mitosis, meiosis, DNA

• Haploidy


  Being haploid means to have one setof chromosomes, such as in gametes(sex cells)
• Diploidy


  Being diploid means to have two setsof chromosomes, such as in skin cells(somatic cells)
• Aneuploidy


  Being aneuploid means to have anincorrect number of chromosomes,such as with Trisomy
• Which processes contribute to genetic variation during meiosis and when do they occur?

  Crossing Over, which occurs during Prophase I and Independent Assortment, which occurs during Metaphase I
• what's the difference between mitosis and meiosis?

  Mitosis = cell replication results (1 cell = 2 cells)

  
  

  Meiosis = daughter cells have different genetic coding than the parent cells
• What occurs in this phase? prometaphase


  -Nuclear envelope has disappeared

  -Microtubules attach to kinetochores

  -Centrosomes are move towards opposite
• What occurs in this phase? metaphase


  -The chromosomes are lined up in the middle

  -Each sister chromatid of the chromosomeis attached to a spindle fiber on oppositeends
• What occurs in this phase? telophase


  -Chromosomes arrive at opposite poles and begin to decondense

  -Nuclear envelope begins to reform

  -Cell membrane beings to pinch
• What occurs in this phase? anaphase


  -Cohesin proteins holding chromatids together dissolve

  -Sister chromatids are separated and pulled to opposite ends

  -Spindle fibers not connected to thechromatids are elongating the cell
• What occurs in this phase? prophase


  -DNA condenses into chromosomes

  -Nucleus starts to breakdown

  -Spindle Fibers start to emerge
• chromosome


  dan that has been condensed
• kinetochores and centromeres


  Kinetochores are structures that spindle fibers attach to and centromeres are theregion that links chromatids together.
• Nondisjunction


  Error in meiosis in which homologous chromosomes fail to separate.
• what happens during interphase

  The cell grows, copies its DNA, and prepares for cell division.
• During the DNA Extraction ,why did we heat the water to 55, and not higher?

  The heat (55 C):

  • softens the phospholipids of the cell and nucleus

  • Inactivates DNAses

  • Does not denature the DNA(a higher temp of 80C will denature/destroy the DNA)
• How does an agarose gel work?

  An agarose gel separates DNA according to its

  size and uses the charge of the molecule to pull the DNA strands across
• What was the purpose of using soap/detergent during the DNA Extraction?

  To capture the lipids and proteins and aid in releasing the DNA into the environment
• why do we do a pcr?

  Make a lot of copies of DNA
• why is it that the tubulin control gene is always located above the GMO gene?

  the tubulin gene is a control, so it always stays in the same place
• what causes DNA to move through the gel from the top of the ladder to the bottom?

  gravity.
• Which of the following is incorrect?

  
  

  a) Denaturation is supposed to split the double stranded DNA into single strands

  b) Annealing involves primers complimentarily attaching to single stranded DNA

  c) Extension uses Taq polymerase to extend the primers to make a full complimentarystrand

  d) Gel Electrophoresis is involved in making DNA copies

  d) Gel Electrophoresis is involved in making DNA copies