Master GCSE Biology

MS1:

- The thin, flexible boundary surrounding the cytoplasm (1)

- Controls what enters and leaves the cell (1)

MS2:

- Large number of cristae (folded membranes) which provide a large surface area for ATP production (1)

- Matrix contains enzymes for respiration (1)

MS3:

- Prokaryotes (1 mark)

- Lack a nucleus and membrane-bound organelles (1)

- E.g., bacteria

- Eukaryotes (1 mark)

- Have a nucleus and membrane-bound organelles (1)

- E.g., animal and plant cells

MS4:

- Cytoplasm (1)

MS5:

- Steps: (3 marks)

- Sterilizing equipment (e.g., autoclaving)

- Working in a sterile environment (e.g., laminar flow cabinet)

- Using sterile materials (e.g., pipettes, culture media)

- Bonus mark: (1 mark)

- Explains the purpose of each step (e.g., killing microorganisms, preventing airborne contamination, reducing risk of bacterial growth)

MS6:

- Concentration gradient: (1 mark)

- Osmosis occurs from a higher concentration to a lower concentration

- Hypotonic solution: (1 mark)

- Cell takes in water and swells

- Hypertonic solution: (1 mark)

- Cell loses water and shrinks

MS7:

- Binary fission: (1 mark)

- Process of asexual reproduction in which a parent cell divides into two identical daughter cells

- Example: (1 mark)

- Bacteria (e.g., E. coli)

MS8:

- Step 1: (1 mark)

- Golgi apparatus modifies proteins by adding carbohydrates

- Step 2: (1 mark)

- Vesicles formed from Golgi apparatus package the modified proteins

- Step 3: (1 mark)

- Vesicles transport packaged proteins to cell membrane

- Step 4: (1 mark)

- Vesicles fuse with cell membrane and release proteins outside the cell

MS9:

- Resolution: (1 mark)

- Ability to distinguish between two closely spaced objects

- Magnification: (1 mark)

- Makes objects appear larger

- Relationship: (1 mark)

- Higher resolution provides sharper images, while higher magnification increases the size of the image

MS10:

- Ribosomes (1)

- Found on endoplasmic reticulum (attached ribosomes) and free in the cytoplasm (free ribosomes) (1)