* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download UNIT 4 PART 2 APPLIED GENETICS
Epigenetics wikipedia , lookup
Human genome wikipedia , lookup
DNA profiling wikipedia , lookup
Mitochondrial DNA wikipedia , lookup
Zinc finger nuclease wikipedia , lookup
Comparative genomic hybridization wikipedia , lookup
DNA polymerase wikipedia , lookup
Oncogenomics wikipedia , lookup
Nutriepigenomics wikipedia , lookup
SNP genotyping wikipedia , lookup
Primary transcript wikipedia , lookup
Cancer epigenetics wikipedia , lookup
Bisulfite sequencing wikipedia , lookup
Genome (book) wikipedia , lookup
United Kingdom National DNA Database wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Frameshift mutation wikipedia , lookup
DNA damage theory of aging wikipedia , lookup
Genealogical DNA test wikipedia , lookup
Gel electrophoresis of nucleic acids wikipedia , lookup
DNA vaccination wikipedia , lookup
Epigenomics wikipedia , lookup
Nucleic acid double helix wikipedia , lookup
Genomic library wikipedia , lookup
Non-coding DNA wikipedia , lookup
Microsatellite wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
No-SCAR (Scarless Cas9 Assisted Recombineering) Genome Editing wikipedia , lookup
Genetic engineering wikipedia , lookup
DNA supercoil wikipedia , lookup
Molecular cloning wikipedia , lookup
Extrachromosomal DNA wikipedia , lookup
Designer baby wikipedia , lookup
Genome editing wikipedia , lookup
Cell-free fetal DNA wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
Helitron (biology) wikipedia , lookup
Deoxyribozyme wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Point mutation wikipedia , lookup
UNIT 4 PART 2: APPLIED GENETICS • Sexual reproduction brings about variation. • The offspring are genetically different from either parent. • Genetic variation allows a species to adapt to a changing environment. This can lead to evolution of the species. • Most variation is the result of segregation and crossing over during meiosis and recombination during fertilization. • Another way to get variations is through mutations. 1 MUTATIONS • A mutation is a sudden change in the genetic material. • Gene mutations occur randomly and can occur in any cell. • Mutations can happen accidentally or can be caused by radiation or toxic chemicals. • A mutation in a single body cell does not pose any real threat. • For a mutation to be inherited it must occur in a sex cell or gamete. • At the time of fertilization, the mutated gamete passes on the mutation to all the cells of the offspring. 2 CHROMOSOMAL MUTATIONS • A change in the structure of a chromosome. • Normal order of genes: ABCDEFG – Translocation – A piece from another chromosome attaches • ABCDEFGXYZ – Inversion – Part of chromosome is turned around • ABEDCFG – Addition – Adding on a piece from the homologue • ABCABCDEFG – Deletion – Part of chromosome is missing • ABCFG Missing a piece 3 NONDISJUNCTION • Nondisjunction – the addition or loss of a whole chromosome. It is caused when chromosomes fail to separate during meiosis. • Down, • Patau, • Turner, • Edward’s syndromes. 4 GENE MUTATIONS- POINT MUTATIONS • • The substitution of one nucleotide for another. ATG-CGT-TAA ATG-GGT-TAA – – changing one base might result in a defective protein Sickle Cell Anemia has a Valine instead of Glutamic Acid (Glutamate) 5 GENE MUTATIONS- FRAMESHIFT MUTATIONS When nucleotides are added or deleted all the codons beyond that point are changed. Example: • • ATCGCGGTAACA ATCGGTAACA….. THE DOG ATE THE CAT THE DOG GOT SIC THE GAT ETH ECA TTH EDO GGO TSI C 6 PEDIGREE CHART • A pedigree chart allows geneticist to trace a condition through a family and predict where it may occur in the future: – – – – – Squares = Males Circles = Females Filled = Has condition Empty = Normal Half = Carrier A typical X-linked recessive trait that is found mainly in males, but females are carriers, and often skips a generation. 