Year 6 Science: Blood and its parts
Part of the Year 6 Science the circulatory system and transport chapter. Chapter overview · whole chapter on one page
Blood and its parts
Blood is a liquid tissue that is made of four parts, which all do different jobs.
The plasma is the liquid that carries everything else. It carries dissolved nutrients, waste and hormones. The red blood cells carry oxygen. The white blood cells help to fight infection. The platelets are small pieces that help the blood to clot, which means to form a plug over a damaged blood vessel.
The table gives the job of each part.
| Part of blood | Job |
|---|---|
| Plasma | the liquid part of blood; carries the other parts, and dissolved nutrients, waste and hormones |
| Red blood cells | carry oxygen around the body |
| White blood cells | help to fight infection and disease |
| Platelets | small pieces that help the blood to clot when a blood vessel is damaged |
Key ideas
- Plasma is the liquid part of blood, and it carries the other parts.
- Red blood cells carry oxygen around the body.
- White blood cells help to fight infection.
- Platelets help the blood to clot when a blood vessel is damaged.
Method. Find the part with the job of carrying oxygen.
- Read the table. The red blood cells carry oxygen around the body.carry oxygen
- Write the name. So the part is the red blood cells.red blood cells
- Write the answer. red blood cells
Check. Red blood cells contain a substance that holds oxygen. ✓
Method. Find the part that helps the blood to clot.
- Read the table. The platelets help the blood to clot.clot
- Write the name. So the part is platelets.platelets
- Write the answer. platelets
Check. Platelets are small pieces that form a plug. ✓
Method. Find the liquid part.
- Read the table. The plasma is the liquid part, and it carries the other parts.plasma
- Write the word. So the liquid part is plasma.plasma
- Write the answer. plasma
Check. Plasma carries nutrients, waste and hormones. ✓
Watch out
Watch out: red blood cells carry oxygen; they do not fight infection. White blood cells help to fight infection.
Exam tip
Exam tip. Link each part of the blood to its job: red for oxygen, white for infection, platelets for clotting, plasma for carrying.
Try it (with your teacher, or a grown-up at home). Look at a small cut or scratch on a grown-up's skin, if they agree, or look at a picture of a scab. Talk about how blood clots. Wash your hands afterwards, and do not touch anyone else's blood.
Exercise 3C Blood and its parts
Method. Read the table in section 3.3.
- Read the table. The plasma is the liquid part of the blood.liquid
- Write the word. So the word is plasma.plasma
- Write the answer. plasma
Check. The other parts float in the plasma. ✓
Method. Read the job of each cell.
- Read the job. Red blood cells carry oxygen around the body.oxygen
- Write the words. So the cells are red blood cells.red blood cells
- Write the answer. red blood cells
Check. Red blood cells are the most common cells in blood. ✓
Method. Read the job of each cell.
- Read the job. White blood cells help to fight infection and disease.infection
- Write the words. So the cells are white blood cells.white blood cells
- Write the answer. white blood cells
Check. White blood cells are part of the immune system. ✓
Method. Read the job of platelets.
- Read the job. Platelets help the blood to clot when a vessel is damaged.clot
- Write the word. So the word is platelets.platelets
- Write the answer. platelets
Check. Platelets help form a plug. ✓
Method. Count the rows in the table.
- Count. The table has plasma, red blood cells, white blood cells and platelets.four rows
- Write the answer. So there are four parts.4
- Write the answer. 4
Check. Each part has its own job. ✓
Method. Read the job of plasma.
- Read the job. Plasma carries dissolved nutrients, waste and hormones.nutrients
- Write the word. So the part is plasma.plasma
- Write the answer. plasma
Check. Plasma is the liquid that carries things. ✓
Method. Read the job of white blood cells.
- Read the job. White blood cells help to fight infection.fight infection
- Write one word. The key word is infection.infection
- Write the answer. infection
Check. Fighting infection protects the body. ✓
Method. Check the job of red blood cells.
- Read the table. Red blood cells carry oxygen, and white blood cells fight infection.carry oxygen
- Decide. So Ali is not right.no
- Write the answer. no
Check. Each part of the blood has its own job. ✓
Method. Read the job of plasma.
- Read the job. Plasma carries dissolved nutrients, waste and hormones.nutrients, waste, hormones
- Choose two. Any two of these are correct.two
- Write the answer. Accept any two of: nutrients, waste, hormones, carbon dioxide.
Check. Plasma is the transport liquid. ✓
Method. Think about clotting.
- Think about the job. The part that helps the blood clot is the platelets.clot
- Write the word. So a shortage of platelets could stop the blood clotting.platelets
- Write the answer. platelets
Check. Platelets help the blood to form a plug. ✓
Method. Think about the job of red blood cells.
- Think about oxygen. Red blood cells carry oxygen.oxygen
- Think about the body. Less oxygen reaches the body cells, so the body has less energy.less energy
- Write the answer. Accept any sentence that says fewer red blood cells means less oxygen is carried to the body cells, so the person feels tired.
Check. The body needs oxygen to release energy from food. ✓
Method. Think about the job.
- Think about infection. Germs can cause infection.germs
- Think about the cells. White blood cells help to fight these germs.fight germs
- Write the answer. Accept any sentence that says white blood cells help to fight germs that cause infection.
Check. White blood cells protect the body. ✓
Method. Think about the parts of the blood.
- Think about the liquid. The plasma is a liquid.plasma
- Think about the cells. The red and white cells and platelets float in the plasma and are carried round the body.carried
- Write the answer. Accept any sentence that says plasma is the liquid, and the cells and platelets float in it and are carried around the body.
Check. The plasma is the transport system for the cells. ✓