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Genetics: Study of Heredity

Genetics: Study of Heredity. Aim: What is Genetics?. http://www.youtube.com/watch?v=eOvMNOMRRm8. Sexual Reproduction:. Two parents Half of the genetic information is received from one parent, half from the other. Variation  Evolution. Asexual Reproduction:. One parent

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Genetics: Study of Heredity

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  1. Genetics: Study of Heredity

  2. Aim: What is Genetics? http://www.youtube.com/watch?v=eOvMNOMRRm8

  3. Sexual Reproduction: • Two parents • Half of the genetic information is received from one parent, half from the other. • Variation Evolution

  4. Asexual Reproduction: • One parent • Offspring is identical to parent. • Clones- identical genetic copies.

  5. Genetics: • Gregor Mendel- 1800’s • “Father of Genetics” • Pea plants: easy to grow • Contrasting traits • Easily self and cross pollinate. • From his studies, Mendel arrived at conclusions that are the basis for genetics today!

  6. Additional Vocabulary • Genetics: Study of heredity • Heredity: Passing of genetic information from an organism to it’s offspring.

  7. Genes: units of heredity • Determines traits/ characteristics an offspring will have. • Located on chromosomes. • For each trait-> minimum of 2 genes. One from mom, one from dad. • There are many genes located on a Chromosome.

  8. Genes

  9. Hereditary Information: • DNA- deoxyribonucleic acid • Organic (C, H, O, N, P). • Double stranded • Organized in the form of genes located on the chromosomes.

  10. Hereditary Information:cont. • Homologous chromosomes- are same size and shape (one from each parent) • This allows for crossing over and variation to occur. http://www.youtube.com/watch?v=lJzZ7p-47P8

  11. Genotype vs. Phenotype: • Genotype- genes • Ex: B,b,S,s • Phenotype-Physical appearance • Ex: Fur Color, Fur Length http://www.youtube.com/watch?v=jHWJqzlHl3w

  12. Genetic Recombination: • Sperm and egg combine to form a new cell. • New cell (offspring) has a complete set of genetic information (DNA). Each offspring is unique.

  13. Structure of DNA was discovered by 2 scientists: 1953 James Watson and Francis Crick Created a model known as the Double Helixa twisted ladder. The Genetic Code:

  14. What is the structure of DNA?

  15. Structure of DNA • Long chain of repeating units ( polymer) called nucleotides. • A nucleotide unit contains:1. phosphate group O2. deoxyribose (sugar)3. nitrogenous base: • A- adenine • T- thymine • C- cytosine • G- guanine

  16. Structure of DNA

  17. One Strand of DNA phosphate • The backbone of the molecule is alternating phosphate and deoxyribose, a sugar, parts. • The teeth are nitrogenousbases. deoxyribose bases

  18. Two Stranded DNA • Remember, DNA has two strands that fit together something like a zipper.

  19. A= adenine G= guanine C= cytosine T= thymine Types of nitrogen bases

  20. Structure of a Double Helix • Sides of the “ladder” are alternating phosphate group and deoxyribose sugar. • “rungs” of the ladder are made of 2 nitrogenous bases. • Specific pairings: • There is a weak Hydrogen bondBetween the base pairs. • Structure as a double helix • When a cell goes through mitosis(cell division) the DNA must also make a copy of itself.

  21. The earth is 150 billion m or 93 million miles from the sun. DNA by the numbers • Each cell has about 2 m of DNA. • The average human has 75 trillion cells. • The average human has enough DNA to go from the earth to the sun more than 400 times. • DNA has a diameter of only 0.000000002 m.

  22. Aim: How does DNA replicate? Do Now: Please answer the questions on the handout found on the front desk, omit questions 5-7.

  23. Genetics Can Tell All G-Guanine C-Cytosine T-Thymine A-Adenine

  24. Base Pairing • Which bases always match up? • A-T • G-C • Adenine always binds with Thymine • Cytosine always binds with Guanine

  25. 1.DNA unwinds 2. DNA unzips 3. Old strands become templates for new strands 4. Result- 2 identical DNA molecules Steps of Replication:

  26. Characteristics of a Double Helix • Proteins and Cell Functioning: • Proteins- long chains formed from 20 kinds of amino acids. • Sequence(order) of the amino acids influences the shape of the molecule. • Proteins include: enzymes, insulin, eye color, and skin color.

  27. DNA- Protein Connection: • Genes contain coded information. • This information is used to make proteins that are required for it’s function and structure. • Ribosomes construct proteins based on the cell’s DNA code (combo of A, C, T, G’s). • Parent and offspring produce similar traits that is why there is resemblance between them. They produce similar proteins.

  28. Aim: How does protein synthesis Work?

  29. Protein Synthesis: • The building of protein molecules. • Synthesizing protein from DNA. • Proteins are chains of amino acids.

  30. Steps: • Begins in the nucleus with DNA. • DNA code is read by a “ messenger molecule” messenger RNA; ; • mRNA. • “messenger molecule: travels into the cytoplasm of the cell to the ribosome.

  31. Steps cont.: • With the help of “transfer molecules” tRNA amino acids move to the ribosomes to make proteins. • The ribosomes “reads” the code and a chain of amino acids is produced forming a protein. • ***Protein structure is determined by DNA***

  32. RNA: • Ribonucleic Acid • Single stranded • Nitrogenous bases • A- adenine • U- uracil • C- cystosine • G- guanine

  33. Types of RNA • Messenger RNA (mRNA)Copies code from DNABrings to ribosome • Transfer RNA (tRNA)Brings amino acids to ribosome for protein assembly • Mutations:Alteration of DNA sequence.Causes a change in code carried for by the gene.Random, but can be increased because of chemicals, radiation.

  34. Aim: What are different genetic mutations? • Do Now: Please complete the handout on the front desk.

  35. Different Types of Mutations: • Original DNA Template C A A T G C T A C • 1. Substitution: one base pair for another.C A A C G C T A C • 2. Deletion: missing a base.C A A T O C T A C • 3. Addition: adding an extra baseC A A T A G C T A C • 4. Inversion: bases are rearranged.C A G A T C T A C

  36. Causes of Mutations • Environmental Conditions can affect how genes are expressed. • Ex. Himalayan rabbit • Warmer body temperature white fur • Colder body temperature black fur • ** Identical twins- separated- different personalities • Chemicals, hormones can activate a gene, causing certain proteins to be produced.

  37. Genetic Engineering • Used to alter instructions in organisms. • Produce more desirable traits.

  38. Selective Breeding: • Produces animals and plants with desirable traits. • Horse & donkey= mule. (outbreeding) • Ex. Larger, juicier fruits… • Pure dog, pure cat. (inbreeding)

  39. Inbreeding/ Outbreeding

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