Organisation

Water and dissolved substances are transported through a plant. Complete the sentences. Choose answers from the box. **epidermis, guard cells, palisade cells, phloem, stomata, xylem** Water moves from the roots to the leaves in the ______. Water is lost from leaves through pores called ______. Dissolved sugars are transported in the ______.

**Table 3** shows the rate of transpiration in four different plant species. Calculate how many times greater the rate of transpiration of species **A** is than the rate of transpiration of species **B**. Give your answer to 2 significant figures.

Which factor could cause species **A** to have a higher rate of transpiration than species **B**?

Which environmental change would cause an **increase** in the rate of transpiration?

Which plant species in **Table 3** is most likely to live in a dry desert?

Some plants have adaptations that help them survive. **Figure 6** shows part of a gorse plant. How will the sharp spines help the gorse plant survive?

Animals also have adaptations to help them survive. A harmless hoverfly looks very similar to a wasp, which can sting. Explain why animals avoid eating the hoverfly.

**Table 4** shows information about four jellyfish. The jellyfish are listed in order of increasing size. Calculate value **X** in **Table 4**.

Describe the relationship between the size of a jellyfish and its surface area to volume ratio. Use **Table 4**.

The jellyfish in **Table 4** take oxygen into their cells by diffusion. Name **one** other substance that enters cells by diffusion. Do **not** refer to oxygen in your answer.

Suggest **two** factors that affect the rate of diffusion of oxygen into a jellyfish.

Some organisms take in oxygen using a respiratory system. In humans, gas exchange takes place in the lungs. Name the organs where gas exchange takes place in **fish**.

**Figure 8** shows parts of the human breathing system. Explain how the human breathing system is adapted to maximise the rate of gas exchange.

In the past many drugs were extracted from plants. Aspirin is a painkiller. Which plant does aspirin originate from?

Scientists have extracted chemical A from the deadly nightshade plant. Chemical A can be used as a painkiller. Table 1 shows information about where chemical A is found. The scientists usually extract chemical A from the berries of the deadly nightshade plant. Suggest one reason why berries are used instead of leaves or roots.

A deadly nightshade plant has chlorosis (yellow leaves). The mass of chemical A found in the leaves of the plant is 60% of the mass shown in Table 1. Calculate the mass of chemical A in 200 g of the leaves with chlorosis. Give your answer in mg.

This question is about the circulatory system. Figure 1 shows the human heart. Which part of the heart receives oxygenated blood from the lungs?

Which part of the heart pumps deoxygenated blood to the lungs?

A group of cells called the pacemaker controls the resting heart rate. Where in the heart is the pacemaker found?

Figure 2 shows a cross section of an artery and of a vein. Describe two ways that the structure of an artery is different from the structure of a vein.

In coronary heart disease, the coronary arteries become narrower. A build-up of fatty material can cause a blockage in a coronary artery. Table 2 shows how a blockage in a coronary artery affects blood flow. Describe the trend shown in Table 2.

Complete Figure 3. You should: • use a suitable scale for the y-axis • plot the data from Table 2 • draw a line of best fit.

Predict the blood flow in a coronary artery with a 35% blockage. Use Figure 3.

Explain the effect of a partly blocked coronary artery on the human body.

There are different treatments for a blockage in a coronary artery. Explain how one treatment for a blockage in a coronary artery works.

Design an investigation to show the effect of different types of exercise on the heart rate of athletes.

Anabolic steroids are drugs. Anabolic steroids: • increase muscle mass in humans • are banned in most competitive sports. Some athletes take anabolic steroids to improve their performance in sport. Explain how taking anabolic steroids could improve an athlete's performance.

During one stage of malaria infection, the malarial protists enter red blood cells and cause them to burst. Explain why the bursting of red blood cells causes tiredness.