Respiration

Which statement is correct about anaerobic respiration in plants?

A It produces glucose.

B It produces carbon dioxide.

C It produces lactic acid.

D It produces oxygen.

The diagram shows the carbon cycle.

Complete the two labels in the diagram to identify the processes involved in the carbon cycle.

Explain the role of decomposers in the carbon cycle.

Decomposition can take place aerobically or anaerobically.

What is meant by the term anaerobically ?

Human activity has led to rising carbon dioxide levels in the atmosphere.

This contributes to global warming and reduces global biodiversity.

Describe two ways in which human activity can reduce local biodiversity.

A scientist investigates the effect of temperature on anaerobic respiration in yeast.

The diagram shows the apparatus they use.

This is the method they follow:

• Collect the gas produced by the yeast for five minutes.

• Increase the temperature of the water bath.

• Repeat the investigation with fresh sugar solution.

• Do each temperature three times.

Suggest why the scientist used fresh sugar solution each time.

Identify one variable the scientist should keep constant throughout the experiment.

Tick (✓) one box.

Which gas is collected by the scientist in the gas syringe?

When calculating the mean for 55 °C, they did not include Trial 1.

Give the reason why.

Plot the mean values from the table on the graph.

Draw a curve of best fit.

Anaerobic respiration is an enzyme-controlled reaction.

Explain the results between 15 °C and 35 °C. Include ideas about enzyme particles.

The scientist concludes that the best temperature for anaerobic respiration is approximately 40 °C.

How could they alter their investigation to identify a more accurate temperature?

A scientist investigates the effect of temperature on anaerobic respiration in yeast.

The diagram shows the apparatus they use.

This is the method they follow:

• Collect the gas produced by the yeast for five minutes.

• Increase the temperature of the water bath.

• Repeat the investigation with fresh sugar solution.

• Do each temperature three times.

Suggest why the scientist used fresh sugar solution each time.

Identify one variable the scientist should keep constant throughout the experiment.

Tick (✓) one box.

Which gas is collected by the scientist in the gas syringe?

When calculating the mean for 55 °C, they did not include Trial 1.

Give the reason why.

Plot the mean values from the table on the graph.

Draw a curve of best fit.

Anaerobic respiration is an enzyme-controlled reaction.

Explain the results between 15 °C and 35 °C. Include ideas about enzyme particles.

The scientist concludes that the best temperature for anaerobic respiration is approximately 40 °C.

How could they alter their investigation to identify a more accurate temperature?

15* (a) Sickle cell disease is a blood disorder causing some red blood cells to become sickle shaped.

The diagram shows red blood cells from a person with sickle cell disease.

The change in shape causes the cells to clump together. This makes sickle shaped red blood cells less efficient at carrying out their role.

Symptoms of sickle cell disease are tiredness and a lack of energy.

Explain why someone with sickle cell disease has these symptoms. Include information from the diagram.

The photograph shows part of an artery seen using a light microscope.

The image has been magnified 8 times.

Calculate the actual thickness of the artery between points X and Y in m.

Give your answer in standard form.

Actual size =........ m

Explain how the structure of a vein is adapted to its function.

Respiration releases energy from food. The energy content of food can be measured by burning the food. A student measures the energy content of some different foods.

The student finds the energy content by measuring the change in temperature of the water.

Identify the piece of apparatus labelled X in the diagram.

The table shows the change in temperature for one type of food.

Calculate the energy content of the food using this formula.

Energy content = 20 × 4.2 × change in temperature

The student converted all their results to find the energy content in kJ per gram of food.

The graph shows the results.

What is the energy content of food type D ?........ kJ per gram

Eating food type B provides the body with more ATP molecules than eating the same mass of food type E.

Use your knowledge of cellular respiration to explain why.

The diagram shows some of the levels of organisation within the ecosystem.

Complete the diagram using words in the list.

Explain why the carbon cycle is important to plants.

