Inheritance, Variation, and Evolution

• What is meiosis?

  Formation of four non-identical cells
• What is mitosis?

  Formation of two identical cells
• What does sexual reproduction involve?

  Joining of male and female gametes
• How are gametes formed?

  By meiosis, resulting in non-identical cells
• 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 asexual reproduction?

  Involves one parent without gametes joining
• How does asexual reproduction occur?

  Through mitosis, forming identical cells
• What do clones refer to in asexual reproduction?

  Genetically identical organisms
• How do malarial parasites reproduce?

  Sexually in mosquitoes, asexually in humans
• How do fungi reproduce?

  Many species can reproduce both sexually and asexually
• What is pollination in plants?

  Pollen reaching egg cells in flowers
• How do strawberry plants reproduce asexually?

  By producing runners that grow new plants
• How do daffodils reproduce asexually?

  By growing new bulbs from the main bulb
• What is the advantage of asexual reproduction in plants?

  Allows reproduction even if flowers are destroyed
• What is DNA?

  A polymer containing instructions for the body
• What is the structure of DNA?

  Two strands forming a double helix
• What are chromosomes made of?

  Long strands of DNA
• What is a gene?

  A small section of DNA coding for a protein
• What is a genome?

  All genes coding for proteins in an organism
• How has studying the human genome helped medicine?

  Improved understanding of genes linked to diseases
• What does DNA stand for?

  Deoxyribonucleic acid
• What are nucleotides?

  Small parts that make up DNA
• What are the four types of organic bases in DNA?

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

  A pairs with T, C pairs with G
• What does the order of bases in DNA form?

  A code for amino acids
• How many types of amino acids are there?

  20 types of amino acids
• What is protein synthesis?

  Producing a protein from DNA
• What happens if a gene is expressed?

  It is coded to make a protein
• Why can't DNA move out of the nucleus?

  It is too big to leave the nucleus
• What are the roles of proteins?

  • Enzymes: speed up reactions
  • Hormones: send signals in the body
  • Structural proteins: form structures like collagen
• What are mutations?

  Changes in the sequences of bases in DNA
• What happens if a base is inserted into the DNA code?

  It changes how the code is read
• What happens if a base is deleted from the DNA code?

  It changes how the code is read
• What happens if a base is substituted in the DNA code?

  It may change one amino acid or none
• How do mutations affect protein structure?

  Change the sequence of amino acids
• What can happen if a protein's shape is altered?

  Substrate may not fit into the active site
• What can mutations in non-coding DNA affect?

  Whether genes are expressed or not
• What happens during transcription?

  mRNA nucleotides match to DNA bases