Cell biology

• What is the first topic for AQA GCSE Biology?

  Cell structure
• What are the two types of cells mentioned?

  Eukaryotic and prokaryotic
• What is the function of the nucleus in a cell?

  Controls cell activities and contains DNA
• What is the role of cytoplasm in a cell?

  Where chemical reactions take place
• What does the cell membrane do?

  Controls what goes in and out of the cell
• What are ribosomes responsible for?

  Making proteins from amino acids
• How do mitochondria function in a cell?

  They release energy by respiration
• What is the function of the cell wall in plant cells?

  Provides strength and support
• What is contained in the sap vacuole?

  Cell sap, a sugary solution
• What is the role of chloroplasts in plant cells?

  Absorb sunlight for photosynthesis
• What are subcellular structures?

  Parts of a cell with specific functions
• What type of cells are prokaryotic cells?

  Bacterial cells
• What do prokaryotic cells lack?

  No nucleus or membrane-bound structures
• What is the approximate size of an animal cell?

  10 micrometers
• What is the approximate size of a plant cell?

  50 micrometers
• What is the approximate size of a prokaryotic cell?

  5 micrometers
• What is cell differentiation?

  • Process where undifferentiated cells become specialized
  • In animals: nerve, muscle, and sperm cells
  • In plants: xylem, phloem, and root hair cells
• What happens to specialized cells when they divide?

  They repair and replace themselves
• What is the function of nerve cells?

  Transmit impulses around the body
• What is the role of mitochondria in sperm cells?

  Provide energy for tail movement
• What does the acrosome in sperm cells contain?

  Enzymes for penetrating the egg cell
• What is the function of muscle cells?

  Contract to allow body movement
• What are xylem cells responsible for?

  Transporting water in plants
• What is lignin's role in xylem cells?

  Supports xylem cells and prevents collapse
• What is the function of phloem cells?

  Transport sugars and nutrients in plants
• What do root hair cells do?

  Absorb water and minerals from soil
• What are the differences between light and electron microscopes?

  • Light microscopes: low magnification, low resolving power
  • Electron microscopes: high magnification, high resolving power
  • Electron microscopes provide higher resolution images
• What are the units used for measuring sizes of subcellular structures?

  Millimeters, micrometers, and nanometers
• How do you convert millimeters to micrometers?

  Multiply by 1,000
• What is the formula for magnification?

  Magnification = size of image / real size
• If the image size is 5 mm and the real size is 20 micrometers, what is the magnification?

  250
• If the magnification is 2000 and the image size is 10 mm, what is the real length?

  5 micrometers
• What are the stages of the cell cycle?

  1. Stage 1: Cell growth and structure increase
  2. Stage 2: Mitosis (chromosomes line up and divide)
  3. Stage 3: Cytoplasm and membranes divide
• What is the purpose of mitosis?

  To repair and grow tissues
• What are stem cells and their types?

  • Embryonic stem cells: undifferentiated, can become any cell type
  • Adult stem cells: found in bone marrow, mainly blood cells
  • Plant stem cells: found in meristem tissue, can differentiate into any plant cell
• What is therapeutic cloning?

  Cloning cells for medical treatment
• What is diffusion?

  Spreading of particles from high to low concentration
• What is the net movement in diffusion?

  From higher concentration to lower concentration
• What is equilibrium in diffusion?

  Equal concentration on both sides
• What are some objections to stem cell procedures?

  Viral infection risks and moral objections