Question 1: Define plasma and describe its main functions in the blood.

Answer: Plasma is the straw-coloured liquid component of blood that transports nutrients, hormones, waste products, and maintains blood pressure and temperature.

Question 2: What are red blood cells (erythrocytes) and how do their structure aid in their function?

Answer: Red blood cells are biconcave, disc-shaped cells containing haemoglobin, which allows efficient oxygen transport by increasing surface area and flexibility for movement through capillaries.

Question 3: Explain the role of haemoglobin in blood.

Answer: Haemoglobin is a protein in red blood cells that binds to oxygen in the lungs and releases it in tissues, enabling oxygen transport throughout the body.

Question 4: Calculate the volume of haemoglobin in a 70 kg adult male if the average haemoglobin concentration is 150 g/L, and the total blood volume is approximately 5.6 litres.

Answer: Volume of haemoglobin = concentration (g/L) × blood volume (L) = 150 g/L × 5.6 L = 840 g

Question 5: Describe the process and safety precautions involved in collecting a blood sample for analysis.

Answer: Blood samples are collected using sterile equipment, usually via venipuncture. Precautions include wearing gloves, sterilising the site, and disposing of sharps safely to prevent infection and injury.

Question 6: Identify the main components of blood plasma and their functions.

Answer: Main components include water (transport medium), plasma proteins (e.g., albumin, antibodies), hormones, nutrients, waste products, and ions, all of which maintain homeostasis and transport substances.

Question 7: Multiple Choice: Which component of blood is primarily responsible for fighting infections?

Answer: White blood cells

Question 8: Fill in the blank: Platelets are fragments of cells that are essential for the process of __________ and blood clotting.

Answer: haemostasis

Question 9: Discuss how blood composition varies between individuals and the implications for blood transfusions.

Answer: Blood composition can vary due to factors such as age, sex, health status, and genetics, affecting haemoglobin levels and blood cell counts. These variations are critical in blood transfusions, as mismatched blood types can cause serious reactions, so compatibility testing is essential.

Question 10: Apply your understanding of blood composition to explain how a deficiency in red blood cells can lead to anaemia.

Answer: A deficiency in red blood cells reduces haemoglobin levels, impairing oxygen transport. This causes symptoms such as fatigue, weakness, and shortness of breath, characteristic of anaemia. Causes include nutritional deficiencies, blood loss, or bone marrow problems.