Fill-in-the-blank table designed to help students identify and describe the four main components of human blood.

Here is the completed table and the solutions to the questions based on the image provided.

Part 1: The Blood Table

Here are the details to fill in the missing columns for the four components of blood shown in the pictures.

| Component | Description | Function | Adaptations | Diseases |
| :--- | :--- | :--- | :--- | :--- |
| Red Blood Cell (Erythrocyte) | A biconcave disc shape (dished in the middle) with no nucleus. Filled with red haemoglobin. | Transports oxygen from the lungs to the rest of the body. | 1. Biconcave shape: Increases surface area for faster gas exchange.<br>2. No nucleus: Makes more room for haemoglobin.<br>3. Small size: Can squeeze through tiny capillaries. | Anaemia: Too few red blood cells or not enough haemoglobin, causing tiredness. |
| White Blood Cell (Leukocyte) | Larger than red blood cells, irregular shape, contains a nucleus. | Defends the body against pathogens (bacteria and viruses). | 1. Nucleus: Contains DNA to make proteins.<br>2. Lysosomes: Contains enzymes to digest bacteria.<br>3. Flexible membrane: Can change shape to engulf bacteria. | Leukemia: Cancer of the blood forming too many abnormal white blood cells. |
| Platelets (Thrombocytes) | Tiny, irregular cell fragments (not full cells). | Help blood to clot at wounds to stop bleeding and prevent infection. | They are small and sticky, allowing them to clump together quickly at the site of a cut. | Haemophilia: A genetic disorder where blood doesn't clot properly. |
| Plasma | A pale yellow liquid that makes up the majority of blood volume. | Transports everything around the body (red/white cells, platelets, nutrients, hormones, waste). | It is mostly water, which is an excellent solvent for carrying dissolved substances. | Dehydration: Loss of water from plasma makes blood thicker and harder to pump. |

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Part 2: Questions

1. Suggest what the symptoms of anaemia might be?
* Reasoning: Anaemia means the blood cannot carry enough oxygen. Oxygen is needed for respiration, which releases energy for the body.
* Answer: Common symptoms include feeling very tired (fatigue), being short of breath, feeling dizzy, and having pale skin.

2. A normal white cell count is around 8500 cells per microliter. An AIDS sufferer has 680. Calculate the percentage decrease.
* Step 1: Find the difference between the normal count and the patient's count.
$$8500 - 680 = 7820$$
* Step 2: Divide the difference by the original (normal) number.
$$7820 \div 8500 = 0.92$$
* Step 3: Multiply by 100 to get the percentage.
$$0.92 \times 100 = 92\%$$
* Answer: 92%

3. Explain why a white blood cell contains lots of ribosomes.
* Reasoning: Ribosomes are the parts of the cell responsible for making proteins. White blood cells fight infection by producing antibodies (which are proteins) and enzymes to destroy bacteria.
* Answer: White blood cells need to produce large amounts of proteins (specifically antibodies and enzymes) to fight off infections. Ribosomes are the "factories" where proteins are made, so they need many of them to do this job effectively.

4. The average lifespan of a red blood cell is 120 days. What makes new cells and where is it found?
* Answer: New red blood cells are made in the bone marrow.

Final Answer:
Table Answers:
1. Red Blood Cell: Function: Transport oxygen. Adaptation: Biconcave shape for surface area / No nucleus for space. Disease: Anaemia.
2. White Blood Cell: Function: Fight infection. Adaptation: Nucleus / Can change shape. Disease: Leukemia.
3. Platelets: Function: Clotting. Adaptation: Sticky / Small. Disease: Haemophilia.
4. Plasma: Function: Transport. Adaptation: Liquid solvent. Disease: Dehydration.

Question Answers:
1. Tiredness, shortness of breath, dizziness, pale skin.
2. 92%
3. To make proteins (antibodies/enzymes) to fight infection.
4. Bone marrow.