Organisation

Define a tissue and an organ.

Use the human digestive system to explain the levels of organisation from cell to organ system.

Heart muscle cells contain many mitochondria and form cardiac muscle tissue. Explain how this example fits into the organisation of the whole human body.

State the products formed when protease digests protein and when lipase digests lipid.

Explain how bile increases the rate at which lipid is digested in the small intestine.

Plan an investigation that compares how quickly amylase removes starch under several pH conditions. Include the end point, rate processing and two control variables.

State where blood is pumped by the right ventricle and by the left ventricle.

Compare how an artery, a vein and a capillary are adapted to their functions.

A person's heart pumps $4.8\,\mathrm{dm^3}$ of blood in $60\,\mathrm{s}$. Calculate the mean blood-flow rate in $\mathrm{dm^3\,s^{-1}}$ and explain why the wall of the left ventricle is thicker than that of the right ventricle.

State two substances transported dissolved in blood plasma.

Explain three ways in which a red blood cell is adapted to transport oxygen.

A blood sample from an infected patient contains unusually many cells with nuclei, while another patient has a very low platelet count. Explain the likely function of the numerous nucleated cells and one consequence of the low platelet count.

Explain why narrowing of a coronary artery can damage heart muscle.

Compare the use of a stent with the use of statins to treat coronary heart disease.

A patient with severe heart failure could receive a donor-heart transplant or use an artificial heart while waiting. Evaluate these two options.

State what is meant by health.

Explain two ways in which one type of disease can increase the risk or severity of another health problem.

In one town, $80$ cases of a disease occur in a sample of $2000$ people. Calculate the incidence per $1000$ people. A second town reports $15$ cases per $1000$ people. Compare the incidences and state one feature needed for a valid comparison.

State two lifestyle risk factors for cardiovascular disease.

Explain why smoking is described as a risk factor for both lung cancer and cardiovascular disease, and why this does not mean every smoker develops either disease.

A study records lung disease in $24$ of $800$ smokers and $9$ of $900$ non-smokers. Calculate the percentage affected in each group, compare the risks and explain why these data alone do not prove that smoking caused every case.

Describe how cancer develops at the cellular level.

Compare benign and malignant tumours.

A person inherits a genetic variant associated with bowel cancer and also has a lifestyle risk factor for cancer. Explain why the person has an increased risk but cannot be predicted with certainty to develop a malignant tumour.

State two adaptations of palisade mesophyll tissue for photosynthesis.

Explain how epidermal, palisade mesophyll and spongy mesophyll tissues work together in a leaf.

A transverse leaf section shows tightly packed cells beneath the upper epidermis, loosely arranged cells with air spaces, and a vein. Explain the functions of these three regions and identify the two transport tissues expected in the vein.

State what xylem transports and what phloem transports in a plant.

Explain how a rise in temperature, faster air movement, lower humidity and greater light intensity can each increase the rate of transpiration.

A potometer records water uptake of $0.42\,\mathrm{cm^3}$, $0.38\,\mathrm{cm^3}$ and $0.40\,\mathrm{cm^3}$ in three trials, each lasting $20\,\mathrm{min}$. Calculate the mean uptake and the mean uptake rate in $\mathrm{cm^3\,min^{-1}}$. Explain why this is only an estimate of transpiration rate.