Classification

Yeast is a fungus used in the production of beer.

Name the part of a yeast cell that is made of chitin.

Name the carbohydrate stored in the cytoplasm of a yeast cell.

In beer production, yeast releases carbon dioxide as a waste product. A student uses this apparatus to investigate the effect of temperature on carbon dioxide production in yeast.

The student counts the number of carbon dioxide bubbles released per minute at different temperatures. The table shows the student’s results.

Describe how the student could change the temperature of the water during the investigation.

Describe how the student makes sure that the yeast cells respire anaerobically.

Give the independent variable in this investigation.

Give three ways in which the student could improve this investigation.

The diagram shows the alimentary canal of a rabbit with some parts labelled.

The table lists descriptions of some parts of the alimentary canal. Complete the table by giving the correct part from the diagram to match each description. One has been done for you.

Explain how the liver helps digestion in the alimentary canal.

Rabbits eat grass. The diagram shows the cell wall of a leaf cell from a grass plant. Complete the diagram by drawing and labelling other structures in this leaf cell.

Grass cell walls are made of cellulose. Rabbits cannot digest cellulose. Bacteria living in the large intestine of rabbits can digest cellulose into glucose. Rabbits eat their own faeces to obtain this glucose.

Give two differences between the structure of bacterial cells and the structure of plant cells.

Describe a test to show that rabbit faeces contain glucose.

A scientist does an experiment using a photosynthetic organism and bacteria. The photosynthetic organism lives in water and has a spiral chloroplast. The bacteria need oxygen to survive. The scientist shines different colours of light on the photosynthetic organism and adds the bacteria to the water. The diagram shows the location of the bacteria during the experiment.

Use the information from the diagram to suggest two conclusions that can be made about photosynthesis.

The scientist concludes that bacteria are living organisms. Explain how the diagram supports this conclusion.

Name two structures found in bacteria.

Yeast is an organism used in the production of beer. The diagram shows a yeast cell.

Give the letter of the part made of chitin.

Give the letter of the part that contains glycogen.

Yeast releases carbon dioxide when beer is made. A student uses this apparatus to measure the rate of carbon dioxide production by yeast.

The solution contains yeast cells. Name two substances in the solution.

Every three minutes, the student records the position of the drop of ink using the scale. The table shows the student’s results.

Calculate the difference between the rate of carbon dioxide production in the first three minutes and the rate in the final three minutes. Show your working.

difference in rate =_........ mm per minute

The student then investigates the effect of temperature on the rate of carbon dioxide production by yeast. He measures the volume of carbon dioxide produced rather than the distance moved by the drop of ink. The graph shows his results.

Give the optimum temperature for the production of carbon dioxide.

Explain why the rate of carbon dioxide production is slow at low temperatures.

Suggest how the student could modify the apparatus to vary the temperature.

The passage describes how different organisms are classified into groups. Complete the passage by writing a suitable word or words in each of the spaces.

Plants are multicellular organisms. They have chloroplasts to carry out photosynthesis and cell walls made of_........ . They store carbohydrate as_........ or as sucrose.

Animals are also multicellular but do not carry out photosynthesis. They are able to move from place to place and are always described as_........ in food chains. They store carbohydrate as_........ .

Bacteria are single-celled organisms. They do not have a nucleus. Instead, they contain a circular_........ and smaller circles of DNA called_........ . Most bacteria feed off other living or dead organisms but some bacteria can make their own food by_........ .

Examples of bacteria include Lactobacillus, used in the production of_........

from milk, and Pneumococcus, that acts as a_........ causing the disease_........ .

The photograph shows the logs left behind after an area of forest has been cut down.

These logs are decomposed by fungi.

Describe how fungi decompose tree logs.

Some of the logs removed from the forest are used to make garden benches. The photograph shows a garden bench.

The garden bench is painted with a fungicide solution. This prevents the wood being decomposed because fungicide kills fungi. There are different fungicides that can be used. Design an investigation to find out which fungicide is best at preventing the decomposition of wooden logs. Your answer should include experimental details and be written in full sentences.

The fungus Fusarium venenatum is grown in a fermenter to make a food product called mycoprotein.

Name the molecule that a fungus uses to store carbohydrate.

Name the thread-like structures that make up the mycelium of a fungus.

Mycoprotein contains low levels of fats and is high in protein. Suggest the benefits of each of these to a human diet.

Food production can be increased by using genetically modified plants that are resistant to disease. Explain how enzymes can be used to genetically modify plants.

Yeast is a single-celled fungus. The diagram shows a yeast cell with parts labelled A to F.

The table lists functions of different parts of the yeast cell. Complete the table by giving the letter of the part that carries out the function.

The table lists statements. Put a tick () in the boxes next to the statements that are correct for yeast.

A student is given two samples of carbohydrates. He tests to see if one is glucose and the other one is starch. Describe the two chemical tests he should use to identify each carbohydrate.

Different groups of organism store carbohydrate as different molecules. Complete the table to show an example from each group of organisms and the molecule they use to store carbohydrate.

The table gives features of three different groups of organism. Complete the table by putting a tick () in the box if the organisms in the group have the feature and a cross () in the box if the organisms in the group do not have the feature. The first one has been done for you.

The table shows four different groups of organisms. Complete the table to give an example for each group.

Different groups have different features. Complete the table below to show if the feature is present in all, some or none of each group. Some of the table has been completed for you.

Give one way in which the structure of a virus differs from a bacterium.

Bacteria and viruses can act as pathogens. Give an example of a disease caused by a virus.

The photograph shows an organism called lichen growing on the surface of a tree.

Lichens are unusual because they consist of a fungus and an algae living together.

The fungus grows hyphae that help it feed by saprotrophic nutrition. Explain what is meant by the term saprotrophic nutrition.

The diagram shows a fungal hypha with parts labelled A to D.

Which letter labels the part made from chitin?

Which letter labels the part made from glycogen?

Algae are green organisms that carry out photosynthesis.

Name the molecule that makes algae look green.

Write the word equation for photosynthesis.