DNA

• What is the primary purpose of reproduction in living organisms?

  To pass on DNA to the next generation
• What does DNA carry that is essential for an organism?

  Instructions for the organism's characteristics
• What are the repeating units that make up DNA strands called?

  Nucleotides
• What are the three components of a nucleotide?

  A sugar, a phosphate group, and a base
• What forms the backbone of DNA strands?

  The alternating sugar and phosphate groups
• How many different bases are there in DNA?

  Four
• What are the four bases found in DNA?

  A (adenine), T (thymine), C (cytosine), and G (guanine)
• What shape does a DNA molecule have?

  A double helix
• How do bases pair in a DNA molecule?

  A pairs with T, and C pairs with G
• What is the term for the pairing of bases in DNA?

  Complementary base pairing
• What type of bonds join the complementary base pairs in DNA?

  Weak hydrogen bonds
• Where are chromosomes found in eukaryotic cells?

  In the nucleus
• What is a gene?

  A section of DNA on a chromosome that codes for a particular protein
• What does the term genome refer to?

  All of an organism's DNA
• What is the procedure to extract DNA from fruit cells?

  1. Mash strawberries and mix with detergent and salt.

  • Detergent breaks down cell membranes.
  • Salt helps DNA stick together.

  1. Filter the mixture to remove froth and insoluble bits.
  2. Add ice-cold alcohol to the filtered mixture.
  3. DNA precipitates as a stringy white solid.
• Why is detergent used in the DNA extraction process?

  It breaks down the cell membranes to release the DNA
• What role does salt play in the DNA extraction process?

  It makes the DNA stick together
• What happens to DNA when ice-cold alcohol is added during extraction?

  It precipitates out of solution as it is not soluble in cold alcohol
• Who were awarded the Nobel Prize for their work on the structure of DNA?

  Crick, Watson, and Wilkins
• In what year was the Nobel Prize awarded for the structure of DNA?

  1962