What are the product(s) of anaerobic respiration in animals?

A Alcohol

B Alcohol and carbon dioxide

C Lactic acid

D Lactic acid and carbon dioxide

Fig. 16.1 shows a single-celled organism called an alga.

The alga cell is a eukaryotic cell.

Describe two differences in structure between eukaryotic and prokaryotic cells.

Explain why chloroplasts are needed for photosynthesis.

Fig. 16.2 shows algae growing on the surface of a lake.

In the summer the area covered by the algae increases.

Other plants growing at the bottom of the lake receive less light.

Explain how this could affect the growth of the plants at the bottom of the lake.

Compare the process of photosynthesis with the process of aerobic respiration.

Which gas makes the bubbles?

* The students think they could improve their method.

They will count the bubbles three times at each temperature. This would show up any anomalous results.

Describe other ways they could improve their method to obtain more precise and repeatable results.

For each improvement explain why it is needed.

The students count the bubbles three times at each temperature. They then calculate the mean number of bubbles at each temperature.

The table shows their results.

Plot the results on the grid.

Draw a line of best fit.

Respiration is an enzyme controlled reaction.

Use ideas about enzymes to explain the pattern in the results.

Look at the diagram of the water cycle.

Complete these sentences about the diagram.

Choose words from the list.

combustion evaporation photosynthesis precipitation

run-off respiration transpiration

Arrows labelled A represent the process of........

Arrows labelled B represent the process of........

Arrows labelled C represent the process of........

How many predators does the shrimp have in this food web?

When plant material is decomposed by fungi, there is an increase in temperature.

Complete the sentences to explain why.

Choose words from the list.

endothermic excretion exothermic

respiration photosynthesis

During decomposition fungi release energy from the plants by the process of

........

This process releases energy as heat because the reaction is

........

Dogfish and minnows are fish that live in lakes.

Dogfish build nests to lay their eggs in. Minnows lay their eggs in the same nests as dogfish.

The dogfish protect the nest from predators.

Minnows move in and out of the nest. This helps to remove harmful bacteria and get oxygen to the eggs.

Dogfish usually eat minnows. When the dogfish have eggs they do not eat minnows.

Dogfish have two different interactions with the minnows.

Write down the names of these two types of interactions.

Describe when each interaction takes place.

One of the interactions benefits both minnows and dogfish.

Explain how.

Compare the structures of these two carbohydrates.

Two students investigate anaerobic respiration using yeast with sucrose solution.

They measure the volume of gas collected every 5 minutes for 40 minutes.

The students then repeat the investigation using yeast with glucose solution.

Explain how and why the temperature of the solution could change during the investigation and how this could be controlled.

Cardiovascular disease (CVD) is a major cause of death in the UK.

Look at the diagram of the external features of a heart.

The coronary artery supplies the cardiac muscle with oxygen.

Label the diagram to show the position of one of the coronary arteries.

Angina is a symptom of CVD. Pain from angina is caused by cardiac muscle respiring anaerobically.

Explain why angina causes pain.

A 55 year old patient has severe chest pains due to a narrowed coronary artery.

The diagram shows the cross-section of a normal coronary artery and the patient’s artery.

Normal coronary artery
Patient’s coronary artery

The cross-sectional area of the normal coronary artery lumen is 18.1 mm².

Calculate the cross-sectional area of the lumen of the patient’s artery.

Use the equations:

Give your answer to 2 significant figures.

Calculate the percentage reduction in cross-sectional area for the lumen of the patient’s artery.

CVD can be treated by different combinations of lifestyle changes, medicine and surgery.

Look at the information on CVD and how much the coronary artery has been narrowed

Justify why the patient would need surgery.

* Doctors rely on different types of surgery to treat cardiovascular disease.

The table shows features of three surgical treatments.

Evaluate the three surgical treatments and decide which would be the best type of surgery for the 55 year old patient.