Topic 2 Bio

• What are the key organelles in eukaryotic cells that need to be known?

  • Nucleus
  • Endoplasmic reticulum (smooth and rough)
  • Golgi apparatus
  • Lysosomes
  • Mitochondria
  • Ribosomes
  • Vacuole
  • Chloroplasts
  • Cell wall
  • Plasma membrane
• What are the key structures within the nucleus?

  Nuclear envelope, nuclear pores, nucleoplasm, chromosomes, and nucleolus
• What is the overall function of the nucleus?

  DNA replication and transcription of mRNA
• What is produced in the nucleolus?

  RNA and ribosomes
• What is the function of the rough endoplasmic reticulum (RER)?

  Protein synthesis
• What is the function of the smooth endoplasmic reticulum (SER)?

  Synthesis of lipids and carbohydrates
• What is the structure of the Golgi apparatus?

  A folded membrane system making cisternae.
• What happens to molecules in the Golgi apparatus?

  They are modified and packaged for transport
• What are lysosomes involved in?

  Digestion and hydrolysis of materials
• What is the function of mitochondria?

  Site of aerobic respiration and ATP production
• What is unique about the DNA in mitochondria?

  It is a loop similar to prokaryotic DNA
• What size ribosomes are found in eukaryotic cells?

  80S
• What is the function of vacuoles in plant cells?

  To provide turgidity and store substances
• What is the role of chloroplasts?

  Site of photosynthesis
• What is the structure of the chloroplast?

  Double membrane with thylakoid membranes inside
• What is the function of the cell wall in plant cells?

  Provides structural strength and prevents bursting
• What is the composition of the cell wall in plants?

  Cellulose
• What is the composition of the cell wall in fungi?

  Chitin
• What is the function of the plasma membrane?

  Controls entry and exit of substances in the cell
• What are the key differences between prokaryotic and eukaryotic cells?

  Prokaryotic cells are smaller, lack membrane-bound organelles, and have 70S ribosomes
• What is the structure of viruses?

  Genetic material, capsid, and attachment proteins
• How do viruses replicate?

  Inside host cells by injecting their nucleic acid
• What are the methods of studying cells mentioned in the material?

  Microscopy, cell fractionation, and ultra centrifugation
• What is the definition of magnification?

  How many times larger the image is compared to the object
• What is the resolution of a microscope?

  The minimum distance between two objects that can still be viewed as separate
• What determines the resolution of optical microscopes?

  The wavelength of light
• What determines the resolution of electron microscopes?

  The wavelength of the beam of electrons
• What is the main advantage of electron microscopes over optical microscopes?

  Higher resolution due to shorter wavelength
• What type of images do optical microscopes produce?

  Color images
• Why can't living samples be observed using electron microscopes?

  Because samples must be in a vacuum
• What is the eyepiece graticule used for?

  To measure the size of objects viewed under the microscope
• What are the conditions required for cell fractionation?

  Cold, isotonic, and buffered solution
• What is homogenization in cell fractionation?

  Breaking open cells to release their contents
• What is ultra centrifugation?

  Spinning samples at different speeds to separate organelles
• What is the order of density for organelles during centrifugation?

  Nuclei, chloroplasts, mitochondria, lysosomes, endoplasmic reticulum, ribosomes
• What is the cell cycle in eukaryotic cells?

  Includes interphase, mitosis, and cytokinesis
• What happens during interphase?

  The cell grows and DNA is replicated
• What are the stages of mitosis?

  Prophase, metaphase, anaphase, and telophase
• What is produced at the end of mitosis?

  Two genetically identical diploid cells
• How do prokaryotic cells replicate?

  By binary fission