Genetics Unit

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Genetics Unit Cell Reproduction

• Asexual reproduction
• Binary fission
• Mitosis
• Sexual reproduction
• Meiosis
• Meiosis I, meiosis II
• gametes

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Genetics Unit Chpt. 9Punnett Squares

• Probability
• Punnett square
• Monohybrid, dihybrid
• Dominant, recessive, homozygous, heterozygous
• Incomplete, Co-dominant and x-linked traits

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Genetics Unit Gregor Mendel

• Father of modern genetics
• 1st to apply mathematics of statistics to
  crosses, 1840s, Austria, monastery gardens
• Genetics ? field of biology devoted to
  understanding HOW characteristics are transmitted
  from parents to offspring
• Heredity ? the transmission of characteristics
  from parents to offspring

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Mendels Laws

1. Law of Segregation pair of factors is separated
   during the formation of gametes
2. Law of Independent Assortment factors for
   different traits are distributed to gametes
   independently

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Molecular Genetics

• Molecular genetics ? is the study of the
  structure and the function of the chromosomes and
  the genes.
• This would include mapping the genome, locating
  markers for diseases, making proteins and
  technology like cloning, genetic engineering and
  DNA fingerprinting.

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Genetics Unit- Nucleic acids and protein
synthesis

• DNA organic compound made of repeating subunits
  called nucleotides.
• A DNA nucleotide has three parts
• Sugar (deoxyribose)
• Phosphate group (PO4)
• Nitrogen containing base (A,T,C,G)
• Adenine, thymine, cytosine and guanine

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Watson and Crick

• James Watson and Francis Crick are the
  discoverers of the DNA double helix
• 1953, Cambridge, England
• Built a wooden model based on other research ,
  including x-ray crystallography
• Other scientists involved where Rosalind
  Franklin, Linus Pauling, Maurice Wilkins

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Complementary Base Pairing

• Because of the exact shape and size of the DNA,
  the sugars and phosphates make the sides of the
  ladder and the nitogenous bases make the rungs.
  
• A and G (purines) are larger than C and T
  (pyrimidines)
• MUST PAIR UP with A-T and C-G so all rungs are
  the same length.
• A-T and C-G are hydrogen bonds.

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DNA Replication

• During the S portion of interphase
• All DNA is copied so there are 2 complete sets,
  one set for each new cell
• p.188
• DNA helix is untwisted by helicase enzyme
• DNA polymerase enzymes add new bases
• Get two identical strands of double helix

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Mutations

• Change in the nucleotide sequence
• 1 error per 100,000 bases, VERY accurate
• Proof reading enzymes correct allowing for 1
  per billion nucleotide average
• Changes can also be caused by mutagens like
  chemicals and radiation

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RNA

• Single stranded
• Copies of DNA
• Can leave nucleus
• Takes DNA code to the ribosomes so that proteins
  can be manufactured
• Contains the sugar ribose, and the bases A, C, G
  and U (uracil). There is no T in RNA

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RNA Transcription

• DNA is opened, only at the gene/region of
  interest.
• A copy is made by matching A-U and C-G
• The mRNA (leaves) and the DNA reseals. Original
  DNA is intact, undiluted, unchanged and in the
  nucleus.
• RNA strand is EDITTED to delete unnecessary
  regions called introns and the good regions are
  spliced together (exons) and make the final mRNA

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Types of RNA

• mRNA messenger, carries DNA info from the
  nucleus to the cytoplasm
• tRNA transfer (transport), short chain, highly
  folded, binds specific amino acids to the mRNA
• rRNA ribosomal, most abundant version,
  ribosomes are made of protein and rRNA.

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Translation of RNA into protein

• protein synthesis
• mRNA is read by the ribosome in chunks
• Each region of 3 bases on the mRNA is called a
  codon (p.194)
• Each codon signals a specific amino acid
• If you put the right amino acids in the right
  order you have .. A protein.

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Remember..

• Every thing, in every cell, is either made of a
  protein or run by a protein.
• Functions of proteins include
• muscle, structure, storage, immunity,
  identification, communication, and transport

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Genetics Unit Chpt 11Gene Expression

• Gene expression all genes are not on all the
  time. The process of turning on the right genes
  at the right time is gene expression
• Genome complete set of genetic material for an
  individual

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Operons

• Found in bacteria cells very different
  machinery from our cells
• Jacob and Monad
• Operon structural genes promoter operater
• Operons can
• 1. repress protein production (repressor)
• 2. activate protein production (inducer)

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More Chpt. 11 vocabulary

• Cell differentiation the development of cells
  that have specialized functions ( muscle, nerve,
  skin, etc.)
• Morphogenesis the formation of an organism,
  getting the tissues and organs in the right
  places
• Homeotic genes regulatory genes that determine
  where anatomical features go

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CANCER

• Malignant tumors are usually called cancer.
• Tumor abnormal proliferation of cells,
  uncontrolled cell division
• Benign tumor mass of cells
• Malignant tumor uncontrolled cell division that
  invades and destroys healthy tissue
• Metastasis spread of cancer to new sites

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Cancer continued

• Oncogenes genes that cause cancer, code for
  uncontrolled cell growth
• Tumor suppressor genes code for proteins that
  prevented uncontrolled cell division.
• Mutation of tumor suppressor genes cause a
  predisposition to cancers
• Some cancers are now directly linked to viruses
  as their cause .