Presentation on theme: "Cancer & Mutations Powerpoint"— Presentation transcript:
1Cancer & Mutations Powerpoint SB2. Students will analyze how biological traits are passed on to successive generations.d. Describe the relationships between changes in DNA and potential appearance of new traits includingAlterations during replication.InsertionsDeletionsSubstitutionsMutagenic factors that can alter DNA.High energy radiation (x-rays and ultraviolet)Chemical
2What is Cancer? Kinds of cancer Cancer - Uncontrolled cell growth *Cells only grow during the correct conditions*Limited by space, nutrients, chemicals, etc.Kinds of cancerCarcinomas – grow in the skin and he tissues that line the organs of the bodyEx. lung and breast cancerSarcomas – grow in bone and muscle tissueLymphomas – solid tumors that grow in the tissues that form blood cellsEx. leukemia, the uncontrolled production of white blood cells
3Tumor Tumor - mass of cell due to uncontrolled cell growth Benign - an abnormal, non-threatening cell massMalignant - uncontrolled cell mass that continually divides and multipliesMetastasis - spread of cancer cells beyond original site
4CancerCancer cells, unlike normal cells, continually grow even when the region is over crowded.The cell does not recognize the message to stop dividing.Normal cells will not go through cell division unless they are attached to neighboring cells.The cancer cells continue to grow and this leads to the spread of the problem throughout the body, also called metastasis.
5What causes cancer?Growth factors - proteins that ensure the events of the cell cycle progress in proper order.Ex Cyclins and CDKsMutations in these proteins result in uncontrolled cell growth.
6Cancer causesCarcinogens - any substance that increases the risk of cancerEx. Tobacco, asbestos, and radiation such as X-ray, and UV light from sun.
7Genes related to cancer Oncogenes – gene that causes cancer or other uncontrolled cell proliferationProto-Oncogenes – gene that codes for proteins involved in the cell cycleTumor-suppressor genes – code for proteins that prevent the uncontrolled rate of cell division
8Can Cancer Occur Organisms other than humans? DiscussionCan Cancer Occur Organisms other than humans?YesNo
9What is a mutation? Mutation – a change in the DNA of an organism Germ-line mutation – occur in gametes of organismPassed on to offspring, do not affect the organismSomatic mutation – mutations in the organism’s bodyAffect the organism, but not passed on to offspringEx. Skin cancer, leukemia, any cancer
10What causes mutations?Mutagens – agent that causes mutations to occur within a cell.Ex. Ionizing radiation, Base analogs, Intercalating agents, and Bromine
11Types of mutationsChromosome mutations – changes in the structure of a chromosome or loss of an entire chromosome.Deletion – loss of piece of DNA due to chromosomal breakageDuplication – Chromosomes steal part of homologs and have both alleles for each gene involvedInversion – piece of DNA breaks off and reattaches itself in opposite directionTranslocation – chromosome breaks off and reattaches to a non-homologous chromosomeNondisjunction – chromosome does not properly separate from its homolog during meiosis
13NondisjunctionResults in gametes receiving to many or too few chromosomesEx. Down Syndrome = trisomy of chromosome 21
14What kind of chromosomal mutation is this? Original chromosomeDuplicationTranslocationInversionDeletion
15What kind of chromosomal mutation is this? Original chromosomeDuplicationTranslocationInversionD. Deletion
16Gene MutationsMay involve a large section of DNA or a single nucleotide within a codonPoint mutation – the substitution or change of a single nucleotideInsertion or Deletion – one nucleotide is removed from or added to a sequenceFrame shift mutation – occurs when codons are incorrectly grouped
17Point Mutation Can result in No effect - the protein structure is not changedMissense – one amino acid is replaced by anotherNonsense – prematurely stop codon in amino acid sequence
18Point mutationEx. Sickle cell anemia –mutation in a single nucleotide that causes the malformation of the hemoglobin molecule which carries oxygen to our cells
19Insertion and Deletion The removal or addition of a nucleotide base to a sequence usually results in a frameshift mutation.
20Using the genetic code provided, which chain of amino acids corresponds to this mRNA sequence? UCAAUGGUCUGAGlu, Tyr, Met, ArgSer, Val, Arg, StopSer, Met, Val, StopVal, Iso, Asp, Stop
21What if the first G was changed to a C, what would the new amino acid chain be? UCAAUGGUCUGAGlu, Tyr, Met, ArgSer, Leu, Arg, StopVal, Ile, Ser, StopSer, Iso, Val, Stop
22What affect does this mutation have on the function of the protein? Proteins are folded in a specific fashion according to the amino acid sequence it contains.This would cause the function of the protein to be severely reduced or not functional at all.
23Mutations lead to Evolution Mutations are not always bad, they often provide variations on proteins and sometimes these are advantageous to us.Survival of the fittest and Natural selection.
24How can one tell the history of hereditary traits in his or her family? Pedigree – diagram of genetic history of an individual showing how traits are inherited over several generations
25Pedigrees Dominant disorders Recessive disorders Genetic disorders – diseases or debilitating conditions that have a genetic basisCarriers – individuals with one copy of a recessive autosomal allele; do not usually express the disorder but can pass on to offspring
26PolydactylyDominant trait that results in offspring with extra fingers or toes.
27HemophiliaA sex-linked, recessive genetic disorder that affects the individuals ability to clot blood.