DNA and inheritance

• What is a gamete?

  Sex cell (sperm or egg)
• What does DNA stand for?

  Deoxyribonucleic acid
• What is the primary function of DNA?

  It carries genetic information
• What is the structure of DNA?

  Two strands forming a double helix
• What is an organism?

  Living entity, e.g., animals or plants
• How is DNA unique in individuals?

  Except for identical twins, it's unique
• Where are chromosomes found?

  In the nucleus of most cells
• What do chromosomes consist of?

  Long threads of DNA made of genes
• What is a gene?

  Basic unit of genetic material
• What are alleles?

  Different versions of the same gene
• What does a gene control?

  Part of a cell's chemistry, especially proteins
• What is heterozygous genotype?

  Two different alleles for a characteristic
• What is homozygous genotype?

  Two identical alleles for a characteristic
• What is a dominant allele?

  Always expresses itself in a heterozygote
• How is a recessive allele expressed?

  Only if paired with another recessive allele
• How are dominant alleles represented?

  By a capital letter
• How are recessive alleles represented?

  By a lowercase letter
• What is the phenotype?

  Visible characteristics resulting from genes
• What is the genotype?

  Collection of alleles for a characteristic
• How do homozygous and heterozygous genotypes differ?

  Homozygous has identical alleles, heterozygous has different
• How do dominant and recessive alleles interact?

  Dominant alleles mask recessive alleles
• What are the key terms used in genetics?

  • Gamete: Sex cell (sperm or egg)
  • DNA: Deoxyribonucleic acid, genetic material
  • Chromosome: Structure made of DNA
  • Gene: Basic unit of genetic material
  • Allele: Different versions of a gene
  • Genotype: Collection of alleles
  • Phenotype: Visible characteristics
  • Dominant allele: Always expressed
  • Recessive allele: Expressed only if homozygous
  • Homozygous: Identical alleles
  • Heterozygous: Different alleles
• What is the structure of DNA responsible for?

  It carries the genetic code of organisms
• What is a gene?

  A section of DNA coding for a protein
• How is genetic information passed on?

  Through heredity from parents to offspring
• Where are chromosomes found in a cell?

  In the nucleus of most cells
• What do chromosomes consist of?

  Long threads of DNA made of genes
• Who discovered the structure of DNA?

  James Watson and Francis Crick
• What did Watson and Crick use to build their DNA model?

  Data from other scientists, including X-ray data
• What is the shape of the DNA molecule?

  A double helix structure
• What forms the backbone of each DNA strand?

  Alternating sugar and phosphate molecules
• How many different bases are there in DNA?

  Four different bases
• What are the four bases in DNA?

  Thymine, adenine, guanine, cytosine
• What is complementary base pairing?

  Specific pairing of bases in DNA strands
• Which bases pair together in DNA?

  Thymine with adenine, guanine with cytosine
• What determines the order of amino acids in proteins?

  The order of bases in the genes
• What is an allele?

  A different form of a gene
• What are the alleles for eye colour?

  Blue and brown eye colour alleles
• How many alleles can a person have for a gene?

  Two alleles, same or different
• What is the triplet code?

  A code of three bases determining amino acids