Biology: Cell structure

• What are the two basic types of cells?

  Prokaryotic and Eukaryotic Cells
• What distinguishes prokaryotic cells from eukaryotic cells?

  Prokaryotic cells lack a nucleus, while eukaryotic cells have one.
• What is the function of the nucleus in a cell?

  It contains genetic material (DNA) and controls cell activities.
• What is the cytoplasm?

  It is a jelly-like substance where cell processes occur.
• What is the role of the cell membrane?

  It is a semi-permeable barrier that controls what enters and exits the cell.
• What are ribosomes responsible for?

  They are the sites of protein synthesis.
• What is the function of mitochondria?

  They are the powerhouse of the cell, involved in aerobic respiration and energy production.
• What is the function of chloroplasts in plant cells?

  They are the site of photosynthesis and contain chlorophyll.
• What is the cell wall and its function in plant cells?

  It provides structure and support and is made of cellulose.
• How does cell specialization occur?

  • Different cells have different structures and functions.
  • Example: Red blood cells for oxygen transport, nerve cells for signaling.
• What are the three main transport mechanisms in cells?

  1. Diffusion: Movement of molecules from high to low concentration.
  2. Osmosis: Diffusion of water across a semi-permeable membrane.
  3. Active Transport: Movement of substances against a concentration gradient, requiring energy.
• What is the maximum magnification of a light microscope?

  Up to 2000x.
• What is the maximum magnification of an electron microscope?

  Up to 2,000,000x.
• What are the key points to review for the AQA Biology exam on cell structure?

  • Basic cell types: Prokaryotic and Eukaryotic.
  • Common organelles and their functions.
  • Cell specialization and transport mechanisms.
  • Stages of the cell cycle.
  • Microscopy techniques and magnifications.
• How can cells be classified?

  According to their structure
• What is the function of ribosomes?

  They synthesize proteins
• If the length of the cell in Figure 1 is 1.5 micrometres (μm), what is its length in millimetres (mm)?

  $0.0015 \text{ mm}$

  
• How many cells will be present after 2 hours if the cell divides every 30 minutes?

  There will be 8 cells
• What are the main parts of animal and plant cells?

  They include the nucleus, cell membrane, and cytoplasm

  
• Which two parts in the plant leaf cell diagram are not found in an animal cell?

  Chloroplasts and cell wall

  
• Why do human skin cells need to divide?

  To replace dead or damaged cells
• Where may human stem cells come from?

  From embryos
• What conditions can human stem cells be used to treat?

  Conditions like cystic fibrosis
• If the scale bar in the muscle cell figure represents 0.1 mm, how do you calculate the magnification?

  Measure the scale bar and divide the measured length by 0.1 mm
• What is the function of mitochondria?

  To produce energy through respiration
• What is the function of a ribosome?

  To synthesize proteins
• Why can't ribosomes be seen through a light microscope?

  Because they are too small
• What is the name of the type of cell division for body cells?

  Mitosis
• What type of microscope is needed to see ribosomes and mitochondria?

  A transmission electron microscope
• What is the advantage of using a transmission electron microscope?

  It provides higher magnification
• What is the diameter of a bacterial cell if a red blood cell is 8 µm and the bacterial cell is 40 times smaller?

  0.2 µm
• What type of microscope was used to create the image of the cress plant root?

  A light microscope
• If the magnification of the cress root is × 200, how do you calculate the real length of the root hair?

  Divide the measured length by 200 and convert to µm
• How is the root hair cell adapted to take up water from the soil?

  It has a large surface area for absorption
• Why is the mean rate of water uptake higher on a hot day than on a cold day?

  Because evaporation increases on hot days
• Why do root hair cells contain mitochondria?

  To provide energy for active transport of minerals
• What are the key differences between prokaryotic and eukaryotic cells?

  • Prokaryotic cells lack a nucleus
  • Eukaryotic cells have a nucleus
  • Prokaryotic cells may contain plasmids
  • Eukaryotic cells have membrane-bound organelles
• What are the main functions of the parts of a plant cell?

  • Cell wall: Provides structure
  • Chloroplasts: Site of photosynthesis
  • Vacuole: Stores nutrients and waste products

  
• What are the main functions of the parts of an animal cell?

  • Nucleus: Stores genetic information
  • Mitochondria: Produces energy
  • Ribosomes: Synthesizes proteins