5.2

 Differences or variation in DNA are what makes us different from each other!  Each human cell contains 46 chromosomes  Each cell has 3 billion base pairs of DNA (wow!)  Our DNA is 99.99% similar  Of the 6 billion base pairs of DNA, only 5% are in the genes that code for RNA and proteins.

 Errors can occur when DNA is copied  UV light, X-rays, chemicals, etc. affect DNA

 Substitution – Exchanges one base for another.  CTGGAG----  CTGGGG  Insertion – Extra base pairs are inserted.  CTGGAG----  CTGGTGGAG

 Deletion- Section is lost, or deleted.  CTGGAG  CTAG  Frameshift- Message is no longer read correctly.  THE FAT CAT SAT ---  HEF ATC ATS AT

 Cells have different ways to repair mistakes  Certain enzymes can proofread DNA such as correcting mismatched base pairs

1. The mutation causes no effect. 1. Amino acids have more than 1 code 2. Enough protein may be produced already 2. The effect of a mutation is minor. 1. Could affect skin/eye/hair pigmentation 3. The effect of a mutation is great. 1. Genetic disorder/disease

 Sometimes passed from parents to offspring  Sickle Cell Anemia  Cystic Fibrosis (CF)  Hemophilia  Tay- Sachs Disease  Huntington’s Disease (HD)  Hypercholesterolemia  Cancer

 People can carry a tendency for a disease.  Alzheimer's  Emphysema  Diabetes  Cancer  Their behavior can prevent it:  Not smoking can prevent emphysema and many types of cancer

 Most genetic disorders cannot be cured, although progress is being made.  Families who have a history of genetic disorders are recommended to undergo counseling before having a child. They can find out how it could affect their offspring.  Some genetic disorders can be treated if diagnosed early enough, such as PKU (lacking a certain enzyme).  If known, that child can be put on a certain diet and medicine routine.

 Mutation occurs on gene that codes for hemoglobin  Hemoglobin – a protein that carries oxygen in red blood cells  Mutation causes 1 amino acid to be replaced with another

 Need 2 recessive genes to be affected (ss)  Can be a carrier (Ss)

5.3

 Random changes in DNA can introduce new traits in an organism  Humans can breed animals to get the certain traits they want.  Ex: a cow that gives more quantities of milk

The process of selecting and breeding parent organisms to pass on particular traits to the offspring. Bloodhound – strong sense of smell

 A sequence of DNA from an organism is first isolated, then inserted into the DNA of another organism.  The DNA inserted usually codes for a particular trait of interest  GMO – Genetically modified organism

 Can make plants more insect resistant.  Create crops suitable for areas with poor soil conditions

PROSCONS  Food can be resistant to certain bacteria and pests.  Reduces chemical pesticides  Increases food production  Add nutrients  Possibly harmful to the human body but still unknown  Could risk wild population like salmon

 Can be used to produce new and better drugs for treating disease  Determine the side effects of a drug on an individual  Can be used to screen for and treat genetic disorders

 May soon allow scientists to correct certain recessive genetic disorders by replacing defective genes with copies of a healthy one.  First step of gene therapy is to isolate a copy of the gene.  Scientists are trying to input that gene into the cell by attaching it to a cold virus. Attempts in humans have not been successful.  However, the outlook is promising.

 Crime scenes – skin, hair, blood  DNA profile – a DNA fingerprint  Everyone different except identical twins!

 All the genetic material in an organism.  The human genome project wanted to sequence all of the human genome (that’s a lot)  We can then compare DNA across species  We have similar genes to fruit flies and mice

 A technique that uses technology to make copies.  Can be applied to a segment of DNA or a whole organism Dolly 

 Place gene that codes for producing insulin  That bacteria then replicates in large numbers  Treats people with diabetes