IGCSE Biology Organisation topical questions

Name the cell structure that matches each function.

1. (a)Contains DNA and controls the cell’s activities[1]
2. (b)Absorbs light energy for photosynthesis[1]
3. (c)Supports a plant cell and gives it a fixed shape[1]

A bacterial cell is shown with a cell wall, cell membrane, cytoplasm, ribosomes and a loop of DNA.

1. (a)Name the structure, present in plant and animal cells, that this bacterial cell does NOT have.[1]
2. (b)State the function of the ribosomes.[1]
3. (c)Name the small rings of DNA often found in bacterial cells in addition to the loop.[1]
4. (d)State the function of the cell membrane.[1]

Put these levels of organisation in order from smallest to largest, and match one example to each.

1. (a)Write the four items in order from smallest to largest.[3]
2. (b)State the level the shoot system belongs to.[1]

Match each specialised cell to its function, then to one feature that helps it.

1. (a)Write each cell with its correct function.[2]
2. (b)Write each cell with the feature from the third column that helps it.[3]

A student draws a root hair cell. The drawing is 75 mm long; the real cell is 0.03 mm long.

1. (a)State the equation linking magnification, image size and actual size.[1]
2. (b)Calculate the magnification of the drawing.[2]
3. (c)State one reason the drawing is called a diagram rather than a photograph.[1]

Compare a plant cell with an animal cell.

1. (a)List three structures found in both cell types.[3]
2. (b)List two structures found only in plant cells.[2]

A student measures three specimens and the drawings made of them. The results are in the table.

1. (a)State the formula linking magnification, image size and actual size.[1]
2. (b)Calculate the magnification of the drawing of the cheek cell.[1]
3. (c)Calculate the magnification of the drawing of the chloroplast.[1]
4. (d)Calculate the magnification of the drawing of the bacterium.[1]
5. (e)Another student records the bacterium’s magnification as ×12.5. Identify the mistake that gives this answer and write the correct value.[2]

A palisade mesophyll cell in a leaf is packed with chloroplasts. A root hair cell in the same plant has no chloroplasts but has a long extension into the soil.

1. (a)Explain why the palisade cell is packed with chloroplasts.[2]
2. (b)Explain why the root hair cell has no chloroplasts but does have a long extension.[3]

Ciliated cells line the trachea, the tube that carries air to the lungs.

1. (a)Describe the specialised feature of a ciliated cell.[1]
2. (b)Ciliated cells work with mucus-making cells. Explain how the two cell types together protect the lungs.[2]
3. (c)The beating of cilia uses energy. Name the cell structure that releases energy for this.[1]
4. (d)Name the level of organisation that a layer of ciliated cells together forms.[1]
5. (e)State why a ciliated cell is described as a specialised cell.[1]

The table shows four structures found in different cell types.

1. (a)Use the table to state one structure that identifies a cell as bacterial rather than plant or animal.[1]
2. (b)Explain why the absence of mitochondria does not stop a bacterial cell releasing energy.[2]
3. (c)Name the material a plant cell wall is made of, and explain how the plant cell wall’s function differs from the cell membrane’s.[3]

A cheek cell measures 24 mm across in a micrograph taken at ×400.

1. (a)Calculate the actual diameter of the cheek cell in mm.[2]
2. (b)Convert your answer to micrometres (µm).[1]
3. (c)A second cell at the same magnification appears 12 mm across. State whether it is larger or smaller than the first cell, in mm, showing your calculation.[1]

An electron micrograph is taken at a magnification of ×25000. A mitochondrion in the micrograph appears 50 mm long. A coccus bacterium is actually 0.002 mm long and is drawn 60 mm long.

1. (a)Calculate the actual length of the mitochondrion in mm.[2]
2. (b)Convert the answer from (a) into micrometres (µm).[1]
3. (c)Calculate the magnification of the drawing of the bacterium.[2]
4. (d)State why a magnification value has no unit.[1]
5. (e)State one reason why a micrograph should include a scale bar or stated magnification.[1]

Three single-celled organisms are examined and their features recorded in the table.

1. (a)Identify the type of cell A, cell B and cell C (plant, animal or bacterial).[3]
2. (b)State the two features in the table that identify cell C as bacterial and not plant.[1]
3. (c)Name the structure that cell A and cell C both have outside the cell membrane, and state its function.[2]

A skin wound heals as new skin cells are produced. Some of the new cells become muscle cells in tiny blood vessels in the skin.

1. (a)State where all these new cells come from.[1]
2. (b)Explain why a muscle cell contains many mitochondria.[2]
3. (c)Mature red blood cells have no nucleus. Explain how this helps their function.[2]
4. (d)Name the organ system that contains blood vessels.[1]