Download DNA, RNA, Genetic Engineering

DNA, RNA, Genetic Engineering
Genetics Review
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Humans have 46 chromosomes
Egg and sperm 23 chromosomes
Meiosis
1. Produces gametes
2. 4 sperm
3. 1 egg & 3 polar bodies
IPMATPMAT
1. 1 replication
2. 2 divisions
Crossovers
Male XY, Female XX (Y= Male)
DNA- Deoxyribonucleic Acid
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Bases = A, T, C, G
Sugar = Deoxyribose
# of Strands = 2 Strands (Double Helix)
RNA- Ribonucleic Acid
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3 types of RNA
1. mRNA= codon sequence matching DNA
2. rRNA= ribosomal
3. tRNA= transfer (carries anticodon & AA)
All RNA is copied from DNA
Bases = A, U, C, G
Sugar = Ribose
# of Strands = 1 Strand
Replication
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Takes place in Nucleus
Copes DNA to DNA
Semiconservative (one original and one new strand)
Copying done by DNA polymerase
Okazaki fragments
3’ to 5’ (leading v. lagging strand)
Mitosis and Meiosis
Transcription
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Takes place in nucleus
Copies gene from DNA to RNA
Copying done by RNA polymerase
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Exons kept and introns cut out
Final mRNA leaves through nuclear pore
Template strand is what mRNA copied from
Coding strand is same as mRNA but w/ T instead of U
Translation
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Takes place at ribosome
Codon (triplet) matches to anticodon on tRNA
tRNA brings AA to ribosome to build peptide chain
Start codon= Met (yes, codes for AA & can be inside sequence)
Stop codon= stop (no AA & terminates sequence)
Mutations
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Mutation effect
1. Beneficial – helps organism survival & reproduction
2. Harmful – hurts organism survival & reproduction
3. Silent (Neutral) – no impact on organism survival & reproduction
Point Mutations (substitution)
1. Missense – creates a new AA
2. Nonsense – creates a STOP codon
3. Silent (Neutral) – changes sequence, but still codes for same AA
Frame Shift
1. Deletion (shift bases left)
2. Insertion (duplication; shift bases right)
3. Localized (deletion and insertion; left or right depends on which is first)
Chromosomal mutations
1. Deletions - ABCDEF ACDEF
2. Insertions - ABCDEF ABBCDEF
3. Inversion - ABCDEF ABCFED
4. Translocation - ABCDEF GHIDEF
Chromosomal # mutations (Meiosis Problems)
1. Nondisjunction (Aneuploidy) extra or missing chromosomes
2. Polyploidy (extra sets of chromosomes)
• Works in plants (bigger, stronger, more flowers, etc.)
• Does NOT work in animals (lethal)
Genetic Engineering
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Selective Breeding
1. Inbreeding (i.e. dog breeds, horse breeds, etc.)
2. Hybridization (i.e. hybrid plants, labradoodle, mule, etc.)
3. Induced (forced) Mutations
Cloning (cell, DNA, organism)
1. Identical Twins
2. Plants & Bacteria
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3. Steps
1. A body cell is taken from a donor animal.
2. An egg cell is taken from a donor animal.
3. The nucleus is removed from the egg.
4. The body cell and egg are fused by electric shock.
5. The fused cell begins dividing, becoming an embryo.
6. The embryo is implanted into the uterus of a foster mother.
7. The embryo develops into a cloned animal.
Recombinant DNA technology
1. Plasmid (bacteria)
2. Restriction enzyme (very specified; found in your body)
3. Gel electrophoresis
• ID and separate fragments
• Smaller fragments travel faster and farther down the gel
4. Polymerase Chain Reaction (PCR; amplify DNA)
5. Cell transformation (from one organism to another)
• Bacteria making HGH
• Xenotransplantation (mouse with ear)
Gene Therapy (v. enhancement)
o Gene therapy – helps individual reach “normal” level
o Gene enhancement – improves individual beyond “normal” level
o Viruses and liposomes (Bone morrow and CF)