Option D: Human physiology (Additional higher level topics)

Explain how steroid and peptide hormones exert their effect.

Explain how steroid and peptide hormones exert their effect.

Using the graph, explain the Bohr shift.

Using the graph, explain the Bohr shift.

Using the graph, explain the Bohr shift.

The action of thyroxin is similar to steroid hormones. Describe the action of steroid hormones.

The action of thyroxin is similar to steroid hormones. Describe the action of steroid hormones.

The action of thyroxin is similar to steroid hormones. Describe the action of steroid hormones.

The World Health Organization recommends that the iodine intake should be supplemented in pregnant women due to their increased requirements. Outline the need for iodine supplementation.

The World Health Organization recommends that the iodine intake should be supplemented in pregnant women due to their increased requirements. Outline the need for iodine supplementation.

The World Health Organization recommends that the iodine intake should be supplemented in pregnant women due to their increased requirements. Outline the need for iodine supplementation.

Discuss high altitude training for athletes.

Discuss high altitude training for athletes.

Describe the mode of action of steroid hormones.

Describe the mode of action of steroid hormones.

Describe the mode of action of steroid hormones.

Explain how an increase in cell respiration in a tissue causes increased release of oxygen by hemoglobin in the tissue.

Explain how an increase in cell respiration in a tissue causes increased release of oxygen by hemoglobin in the tissue.

Compare and contrast steroid and peptide hormone action.

Compare and contrast steroid and peptide hormone action.

Explain how physical exercise affects the affinity of hemoglobin for oxygen. You could supplement your explanation with a labeled diagram. 

Explain how physical exercise affects the affinity of hemoglobin for oxygen. You could supplement your explanation with a labeled diagram. 

Explain how physical exercise affects the affinity of hemoglobin for oxygen. You could supplement your explanation with a labeled diagram. 

The electron micrograph shows a section through an alveolus showing blood in a capillary.

[Source: © International Baccalaureate Organization 2019]

Identify the cells found at X and Y.

X: 

Y:

The electron micrograph shows a section through an alveolus showing blood in a capillary.

[Source: © International Baccalaureate Organization 2019]

Identify the cells found at X and Y.

X: 

Y:

The electron micrograph shows a section through an alveolus showing blood in a capillary.

[Source: © International Baccalaureate Organization 2019]

Identify the cells found at X and Y.

X: 

Y:

Discuss the significance of the oxygen dissociation curves for adult hemoglobin and fetal hemoglobin.

Discuss the significance of the oxygen dissociation curves for adult hemoglobin and fetal hemoglobin.

Distinguish between the mode of action of steroid hormones and peptide hormones.

Distinguish between the mode of action of steroid hormones and peptide hormones.

Distinguish between the mode of action of steroid hormones and peptide hormones.

Thyroxin is a hormone produced in the thyroid gland. State one function of thyroxin.

Thyroxin is a hormone produced in the thyroid gland. State one function of thyroxin.

Thyroxin is a hormone produced in the thyroid gland. State one function of thyroxin.

State two modes of transport of carbon dioxide in blood. 

1.

2. 

State two modes of transport of carbon dioxide in blood. 

1.

2. 

State two modes of transport of carbon dioxide in blood. 

1.

2. 

Describe what happens to the hemoglobin from old or damaged red blood cells that are broken down.

Describe what happens to the hemoglobin from old or damaged red blood cells that are broken down.

Describe what happens to the hemoglobin from old or damaged red blood cells that are broken down.

Compare and contrast the effect on men and women of an increase in serum cholesterol.

Compare and contrast the effect on men and women of an increase in serum cholesterol.

Compare and contrast the effect on men and women of an increase in serum cholesterol.

Scientific evidence demonstrates that reducing total cardiovascular risk results in the prevention of coronary heart disease. The chart shows attributable deaths in global population (in thousands) due to six leading cardiovascular risk factors.

