Master GCSE Biology

MS1:

- A group of similar cells working together to perform a specific function (2)

MS2:

- Arteries carry blood away from the heart (1)

- Arteries have thicker muscular walls than veins (1)

- Arteries carry oxygenated blood except pulmonary artery (1)

MS3:

- Red blood cells have a biconcave shape, providing a large surface area for diffusion of gases (1)

- They contain haemoglobin, which binds to oxygen (1)

- They are flexible and can squeeze through narrow capillaries (1)

- Lack of a nucleus increases the volume of the cell available for haemoglobin (1)

MS4:

- Platelets (1)

MS5:

- Plaque builds up in arteries, narrowing the lumen (1)

- This reduces blood flow and can lead to heart attacks and strokes (1)

- Treatment: stent to widen the artery (1)

MS6:

- Bile emulsifies fats (1)

- Breaks large fat droplets into smaller ones (1)

- Increasing surface area of fat for enzymes to work (1)

MS7:

- Diaphragm: muscle that contracts to draw air into lungs during breathing (1)

- Organ example: heart (1)

MS8:

- Xylem vessels are wide and have no end walls for easy water transport (1)

- Lignin strengthens xylem, prevents collapse (1)

- Phloem has companion cells that provide energy for active transport of sugars (1)

MS9:

- Atria receive blood from veins (1)

- Ventricles pump blood out of the heart to arteries (1)

- Valves prevent backflow of blood (1)

MS10:

- Evaporation of water from plant leaves (1)

- Occurs through stomata (1)