Definitions

• What is sexual reproduction?

  It involves the joining of male and female gametes.
• What are the gametes in animals?

  Sperm and egg cells.
• How are gametes formed?

  By meiosis.
• How many chromosomes does a normal cell have?

  46 chromosomes.
• How many chromosomes does each gamete have?

  23 chromosomes.
• What happens during fertilization?

  Gametes fuse to produce a cell with 46 chromosomes.
• What is the result of sexual reproduction?

  Variation in the offspring.
• What is asexual reproduction?

  It involves one parent with no gametes joining.
• How are cells formed in asexual reproduction?

  Through mitosis, producing two identical cells.
• What is the outcome of asexual reproduction?

  Clones that are genetically identical to each other and the parent.
• What are the advantages of sexual reproduction?

  • Produces variation in offspring.
  • Increases survival advantage in changing environments.
  • Decreases the chance of extinction.
• What are the advantages of asexual reproduction?

  • Only one parent is needed.
  • Allows for selective breeding.
  • Uses less energy and is faster.
• What is the role of meiosis?

  To produce haploid gametes (sperm and egg cells).
• How many non-identical cells are formed from one cell during meiosis?

  Four non-identical cells.
• What happens to the chromosomes during meiosis?

  The cell makes copies of its chromosomes and then divides.
• What is the chromosome number after the first division in meiosis?

  Each cell has half the amount of chromosomes (46).
• What is the chromosome number after the second division in meiosis?

  Each cell has a quarter the amount of chromosomes (23).
• Why are gametes genetically different from each other?

  Because the chromosomes are shuffled during the process.
• What happens after fertilization?

  The cell divides by mitosis to produce many copies.
• What is differentiation?

  When cells begin to take on different roles.
• What does DNA stand for?

  Deoxyribonucleic acid.
• What is the structure of DNA?

  It is a polymer made up of two strands twisted together.
• What are the components of a nucleotide?

  One sugar molecule, one phosphate molecule, and one of four organic bases.
• What are the four types of organic bases in DNA?

  A, C, G, T.
• What is complementary base pairing?

  A bases connect to T bases, and C bases connect to G bases.
• What is a gene?

  A short section of DNA that codes for amino acids to make a specific protein.
• How many types of amino acids are there?

  20 types of amino acid.
• What does the term genome refer to?

  All the genetic information of a single organism.
• What is the purpose of extracting DNA from fruit?

  To visualize the DNA using household ingredients.
• What are the steps to extract DNA from fruit?

  1. Mix cold water, salt, and washing up liquid; heat.
  2. Chop and pulverize the fruit.
  3. Add the solution to the fruit.
  4. Filter the solution.
  5. Add pineapple juice and rest.
  6. Add cold ethanol and wait.
• What should be observed after adding ethanol in DNA extraction?

  A white mass should precipitate at the top of the tube.
• Why is pineapple juice added during DNA extraction?

  It contains bromelain, which breaks down proteins attached to DNA.
• What is protein synthesis?

  The process of producing a protein from DNA.
• What does each group of three bases in DNA code for?

  An amino acid.
• What determines the type of protein produced?

  The different types and order of amino acids.
• What are non-coding parts of DNA responsible for?

  Switching genes on or off.
• What is the role of RNA polymerase in protein synthesis?

  It binds to non-coding DNA to initiate mRNA synthesis.
• What happens to mRNA after it is synthesized?

  It moves out of the nucleus to the cytoplasm and ribosomes.
• How are amino acids brought to the ribosomes?

  By carrier molecules called tRNAs.
• What happens when the amino acids connect together?

  They form a polypeptide linked by peptide bonds.