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AIR Biology Review. DNA & RNA, PROTEIN SYNTHESIS, HEREDITY & EVOLUTION. DNA Replication – making a copy of DNA. Why does a cell do it?. So the cell can reproduce. www.lewport.wnyric.org/jwanamaker/animations.htm. What is the complementary strand of the DNA shown?.
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AIR BiologyReview DNA & RNA, PROTEIN SYNTHESIS, HEREDITY & EVOLUTION
DNA Replication – making a copy of DNA Why does a cell do it? So the cell can reproduce • www.lewport.wnyric.org/jwanamaker/animations.htm
What is the complementary strand of the DNA shown? • A T T G C T A T C G A
Answer A T T G C T A T C G A T A A C G A T A G C T
DNARNAProtein How do we get from gene to protein? translation transcription
Transcription The process of transferring information from DNA to mRNA Occurs in nucleus
What RNA strand would be made from the DNA shown? • A T T G C T A T C G A G
Answer REMEMBER! RNA does NOT have thymine! U A A C G A U A G C U C A T T G C T A T C G A G mRNA: codon codon 3 codon 2
2. Translation– synthesizing a protein • Takes place in cytoplasm on ribosomes • Reads mRNA codons to put amino acids in order to make a protein
Genetic Mutations • Any change in the genetic code NOT ALL MUTATIONS ARE BAD!
Mutations in somatic cells cannot be passed down.Mutation in a gamete MIGHT be passed down.
Genes= Sections of DNA that control our traits • Alleles= different forms of a gene Example: Height of plant could be Tall and Short • Dominant: Stronger allele that can over power the weaker allele T=tall • Recessive: The weaker allele. t=short
Genotypeactual alleles an individual has for a trait Homozygous • Both alleles are the same • Ex. BB or bb Heterozygous • Both alleles are different • Ex. Bb
Phenotype Physical appearance Tall or short
Punnett Square Review Cat fur color Black is dominant: B White is recessive: b Cross a white cat with a heterozygous black cat. What is the chance of having another white kitten in the litter? bb Bb
Results of Punnett Square 50% Hybrid Black and 50% Purebred White bb x Bb b b Bb Bb B Bb bb bb b
Mendel’s Laws • Law of Dominance 2. Law of Segregation – alleles separate when forming gametes 3.Law of Independent Assortment: Alleles segregate independent from one another
Multiple Alleles Definition • Three or more alleles of the same gene that code for a single trait as in blood type. • Example: A, B, O alleles
Sex Determination • 23 pairs of chromosomes in every cell (46) • 1st-22nd pair are autosomes • Pair 23 are reproductive chromosomes • Females XX • Males XY
X-linked Traits Some traits only exist on the X chromosome. If there is a mutation on a gene that is located on the X chromosome, it is called an X-linked disorder. Ex: Color blindness, muscular dystrophy, male pattern baldness, and hemophilia. • Boys are most often affected and inherit it from their mother
What is the chance that a man who is normal but a woman who is a carrier for hemophilia will have a child with hemophilia?
Biotechnology EMERGING ISSUES IN GENETICS
DNA Electrophoresis • A technique used to separate compounds such as DNA and protein based on size by applying an electrical field.
Genetic Engineering • Cut genes out with restriction enzymes • Paste them into a bacterial plasmid = makes recombinant DNA
Genetically Modified Organisms • Examples: • Animals • Bacteria can “eat” oil and radioactive wastes • Extra growth hormone genes to grow faster • Plants • Disease & insect resistance • More nutritional value • Bigger, tastier fruits & veggies
Bacteria have been engineered (genetically modified) to make pharamceuticals
Cloning • Clone = genetically identical cells produced from a single cell • Dolly, the sheep, was a clone • Ethical issues? • Uses? • Medical • Save endangered species