Human Health And Disease

Step 1: Analyse fasting blood glucose (FBS).
The normal fasting blood glucose level lies between 70–100 mg/dL. The given value is 90 mg/dL, which falls within the normal range.
Step 2: Answer part (a).
Yes, the fasting blood glucose value is normal.
Step 3: Analyse HbA1c value.
HbA1c represents the average blood glucose level over the past 2–3 months. A normal HbA1c value is usually below 5.7%. Values between 5.7%–6.4% indicate prediabetes, and values 6.5% or above indicate diabetes. The given value is 6.7%.
Step 4: Answer part (b).
No, the HbA1c value is not normal because it is above 6.5%, indicating diabetic condition.
Step 5: Suggest lifestyle habits.
To maintain normal blood glucose levels, the following habits should be followed:
- Regular physical exercise
- Balanced diet with low sugar and controlled carbohydrate intake
Step 6: Answer part (c).
Two lifestyle habits are regular exercise and healthy balanced diet.

Step 1: Identify the disease.
The presence of sickle-shaped red blood cells indicates that the patient is suffering from sickle cell anaemia, a genetic blood disorder.
Step 2: Cause of the disease.
This disease is caused by a mutation in the gene responsible for haemoglobin formation. The normal haemoglobin (HbA) is replaced by abnormal haemoglobin (HbS), which causes red blood cells to become rigid and sickle-shaped.
Step 3: Answer part (a).
Thus, the reason for this disease is a genetic mutation in haemoglobin leading to formation of abnormal HbS.
Step 4: Effects of this defect on the body.
Due to the abnormal shape, red blood cells lose their flexibility and may block blood vessels. This leads to:
- Reduced oxygen supply to tissues
- Pain and swelling due to blocked capillaries
- Damage to organs over time
- Shortened lifespan of red blood cells causing anaemia
Step 5: Answer part (b).
Therefore, this defect affects the body by causing poor oxygen transport, blockage of blood vessels, organ damage, and anaemia.

Step 1: Understanding the illustration.
The diagram shows normal cells gradually changing into abnormal cells and then forming a mass of irregular, uncontrolled cells. This indicates uncontrolled cell division.
Step 2: Identification of the defect.
The defect shown is cancer. It is characterized by uncontrolled growth and division of cells leading to tumor formation.
Step 3: Reasons for abnormal cell formation.
Abnormal cells are formed due to mutations in genes that control cell division. These mutations may be caused by carcinogens such as tobacco, radiation, harmful chemicals, or viral infections.
Step 4: Treatment measures.
Two common treatment measures are:
- Chemotherapy: Use of drugs to destroy cancer cells.
- Radiotherapy: Use of high-energy radiation to kill cancer cells.
Step 5: Conclusion.
Thus, cancer arises due to uncontrolled cell division, and it can be treated using methods like chemotherapy and radiotherapy.

Step 1: Identify the initiating enzyme.
When a wound occurs, the clotting process begins with the activation of an enzyme called thrombin.
Step 2: Understand the precursor activation.
Thrombin is formed from its inactive precursor prothrombin in the presence of clotting factors such as calcium ions and thromboplastin released from damaged tissues.
Step 3: Role of thrombin in clotting.
Thrombin plays a crucial role by converting the soluble plasma protein fibrinogen into insoluble fibrin threads.
Step 4: Formation of clot.
These fibrin threads form a mesh-like network that traps blood cells such as red blood cells and platelets, leading to the formation of a blood clot.
Step 5: Final outcome.
The clot seals the wound, preventing further blood loss and protecting the body from infection.

Step 1: Identify the target of antibiotics.
Antibiotics are medicines that specifically act against bacterial infections. They either kill bacteria or inhibit their growth by targeting bacterial cell structures or metabolic pathways.
Step 2: Answer part (a).
The type of pathogen that can be destroyed using antibiotics is bacteria. Antibiotics are not effective against viruses or other non-bacterial pathogens.
Step 3: Understanding incomplete treatment.
When a patient starts taking antibiotics, the weaker bacteria are killed first, leading to improvement in symptoms. However, some stronger bacteria may still survive in the body.
Step 4: Explain the major concern.
If the antibiotic course is stopped too early, the remaining bacteria can multiply again. These surviving bacteria may develop resistance to the antibiotic, making future infections harder to treat.
Step 5: Conclusion.
Therefore, completing the full course of antibiotics is essential to completely eliminate the infection and prevent antibiotic resistance.