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DNA. By: Mr. Hunter. Bellwork: Fill-In-The Blank. Write the complete sentence. Inherited characteristics are determined by _____ , which are passed from one generation to the next. Genes are parts of _____ , found in the nucleus of the cell. Chromosomes are made of _____ and _____ . . DNA.
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DNA By: Mr. Hunter
Bellwork: Fill-In-The Blank. Write the complete sentence. • Inherited characteristics are determined by _____ , which are passed from one generation to the next. • Genes are parts of _____ , found in the nucleus of the cell. • Chromosomes are made of _____ and _____ .
DNA • What do you know about DNA? • What do you want to know about DNA?
Rosalind Franklin • She used x-ray diffraction to make images of DNA.
DNA • DNA should be able to be copied each time a cell divides. • DNA should be able to give instructions for building and maintaining cells.
DNA • Double helix structure • DNA is composed of nucleotides. • Nucleotides: Adenine, Guanine, Cytosine, Thymine
Nucleotides Nucleotides are made of sugar, phosphate group, and a nitrogenous base.
Mnemonic MNEMONIC Create a mnemonic device that will remind you of the names of the bases and the way the bases form pairs. Example: Atoms are Tiny would help you remember that adenine pairs with thymine.
DNA • DNA strands are complimentary to each other! • For instance, the sequence CGAC will bond to the sequence GCTG. • This assists in DNA replication, which occurs anytime a cell divides.
Write the Sentences and • 1. What would the complimentary strand of DNA be for a DNA strand with this sequence: atgcccgggaaatt? • 2. Briefly describe how each of the following individuals contributed to DNA science: Watson and Crick, Rosalind Franklin, and Chargaff? • 3. A nucleotide consists of a _____, _____, and a ______ . • 4. The shape of DNA is a ______ .
DNA • 1. How does DNA differ in eukaryotic cells differ from DNA in prokaryotic cells? • 2. What is a gene? • 3. Where is the DNA in your cells? • 4. How does so much DNA fit into the nucleus? • 5. What is the name for stands of DNA wound around proteins? • 6. When do chromosomes become visible in cells? • 7. What are chromatids?
DNA-> PROTEIN • List, describe, and draw a picture to detail each step of protein formation.
Protein Synthesis • RNA serves as a temporary copy of a DNA sequence. • 1. DNA strands separate. Free nucleotides attach to one strand of DNA. The nucleotides make up mRNA. • *RNA has uracil instead of thymine. • *It is called messenger RNA because it leaves the nucleus of the cell.
Protein Synthesis • 2. mRNA attaches to a ribosome. (There are 10,000,000 ribosomes in one human cell.) • 3. tRNA (transfer RNA) carrying an anticodonandamino acid affixes to the ribosome. The process of translation begins.
Protein Synthesis • 4. Each codon on the mRNA matches an anticodon on the tRNA. Codons and anticodons are complimentary. • 5. tRNA floats away and leaves its amino acid behind. • 6. The amino acids are assembled into polypeptides (protein molecules).
Transcription - Synthesis of mRNA molecule. • Translation - Synthesis of polypeptide from amino acids. • Codon - Base triplet on mRNA. • Anticodon - Complementary triplet on tRNA. • Polypeptide - Protein molecule
DNA Protein • You are a protein. Write a story of your formation. Include the following words: DNA, mRNA, tRNA, RNA, ribosome
Mutations • Mutation: a change in the nucleotide-base sequence of a gene or DNA molecule • Insertion, deletion, substitution
Mutation Effects • An improved trait • No change • A harmful trait
Mutations • Occur in approximately one out of every 10,000 base pairs. With cellular proofing mechanisms, the final error rate is as low as one in a billion. • Mutations occur because of errors when DNA is copied or mutagens (radioactivity).
Example Sickle Cell Anemia
Copy this! • Human DNA consists of about 3 billion base pairs. If you could print a book with all the genetic information carried in just one human cell, it would be 500,000 pages long!!!!!
Human Genome • There are about 25,000 human genes, and many genes code for multiple proteins. • In this and other ways, human genes appear to be unique among organisms.
Human Genome Project • In 2003, the Human genome Project had successfully mapped 99% of the 3 billion base pairs that make up a set of human DNA. But the project has raised new questions as well.
HUMAN GENOME PROJECT • 3% of base pairs are used to make proteins. • 97% are regulatory sequences, nonfunctioning genes, and sequences with no known function.
CLONING • Cloning is making an exact genetic copy of DNA.
Why clone? Medical Reasons • Cloning animal models of disease • Cloning stem cells for research • “pharming” for drug production Reviving Extinct Species
Why clone? Reproducing a deceased pet Cloning Humans -to help an infertile couple have a child -to replace a deceased child
Misconceptions • Instant clones
Misconceptions • Carbon Copies
What are the problems with cloning? • High failure rate • Problems during later development • Abnormal gene expression patterns
What are the benefits? • Eliminating genetic diseases • Screening unborn babies • Treating diseases
What are the risks? • People can control possible traits in organisms.
Questions to Ponder • 1. This technology could allow a 60-year old woman to have a baby. Do you think this would be a positive or negative outcome of the technology? Why? • 2. During World War II, Nazis in Germany conducted experiments to selectively breed blond, blue-eyed men and women. This is an example of eugenics that was detrimental to society. Explain why.
DNA Extraction http://learn.genetics.utah.edu/content/labs/extraction/