A level Bio 3.4 Mass transport in Animals Part II

Explain why both the heart and arteries are described as organs. (1)

contains more than one tissue/type of cell (1)

Which of blood vessels A to E contains blood at the lowest pressure? (1)

E (1)

hepatic vein has traveled through two full networks of capillaries,

Elastic tissue in the walls of blood vessel A helps to even out the pressure of blood through this vessel. Explain how. (2)

(Elastic tissue) stretches when pressure in high (1)

Springs back/recoils /returns to normal when pressure is low (1)

Erythropoietin (EPO) is a substance produced in the body. It increases the production of red blood cells. Synthetic EPO is made artificially. It is used to treat patients who have a form of anaemia in which there is a reduced number of red blood cells. Scientists investigated the effect of synthetic EPO on volunteers with this form of anaemia.

•        The scientists injected synthetic EPO in a salt solution into patients in the experimental groups. They also set up control groups.

•        They gave the different experimental groups different doses of synthetic EPO and different lengths of treatment.

•        At the beginning and end of the treatment, the scientists measured each patient’s haemoglobin concentration. From these measurements, they calculated the mean increase in haemoglobin concentration.

Some of the results are shown in the table.

 

	Number of volunteers	Length of treatment / weeks	Dose of synthetic EPO / units per kilogram per week	Mean increase in haemoglobin concentration / arbitrary units
	58	8	85	19.0
	18	8	170	26.0
	40	12	150	12.5
	82	12	450	34.2
	46	24	120	23.0
	53	24	240	31.0

The scientists measured the dose of synthetic EPO per kilogram per week.

Explain why they measured the dose per unit mass and per unit time. (2)

Allows comparison to be made (1)

Different masses/weights (of volunteers) (1)

Erythropoietin (EPO) is a substance produced in the body. It increases the production of red blood cells. Synthetic EPO is made artificially. It is used to treat patients who have a form of anaemia in which there is a reduced number of red blood cells. Scientists investigated the effect of synthetic EPO on volunteers with this form of anaemia.

Some of the results are shown in the table.

 

	Number of volunteers	Length of treatment / weeks	Dose of synthetic EPO / units per kilogram per week	Mean increase in haemoglobin concentration / arbitrary units
	58	8	85	19.0
	18	8	170	26.0
	40	12	150	12.5
	82	12	450	34.2
	46	24	120	23.0
	53	24	240	31.0

Explain how the information that the scientists collected might be useful in treating patients with anaemia (2)

To determine (most effective) dose/length of treatment (1)

Investigate long term effect/toxicity/side effects

Erythropoietin (EPO) is a substance produced in the body. It increases the production of red blood cells. Synthetic EPO is made artificially. It is used to treat patients who have a form of anaemia in which there is a reduced number of red blood cells.

Some athletes have used synthetic EPO as a performance enhancer. Explain how synthetic EPO may improve performance in long-distance events. (4)

More haemoglobin/more red blood cells (1)

(More) oxygen can be absorbed/transproted to respiring tissues/cells (1)

More energy released/more ATP for muscle contraction (1)

Delays anaerobic respiration (1)

Erythropoietin (EPO) is a substance produced in the body. It increases the production of red blood cells. Synthetic EPO is made artificially. It is used to treat patients who have a form of anaemia in which there is a reduced number of red blood cells.

Some athletes have used synthetic EPO as a performance enhancer.

Athletes may be tested to see if the concentration of EPO in their blood is above normal. Suggest how scientists determine the normal concentration of EPO in blood. (2)

Large sample / wide range (of individuals tested) (1)

Random sampling

Erythropoietin (EPO) is a substance produced in the body. It increases the production of red blood cells. Synthetic EPO is made artificially. It is used to treat patients who have a form of anaemia in which there is a reduced number of red blood cells.

Synthetic EPO can increase blood pressure. Suggest why. (1)

Blood is thicker(1)