Biology ch 8

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Biology ch 8
2013-03-03 19:40:54

things to know
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  1. Clones
    Genetically identical copy of an organism.
  2. Chromosome
    A structure that consists of DNA and associated proteins; carries part or all of a cell's genetic information.
  3. Sister chromatid
    One of two attached DNA molecules of a duplicated eukaryotic chromosome.
  4. Centromere
    Constructed region in eukaryotic chromosome where sister chromatids are attached.
  5. Histone
    Type of protein that structurally organizes eukaryotic chromosomes.
  6. Nucleosome
    A length of DNA wound twice around a spool of histone proteins.
  7. Chromosome number
    The sum of all chromosomes in a cell of a given type.
  8. Diploid
    Having two of each type of chromosome characteristics of the species (2n).
  9. Karyotype
    Image of an individual's complement of chromosomes arranged by size, length, shape, and centromere location.
  10. Autosome
    Any chromosome other than a sex chromosome.
  11. Sex chromosome
    Member of a pair of chromosomes that differs between males and females.
  12. What are chromosomes?
    • A chromosome consists of a molecule of DNA that is structurally organized by proteins. the organization allows DNA to pack tightly.
    • A eukaryotic cell's DNA is divided among some characteristic number of chromosomes, which differ in length and shape.
    • Members of a pair of sex chromosomes differ between male and females. Chromosomes that are the same in males and females are called autosomes.
  13. Bacteriophage
    Virus that infects bacteria.
  14. What is the molecular basis of inheritance?
    DNA is the material of heredity common to all life on earth.
  15. DNA sequence
    order of nucleotide bases in a strand of DNA.
  16. What is the structure of DNA?
    • A DNA molecule consists two nucleotide chains(strands) running in opposite directions and coiled into a double helix. Internally positioned nucleotide bases hydrogen bond between the two strands. a Pairs with T, and G with C.
    • The sequence of bases along a DNA strand is genetic information. DNA sequences vary among species and among individuals  this variation is the basis of life's diversity.
  17. DNA replication
    Process by which a cell duplicates its DNA before it divides.
  18. DNA polymerase
    DNA replication enzyme. Uses DNA template to assemble a complementary strand of DNA.
  19. Primer
    a Short, single strand of DNA that base-pairs with a targeted DNA sequence.
  20. DNA Ligase
    Enzyme that seals gaps in double-stranded DNA.
  21. Semiconservative replication
    Describes the process of DNA replication, which produces two copies of a DNA molecule: one strand of each copy is new, and the other is a strand of original DNA.
  22. How is DNA copied?
    • DNA replication is an energy-intensive process by which a cell copies its chromosomes.
    • Each strand of a double helix serves as a template for synthesis of a new, complementary strand of DNA.
  23. Mutation
    Permanent change in the nucleotide sequence of DNA.
  24. What are mutations?
    • Permanent changes in s DNA sequence are mutations.
    • DNA damage by environmental agents such as UV light ans chemicals can result in mutations, because damaged DNA is not replicated very well.
    • Proofreading and repair mechanisms usually maintain the integrity of a cell's genetic information by fixing damaged DNA or correcting misprinted bases.
  25. Reproductive cloning
    Technology that produces genetically identical individuals.
  26. Somatic cell nuclear transfer (SCNT)
    Method of reproductive cloning in which genetic material is transferred from one adult somatic cell into am unfertilized, enucleated egg.
  27. Therapeutic cloning
    The use of SCNT to produce human embryos for research purposes.