_{[Source: Mendis, Shanthi, Puska, Pekka, Norrving, B, World Health Organization, World Heart Federation et al. (2011). Global
atlas on cardiovascular disease prevention and control / edited by: Shanthi Mendis ... [et al.]. World Health Organization.
Graph of attributable deaths due to selected risk factors.]}

Describe how two named risk factors shown in the graph can lead to coronary heart disease.

1.

2.

Scientific evidence demonstrates that reducing total cardiovascular risk results in the prevention of coronary heart disease. The chart shows attributable deaths in global population (in thousands) due to six leading cardiovascular risk factors.

_{[Source: Mendis, Shanthi, Puska, Pekka, Norrving, B, World Health Organization, World Heart Federation et al. (2011). Global
atlas on cardiovascular disease prevention and control / edited by: Shanthi Mendis ... [et al.]. World Health Organization.
Graph of attributable deaths due to selected risk factors.]}

Describe how two named risk factors shown in the graph can lead to coronary heart disease.

1.

2.

Explain how changes to the cell cycle can result in tumour formation.

Explain how changes to the cell cycle can result in tumour formation.

Explain how changes to the cell cycle can result in tumour formation.

Sorbitol is oxidized to sorbose by the enzyme sorbitol dehydrogenase. The conversion rate was measured by monitoring sorbose concentrations. The graph shows the activity of sorbitol dehydrogenase at different pH values.

_{[Source: Tae-Su Kim, Gao Hui, Jinglin Li, Vipin C. Kalia, Karthikeyan Muthusamy,
Jae Kyung Sohng, In-Won Kim and Jung-Kul Lee, 2019.
Overcoming NADPH product inhibition improves D-sorbitol conversion to L-sorbose.
Scientific Reports, 9, p. 815. https://doi.org/10.1038/s41598-018-37401-0. Open Access.]}

What can be deduced from these results?

A.  There is no conversion of sorbitol to sorbose at a pH of 10.

B.  At least 10 % of the product is transformed to substrate at a pH of 9.

C.  The pH affects the rate of activity of the enzyme sorbitol dehydrogenase.

D.  The amount of sorbose produced is not affected by the substrate concentration.

Sorbitol is oxidized to sorbose by the enzyme sorbitol dehydrogenase. The conversion rate was measured by monitoring sorbose concentrations. The graph shows the activity of sorbitol dehydrogenase at different pH values.

_{[Source: Tae-Su Kim, Gao Hui, Jinglin Li, Vipin C. Kalia, Karthikeyan Muthusamy,
Jae Kyung Sohng, In-Won Kim and Jung-Kul Lee, 2019.
Overcoming NADPH product inhibition improves D-sorbitol conversion to L-sorbose.
Scientific Reports, 9, p. 815. https://doi.org/10.1038/s41598-018-37401-0. Open Access.]}

What can be deduced from these results?

A.  There is no conversion of sorbitol to sorbose at a pH of 10.

B.  At least 10 % of the product is transformed to substrate at a pH of 9.

C.  The pH affects the rate of activity of the enzyme sorbitol dehydrogenase.

D.  The amount of sorbose produced is not affected by the substrate concentration.

The light micrograph shows the structure of blood vessels in a muscle.

_{[Source: Calvo, J.L., n.d. [image online] Available at: https://www.shutterstock.com/image-photo/muscular-artery-veinnervebundles-
surrounded-785176687 [Accessed 12 January 2022].]}

Which blood vessel is shown by X?

A.  A vein

B.  An artery

C.  An arteriole

D.  A capillary

The light micrograph shows the structure of blood vessels in a muscle.

_{[Source: Calvo, J.L., n.d. [image online] Available at: https://www.shutterstock.com/image-photo/muscular-artery-veinnervebundles-
surrounded-785176687 [Accessed 12 January 2022].]}

Which blood vessel is shown by X?

A.  A vein

B.  An artery

C.  An arteriole

D.  A capillary

Annotate the diagram by adding arrows to show how deoxygenated blood enters the heart.

Annotate the diagram by adding arrows to show how deoxygenated blood enters the heart.

Annotate the diagram by adding arrows to show how deoxygenated blood enters the heart.