Figure 19 shows a diagram of a red blood cell from a turtle and a diagram of a red blood cell from a human. (i) These cells are animal cells. Animal cells do not have A cytoplasm B a cell wall C mitochondria (ii) The actual length of the red blood cell from a turtle is 20.5µm. Calculate the length of the magnified image of the red blood cell of the turtle when magnified 400x. (iii) The width of the human red blood cell, when magnified 400x, is 3.08 mm. Calculate the actual width of the cell and show your answer in standard form. Red blood cells are carried in veins and arteries. Figure 20 shows the equipment used to measure the elasticity of an artery. (i) Describe a method you could use to see how much the ring of tissue from an artery could stretch before it no longer returned to its original size. (ii) Give one safety precaution you need to take when handling animal tissue such as blood vessels. Figure 21 shows the circulatory system of a frog. Explain why the circulatory system of a frog is less efficient at carrying oxygen to the tissues than the circulatory system of a human.

GCSE Edexcel Biology Circulatory system- blood vessels: Figure 19 shows a diagram of a r

Figure 19 shows a diagram of a red blood cell from a turtle and a diagram of a red blood cell from a human - Edexcel - GCSE Biology - Question 8 - 2018 - Paper 1

Question 8

Figure 19 shows a diagram of a red blood cell from a turtle and a diagram of a red blood cell from a human. (i) These cells are animal cells. Animal cells do not ha... show full transcript

Worked Solution & Example Answer:Figure 19 shows a diagram of a red blood cell from a turtle and a diagram of a red blood cell from a human - Edexcel - GCSE Biology - Question 8 - 2018 - Paper 1

Step 1

i) These cells are animal cells. Animal cells do not have

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Answer

The answer is B, a cell wall, as animal cells lack this structural feature which is present in plant cells.

Step 2

ii) The actual length of the red blood cell from a turtle is 20.5µm. Calculate the length of the magnified image of the red blood cell of the turtle when magnified 400x.

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Answer

To calculate the length of the magnified image:

$ext{Length of magnified image} = ext{Actual length} imes ext{magnification}$

Thus, $ext{Length of magnified image} = 20.5 ext{µm} imes 400 = 8200 ext{µm}$

Therefore, the length of the magnified image is 8200 µm.

Step 3

iii) The width of the human red blood cell, when magnified 400x, is 3.08 mm. Calculate the actual width of the cell and show your answer in standard form.

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Answer

First, convert 3.08 mm to micrometers:

$3.08 ext{ mm} = 3080 ext{ µm}$

Next, use the formula:

$ext{Actual width} = rac{ ext{magnified width}}{ ext{magnification}}$

Thus, $ext{Actual width} = rac{3080 ext{ µm}}{400} = 7.7 ext{ µm}$

In standard form, this is represented as: $7.7 imes 10^0 ext{ µm}$ .

Step 4

i) Describe a method you could use to see how much the ring of tissue from an artery could stretch before it no longer returned to its original size.

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Answer

To measure the elasticity of the tissue:

Measure the initial length of the ring of tissue.
Gradually add weights using a mass carrier until the tissue stretches.
Measure the length after adding each weight.
Continue adding weights until the tissue no longer returns to its original length.
Record these lengths at each stage for analysis.

Step 5

ii) Give one safety precaution you need to take when handling animal tissue such as blood vessels.

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Answer

One safety precaution is to wear gloves to prevent contamination and protect yourself from exposure to potentially harmful substances.

Step 6

Explain why the circulatory system of a frog is less efficient at carrying oxygen to the tissues than the circulatory system of a human.

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Answer

The frog's circulatory system has only one ventricle and three chambers, whereas humans have two ventricles and four chambers. This setup in frogs allows for mixing of oxygenated and deoxygenated blood, resulting in less efficient oxygen transport to the tissues. In contrast, the human circulatory system effectively separates these two types of blood, ensuring more efficient oxygen delivery.

Figure 19 shows a diagram of a red blood cell from a turtle and a diagram of a red blood cell from a human - Edexcel - GCSE Biology - Question 8 - 2018 - Paper 1

Worked Solution & Example Answer:Figure 19 shows a diagram of a red blood cell from a turtle and a diagram of a red blood cell from a human - Edexcel - GCSE Biology - Question 8 - 2018 - Paper 1

i) These cells are animal cells. Animal cells do not have

ii) The actual length of the red blood cell from a turtle is 20.5µm. Calculate the length of the magnified image of the red blood cell of the turtle when magnified 400x.

iii) The width of the human red blood cell, when magnified 400x, is 3.08 mm. Calculate the actual width of the cell and show your answer in standard form.

i) Describe a method you could use to see how much the ring of tissue from an artery could stretch before it no longer returned to its original size.

ii) Give one safety precaution you need to take when handling animal tissue such as blood vessels.

Explain why the circulatory system of a frog is less efficient at carrying oxygen to the tissues than the circulatory system of a human.

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