7 GENETIC SCREENING • Some genetic disorders may be detected before birth. • Biochemical tests may be done to look for a chemical disorder such as PKU. • Ultrasound may be used to detect physical disorder. 8 PHENYLKETONURIA - PKU • PKU is caused by a defective gene on an autosome for an enzyme that breaks down phenylalanine. • Without the enzyme phenylalanine builds up and damages the baby’s brain. • A simple blood test can detect PKU & diet can control it. 9 KARYOTYPE • A karyotype can be used to detect chromosomal disorders caused by nondisjunction. • It is made by photographing the chromosomes from a human cell and arranging them in pairs. • A geneticist may then look for any abnormal pairs. 10 AMNIOCENTISIS • Testing of the amniotic fluid that surrounds the baby in the uterus is called amniocentesis. • It is performed between the 13th and 18th week of pregnancy. • The purpose of the test is to count and analyze the number of chromosomes present. 11 CHORIONIC VILLUS SAMPLING • Chorionic villus sampling (CVS) is a prenatal test that involves taking a sample of some of the placental tissue. • This tissue contains the same genetic material as the fetus and can be tested for chromosomal abnormalities and some other genetic problems. 12 Genetics can be used to produce organisms with desired traits. • Selective breeding – Individuals showing the desired traits are purposely chosen for mating. • Inbreeding – The mating of closely related individuals to obtain desired characteristics. – Used to produce purebred domestic animals. Foxes become dog-like with selective breeding. 13 GENETIC ENGINEERING We can identify and locate individual genes, which means genes can be Removed, put together, and recombined: 1. Cut out the desired DNA of the gene 2. Combine that DNA with that of the recipient 3. Insert it into the new organism 14 STEP ONE: ISOLATING DNA Restriction Enzymes • Restriction enzymes recognize specific sequences of DNA bases and split each DNA strand at a specific site within that sequence. • This one recognizes the base sequence "G-A-A T-T-C" and cuts each strand between the "G" and the "A" as shown by 15 the red arrow. STEP TWO: RECOMBINING DNA • • Pieces of DNA from one organism can be spliced (glued) into DNA of another organism using an enzyme. The recombinant DNA is then put into a new The recombinant cell follows organism. the instructions from the new DNA 16 STEP THREE: INSERTING THE DNA • Vectors (Carriers) • • carry pieces of DNA from one location to another Types of Vectors: • bacterial plasmids • • • small circular pieces of DNA they have the ability to replicate in another cell viruses • • DNA can be added to the virus’ DNA virus infects a host cell & inserts its DNA 17 Recombinant Genetics: Insulin • A bacterial plasmid (chromosome) is cut open with a restriction enzyme. • The same enzyme is used to cut out the human gene for insulin. • These cut pieces of DNA are put together and their “sticky” ends attach to each other. • The recombinant plasmid is now placed inside of a bacterium to produce insulin. 18 Gel Electrophoresis • Proteins and Nucleic Acids are separated by running them through an electrified gel. • Restriction Enzymes are used to cut the DNA into different size pieces. • The large pieces move slowly, while the small pieces move quickly. • This is sometimes called DNA 19 fingerprinting. PCR Polymerase Chain Reaction • The Polymerase Chain Reaction (PCR) can make billions of copies of DNA in a short time. • The DNA is doubled at each cycle and at the end of 32 cycles it has been amplified 1 billion times. • A cycle can be done in as little as 17 seconds, so it is possible to get a billion-fold amplification in less than an hour. 20 Use of PCR in Forensic Science 1. DNA Evidence is multiplied using PCR. 2. Then it is separated using gel electrophoresis. 21 Cloning • The nucleus is removed from an unfertilized egg. • The nucleus from a donor cell is transferred into the egg. • The diploid (2n) egg is then implanted into a foster mother to grow. • The lamb is identical to the donor. 22