Human Biology

• What determines an organism's phenotype?

  Proteins produced from gene expression
• Why are only a fraction of genes expressed in a cell?

  Only necessary genes for function are activated
• How is gene expression regulated?

  By controlling transcription and translation
• What is a cell's genotype determined by?

  Sequence of DNA bases in its genes
• What happens to genes in a specialized cell?

  Only genes needed for functions are activated
• What is the process of differentiation in cells?

  Stepwise changes in gene expression occur
• What is gene expression?

  Activation of a gene to form a protein
• What influences gene expression?

  Intra- and extra-cellular environmental factors
• What is the structure of RNA?

  Single stranded with ribose sugar
• What base does RNA contain instead of thymine?

  Uracil
• What does mRNA do?

  Carries DNA code to the ribosome
• What forms the ribosome?

  Ribosomal RNA (rRNA) and proteins
• What does each tRNA carry?

  A specific amino acid
• What is the primary structure of a protein?

  The polypeptide chain of amino acids
• What happens during RNA splicing?

  Introns are removed, exons are joined
• What is the role of RNA polymerase in transcription?

  It synthesizes RNA from the DNA template
• What is a codon?

  A triplet of bases on mRNA
• What is the function of the ribosome during translation?

  It facilitates the assembly of amino acids
• What is the significance of start and stop codons?

  They signal the beginning and end of translation
• What is the final structure of a protein called?

  Tertiary structure
• What bonds hold the tertiary structure of proteins together?

  Hydrogen bonds and sulfur bonds
• What is the role of enzymes in biological processes?

  They catalyze biochemical reactions
• What are the functions of proteins?

  • Enzymes (e.g., amylase)
  • Structural proteins (e.g., collagen)
  • Hormones (e.g., insulin)
  • Antibodies (e.g., immunoglobulins)
• What is alternative RNA splicing?

  • Different segments treated as exons/introns
  • Produces various mRNA molecules
  • Leads to different polypeptide chains