DNA & Inheritance

• What controls the activities of a cell?

  The nucleus
• How does DNA control cell activities?

  By a chemical code for amino acids
• What are the functions of DNA?

  • Forms a chemical code for proteins
  • Varies among different people or cells
  • Determines chemical reactions in cells
• What is DNA made up of?

  Two long chains of sugar and phosphate
• What forms the double helix structure of DNA?

  Pairs of bases connected together
• How many bases are there in DNA?

  Four
• What are the four bases of DNA?

  Adenine, thymine, guanine, cytosine
• What is genetic profiling used for?

  • Analyzing fingerprints from crime scenes
  • Identifying species relationships
  • Detecting genes associated with traits
• How does genetic profiling work?

  By analyzing DNA samples for similarities
• What are the steps in genetic profiling?

  1. Collect a sample of cells
  2. Break up the cells
  3. Cut DNA into fragments
  4. Separate fragments and develop patterns
• What is a gene variant called?

  Allele
• What does homozygous mean?

  Having the same alleles
• What does heterozygous mean?

  Having different alleles
• What is monohybrid inheritance?

  • Inheritance of a single gene
  • Example: Tall vs. short peas
  • Dominant allele shows in phenotype
• What is the dominant allele for height in peas?

  Tall (T)
• What genotype produces a short phenotype in peas?

  tt (two recessive alleles)
• What determines gender in organisms?

  • Chromosomes (XX for female, XY for male)
  • Genetic makeup influences traits
• What are the advantages of genetic engineering?

  • Crops can survive difficult conditions
  • Increased yield of food crops
  • Plants can produce useful substances
• What are the disadvantages of genetic engineering?

  • Potential for environmental impact - reduces biodiversity
  • Ethical concerns about modification, e.g. consent issues
  • effects market resistance, impacting farmers and companies involved with genetic engineering
  • modifying DNA can have unexpected effects
• What can genetically modified crops resist?

  Pests and herbicides
• What are some concerns regarding genetic engineering?

  • can harm other plants
  • ethical issues - nit right to interfere with nature
  • expensive - developing countries cannot afford
  • can be harmful
  • can cause allergic reactions
• What is DNA primarily composed of?

  Double stranded polymer of nucleosides
• What are the components of each DNA strand?

  Sugar and phosphate molecules
• How many bases are there in DNA?

  Four bases
• Which bases pair together in DNA?

  A pairs with T and C pairs with G
• What is a gene?

  A section of DNA that codes for protein
• What forms a triplet code in genetics?

  Three bases form a triplet code
• What does each triplet code specify?

  It codes for an amino acid
• What are the steps in genetic profiling?

  1. Sample of cells collected
  2. DNA extracted from cells
  3. DNA sample cut into fragments using enzymes
  4. Fragments separated into bands
• What is one use of genetic profiling?

  Paternity testing
• What is an allele?

  A version of a gene
• What is a gamete?

  Reproductive cells
• What is a dominant allele?

  An allele that is always expressed
• What is a recessive allele?

  An allele expressed in absence of dominant allele
• What does homozygous mean?

  Two identical alleles of a gene
• What does heterozygous mean?

  Two different alleles of a gene
• What is genotype?

  Genetic composition
• What is phenotype?

  Observable characteristics
• What are the male and female chromosomes?

  XY for males, XX for females
• What is genetic engineering?

  • Modification of an organism's genome
  • Insertion of a gene from another organism
  • Allows formation of genetically modified organisms