Question 1: Blood is composed of various components, including cells and plasma, which are essential for transporting substances and maintaining homeostasis. Understanding the proportions and functions of these components can help in environmental health assessments and medical diagnoses.

Answer: Blood consists mainly of red blood cells, white blood cells, platelets, and plasma; each has specific functions in oxygen transport, immune response, clotting, and transport of nutrients and waste.

Question 1: Define plasma and explain its role in blood.

Answer: Plasma is the liquid component of blood that transports nutrients, hormones, waste products, and maintains blood pressure and pH balance.

Question 2: Describe how red blood cells are specialised for their function.

Answer: Red blood cells contain haemoglobin, are biconcave in shape to increase surface area, and lack nuclei to maximise space for oxygen transport.

Question 1: Calculate the volume of plasma in a 70 kg adult with a total blood volume of 5 litres, given that plasma makes up approximately 55% of blood volume. Express your answer in litres.

Answer: 0.55 x 5 = 2.75 litres

Question 2: A sample of blood contains 5 million red blood cells per microlitre. How many red blood cells are present in 3 millilitres of blood? (1 millilitre = 1,000,000 microlitres)

Answer: 5,000,000 x 3,000,000 = 1.5 x 10^13

Question 1: Identify three variables that should be controlled during a blood analysis experiment and explain why.

Answer: Variables include temperature, pH, and sample volume; controlling these ensures accurate and consistent results.

Question 2: List two safety precautions that should be observed when handling blood samples in the laboratory.

Answer: Wearing gloves and disposing of samples in biohazard containers to prevent infection.

Question 1: A study reports that in a polluted environment, the average haemoglobin level in young adults drops from 15 g/100 mL of blood to 12 g/100 mL. Discuss possible environmental factors that could contribute to this decrease.

Answer: Environmental pollutants such as heavy metals, sulphur compounds, or lead can interfere with red blood cell production or haemoglobin synthesis, leading to anaemia or reduced oxygen transport capacity.

Question 1: Explain how the composition of blood makes it suitable for its role in transporting substances, and discuss the importance of maintaining blood health in environmental contexts.

Answer: Blood's composition, including plasma for transport and cells like red and white blood cells, enables efficient delivery of oxygen, nutrients, and removal of waste. Maintaining blood health is crucial as environmental pollutants can impair blood function, leading to health issues. Monitoring blood composition can also help assess environmental impacts on human health.

Question 1: Describe how understanding blood composition can assist in developing environmental health policies or technologies, such as blood testing for pollution exposure.

Answer: Understanding blood components allows for the development of diagnostic tests to detect pollutant exposure, enabling early intervention. It also helps establish safe environmental standards by correlating pollutant levels with blood health indicators.