Nucleus

• Do red blood cells have a nucleus?

  No, they do not have a nucleus
• How many nuclei do most cells have?

  Most cells have one nucleus
• What type of nucleus do white blood cells have?

  White blood cells have a lobed nucleus
• Where is ribonucleic acid (RNA) found?

  RNA is found in the cell and nucleus
• What is the role of RNA in the cell?

  RNA manufactures proteins, enzymes, and hormones
• Where is deoxyribonucleic acid (DNA) found?

  DNA is found in the chromatin network and chromosomes
• What is the function of DNA in the cell?

  DNA controls the cell and passes on genes
• What is the chromatin network?

  It is a dark tangled mass in the nucleus
• When is the chromatin network visible?

  It is visible during the resting phase (interphase)
• What does the chromatin network contain?

  It contains genetic information (DNA)
• What surrounds the nucleus?

  The nucleus is surrounded by a nuclear envelope
• What is the nuclear envelope?

  It is a double membrane surrounding the nucleus
• What are nuclear pores?

  Nuclear pores are perforations in the nuclear envelope
• What is the function of nuclear pores?

  Nuclear pores allow movement of molecules
• What is the nucleolus?

  The nucleolus is a small dense disc in the nucleus
• What is the composition of the nucleolus?

  The nucleolus is made up of proteins and RNA
• What are the main functions of the nucleus?

  • Contains genetic information (DNA)
  • Controls cell activities
  • Manufactures ribosomes in the nucleolus
  • Regulates gene expression
• What are the differences between RNA and DNA?

  • RNA:
  • Single-stranded
  • Involved in protein synthesis
  • DNA:
  • Double-stranded
  • Contains genetic blueprint
• Chromatin- when a cell is not dividing you cannot see any chromosomes. This is because DNA is unwound and is spread out in the nucleus