If this happens early on, the tissues that come from these cells end up with a different genotype. </li></ul>Chimera
  44. 44. Crossing DNA
  45. 45. 10. Some people argue that there is more to you than just what is in your genes. They think you are also influenced by the environment in which you live . What is &quot;Genetics&quot;?
  46. 46. 11. Scientists have completed a map of the human genome , which means that they know the exact location of all of the genes on all 23 pair of chromosomes. What is &quot;Genetics&quot;?
  47. 47. 12. Continued… girls have two X chromosomes. This is the main difference between males and females, and it is determined by the father’s sperm cell. What is &quot;Genetics&quot;?
  48. 48. 12. You receive half of your genes from your mother (her egg) and half from your father (his sperm). If you are a boy, you have one X and one Y as your 23rd pair; What is &quot;Genetics&quot;?
  49. 49. Karyotype <ul><li>A photograph showing an individuals chromosomes </li></ul>What is &quot;Genetics&quot;?
  50. 50. Genetic Disorders <ul><li>Caused by mutations in genes </li></ul><ul><ul><li>MUTATION : a change or mistake in the genes </li></ul></ul>What is &quot;Genetics&quot;?
  51. 52. Punnett Square <ul><li>A grid used to organize genetic information </li></ul>What is &quot;Genetics&quot;?
  52. 53. Pedigree <ul><li>A chart that shows how a trait and the genes that control it are inherited in a family </li></ul>What is &quot;Genetics&quot;?