Biology
Human biology and ecology — Topics 7-14 and 19-21
- 1.
Explain two ways in which a red blood cell is adapted to transport oxygen efficiently.
[4 marks] · no calculator - 2.
Grass stores 18 000 kJ of energy. Rabbits feeding on the grass store 1800 kJ. Calculate the percentage energy transfer and explain why not all energy is transferred.
[4 marks] - 3.
Describe the path taken by blood as it flows through the heart from the vena cava to the aorta, naming the chambers and valves in order.
[4 marks] · no calculator - 4.
Explain why the left ventricle of the heart has a much thicker muscular wall than the right ventricle.
[3 marks] · no calculator - 5.
Outline the roles of insulin and the liver in maintaining a stable blood glucose concentration after a meal.
[3 marks] · no calculator - 6.
Describe the process of gas exchange occurring in the alveoli of the lungs.
[4 marks] · no calculator - 7.
A predator-prey population graph shows fox and rabbit numbers oscillating, with fox numbers peaking shortly after rabbit numbers peak. Explain this pattern.
[4 marks] · no calculator - 8.
Outline the function of the kidney in removing urea from the blood, and state why urea must be removed from the body.
[3 marks] · no calculator - 9.
Explain how deforestation of a tropical rainforest can lead to a reduction in local biodiversity.
[3 marks] · no calculator - 10.
Construct a simple food chain from the following organisms: fox, grass, rabbit. State which organism is the producer.
[3 marks] · no calculator - 11.
Describe how the volume of the thorax (chest cavity) changes during inhalation, and explain how this causes air to enter the lungs.
[4 marks] · no calculator - 12.
State three features of the alveoli that adapt them for efficient gas exchange.
[3 marks] · no calculator - 13.
Describe three features of the villi lining the small intestine that adapt them for the efficient absorption of digested food.
[3 marks] · no calculator - 14.
Compare the structure of arteries and veins, explaining how each structural difference relates to its function.
[4 marks] · no calculator - 15.
Explain one advantage of a double circulatory system, in which blood passes through the heart twice on each complete circuit, compared with a single circulatory system.
[2 marks] · no calculator - 16.
Distinguish between excretion and egestion.
[2 marks] · no calculator - 17.
Describe two physiological responses of the human body to a rise in body temperature above normal, and explain how each response helps to cool the body.
[4 marks] · no calculator - 18.
Describe the pathway of a simple reflex arc, such as withdrawing a hand from a hot object, naming the structures involved in order.
[5 marks] · no calculator - 19.
State two differences between nervous control and hormonal (chemical) control of the body.
[2 marks] · no calculator - 20.
During a stressful or dangerous situation, adrenaline is released into the blood from the adrenal glands. State two effects of adrenaline on the body, and explain how each effect prepares the body for a 'fight or flight' response.
[4 marks] · no calculator - 21.
Describe how carbon dioxide is removed from, and returned to, the atmosphere as part of the carbon cycle.
[3 marks] · no calculator - 22.
A pyramid of biomass for a food chain becomes narrower at each successive trophic level. Explain why biomass decreases at each higher trophic level.
[3 marks] · no calculator - 23.
Describe the shape of a typical sigmoid (S-shaped) population growth curve, naming its three main phases.
[3 marks] · no calculator - 24.
Excess fertiliser washes from farmland into a nearby river. Describe how this can lead to the death of fish in the river.
[4 marks] · no calculator - 25.
State four components of a balanced human diet, other than water, and state one function of each.
[4 marks] · no calculator