Topic 6 - Inheritance, Variation and Evolution

• What does DNA stand for?

  Deoxyribonucleic acid
• What is the primary function of DNA?

  It contains coded information for organisms
• What determines inherited characteristics in an organism?

  What is in the DNA
• Where is DNA found in cells?

  In the nucleus
• How do chromosomes typically exist?

  In pairs
• What is the structure of DNA?

  Two strands coiled in a double helix
• What is a gene?

  A small section of DNA on a chromosome
• What does each gene code for?

  A particular sequence of amino acids
• How many amino acids are used to make proteins?

  Twenty
• What role do genes play in protein synthesis?

  They dictate the order of amino acids
• What is the function of DNA in relation to proteins?

  It determines what proteins the cell produces
• What is a genome?

  The entire set of genetic material in an organism
• Why is understanding the human genome important?

  It helps identify genes linked to diseases
• How can studying genomes help trace human migration?

  By identifying genetic differences among populations
• What are nucleotides?

  Repeating units that make up DNA strands
• What are the components of a nucleotide?

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

  Sugar and phosphate groups alternate
• What is complementary base pairing?

  A pairs with T, and C pairs with G
• How is the order of amino acids in a protein determined?

  By the order of bases in a gene
• How many bases code for each amino acid?

  Three bases
• What is the role of mRNA in protein synthesis?

  It carries the code from DNA to ribosomes
• Where are proteins made in the cell?

  In the cytoplasm on ribosomes
• What happens to a chain of amino acids after assembly?

  It folds into a unique shape
• What is the function of enzymes?

  To speed up chemical reactions
• What is a mutation?

  A random change in an organism's DNA
• How can mutations affect proteins?

  They can change the protein's structure and function
• What are insertions in DNA mutations?

  New bases added to the DNA sequence
• How do insertions affect the DNA sequence?

  They change how groups of three bases are read
• What are deletions in DNA mutations?

  Random bases removed from the DNA sequence
• What are substitutions in DNA mutations?

  Random bases changed to different bases
• What is sexual reproduction?

  Combining genetic information from two organisms
• How many chromosomes do gametes contain?

  23 chromosomes
• What happens during fertilization?

  The egg and sperm fuse to form a cell
• Why do offspring inherit features from both parents?

  They receive a mixture of chromosomes from both
• What is the advantage of genetic variation in offspring?

  It increases the chance of survival in changing environments
• What is asexual reproduction?

  Reproduction involving only one parent
• How does asexual reproduction occur?

  By mitosis, dividing an ordinary cell
• What is a clone?

  A new cell genetically identical to the parent
• What is the process of meiosis?

  Two cell divisions to produce gametes
• What happens to chromosomes during meiosis?

  They are shuffled and divided into gametes