B1.3 DNA

• What does DNA stand for?

  Deoxyribonucleic acid
• What is DNA made of?

  It is made of genetic material
• What type of molecule is DNA?

  Polymer
• How many strands does DNA have?

  Two strands
• What shape does DNA form?

  Double helix
• If you unraveled DNA from a single cell, how long would it be?

  Over two meters long
• How is DNA organized in the nucleus?

  Separated into 46 different sections
• What are the tightly coiled sections of DNA called?

  Chromosomes
• How many chromosomes does each human cell have?

  46 chromosomes
• How many different types of chromosomes are there?

  23 different types
• What do we call the pairs of chromosomes?

  Chromosome pairs
• What are the sex chromosomes in humans?

  X and Y chromosomes
• What chromosomes do women have?

  Two X chromosomes
• What chromosomes do men have?

  One X and one Y chromosome
• When do chromosomes appear in an X shape?

  Just before cell division
• What is a gene?

  A small section of DNA coding for protein
• What does a gene code for?

  A particular sequence of amino acids
• How many different types of amino acids are there?

  20 different types
• What determines the type of cell produced?

  The proteins the cell produces
• What protein do red blood cells need?

  Hemoglobin
• What is a genome?

  The entire set of genetic material
• How does my genome compare to a stranger's?

  It would be quite different
• How does my genome compare to my parents' genomes?

  It would be more similar
• How does the genome of identical twins compare?

  They have the same genome
• What have scientists worked out regarding the human genome?

  They know the entire code of DNA
• How can genes be linked to diseases?

  They may cause or increase disease risk
• What is an inherited disease?

  A disease inherited from parents' genes
• What is the role of doctors in relation to genes?

  They choose effective treatments based on genes
• How can genomes help trace human migrations?

  Small differences indicate population separations
• What can we learn from the small differences in genomes?

  When populations separated in history
• What are the relationships between DNA, chromosomes, genes, and genomes?

  • DNA is the genetic material.
  • Chromosomes are tightly coiled DNA sections.
  • Genes are segments of DNA coding for proteins.
  • The genome is the complete set of genetic material.
• What are the functions of proteins in cells?

  • Transport molecules (e.g., hemoglobin)
  • Facilitate cellular processes (e.g., muscular contraction)
  • Determine cell type and function
• What are the implications of understanding the human genome?

  • Identifying genes linked to diseases
  • Developing targeted treatments
  • Tracing human ancestry and migrations
• What is an allele?

  A different version of the same gene
• What is the difference between dominant and recessive alleles?

  Dominant alleles are expressed over recessive ones
• What does homozygous mean?

  Having two identical alleles for a gene
• What does heterozygous mean?

  Having two different alleles for a gene
• What is a gene?

  A segment of DNA coding for a protein
• How do genes determine characteristics?

  They code for proteins that influence traits
• Can a single gene determine a trait?

  Yes, sometimes traits are single-gene determined