
Human blood smear X200	Turtle's blood smear X200

Information about red blood cells :

1. Mature red blood cells in human blood do not have nucleus.

2. The significance of the absence of nucleus is that the red blood cells can have more space to hold more haemoglobin.

3. There is a nucleus in the red blood cell in turtle's blood.

4. The human red blood cells are biconcave disc shaped. As a result, the central part of the cells seems to be lighter in colour when they are observed in the microscope. More light can pass through the central part.

5. The significance of having a biconcave shape is to increase the surface area for oxygen uptake and release.

6. The red blood cells are flattened disc shaped. This can allow more haemoglobin to uptake or release oxygen readily. The diffusion distance is shortened.

7. The red blood cells hold a lot of haemoglobin. Haemoglobin is a kind of protein which is red in colour. This haemoglobin in turn makes red blood cells red. The presence of red blood cells in turn makes the blood red.