Resource 2: True/false exercise on cells

Teacher resource for planning or adapting to use with pupils

Plant and animal cells: true–false exercise

The following statements are about cells.

Read each statement and then in your group decide, for each statement, whether it is true (T) or false (F). If you are not sure put ‘?’.

Write the letter or symbol to show your decision in the middle column. Use the last column to explain your reasons.

StatementTrue, false or unsureComment – reasons for your choice
1All cells have a nucleus.
2There is a cell membrane around all cells.
3All cells have a cell wall.
4Chromosomes are found in the cytoplasm.
5The cell membrane controls what the cell will look like and how it behaves.
6The nucleus controls what passes into and out of a cell.
7A nucleus is smaller than a chloroplast.
8A chloroplast is larger than a mitochondrion.
9All cells have a central cell vacuole filled with fluid.
10The cell membrane is made of cellulose.
11The nucleus is always found in the middle of a cell.
12A nucleus is smaller than a molecule.
13Some cells in your body are one metre long.
14If you looked through a magnifying glass at a red blood cell, it would look like the dot at the end of this sentence.
15A fully grown human is made of about one hundred million, million cells.
16Fifty typical cells lying side by side would measure about 1 mm.
17Cells are black and white. There is no colour in a cell.
18If you could shrink and stand in a cell, everything would be silent and still.

Teachers’ notes: statements 1–9

StatementTrue, false or unsureNotes for teachers
All cells have a nucleus.True, with some qualifications. See notes.All plant and animal cells have a nucleus. In some cells, the nucleus may have disintegrated by the time the cell reaches maturity. Red blood cells have a nucleus when they are developing. However, when they are mature and doing their job of carrying oxygen round the body, the nucleus has broken down. The whole cell is full of the oxygen-carrying pigment called haemoglobin. Bacterial cells are usually described as having a nuclear area, rather than a true nucleus, because there is not a nuclear membrane round the nuclear area.
There is a cell membrane around all cells.True
All cells have a cell wall.FalsePlant cells are surrounded by a cell membrane and outside this is a fairly rigid cell wall. The cell wall gives the plant cell a more definite shape than an animal cell. Animal cells do not have a cell wall. They are surrounded by a cell membrane only. A cell membrane is much more flexible that a cell wall.
Chromosomes are found in the cytoplasm.FalseChromosomes are found in the nucleus.
The cell membrane controls what the cell will look like and how it behaves.FalseThe nucleus controls what the cell looks like and how it behaves.
The nucleus controls what passes into and out of a cell.FalseThe cell membrane controls what passes into and out of a cell.
A nucleus is smaller than a chloroplast.FalseA nucleus is about three times as big as a chloroplast.
A chloroplast is larger than a mitochondrion.TrueA chloroplast is three or four times larger than a mitochondrion.
All cells have a central cell vacuole filled with fluid.FalsePlant cells have a central cell vacuole filled with fluid, called cell sap. Animal cells do not. Animal cells may contain one or several small vacuoles.

Teachers’ notes: statements 10–18

10The cell membrane is made of cellulose.FalsePlant cell walls are made of cellulose. Cell membranes of both plant and animal cells are made of protein and lipid.
11The nucleus is always found in the middle of a cell.FalseThe nucleus may be found in the middle or around the edge of a cell.
12A nucleus is smaller than a molecule.FalseA nucleus is much larger than a molecule. The nucleus contains chromosomes – 46 in human cells. Each chromosome is made of a DNA molecule.
13Some cells in your body are as long as metre.TrueNerve cells are made up of a compact cell body with long thread like fibres extending out from the cell body. Some of these fibres, called axons, may be up to one metre long. Nerve messages are carried along these fibres.
14If you looked through a magnifying glass at a red blood cell, it would look like the dot at the end of this sentence.True
15A fully grown human is made of about one hundred million million cells.True
16Fifty typical cells lying side by side would measure about 1 mm.True
17Cells are black and white. There is no colour in a cell.FalseChloroplasts are found in most plant cells. Chloroplasts contain the green pigment chlorophyll. Cells in flower petals will contain coloured pigments either in special structures like chloroplasts in the cytoplasm or dissolved in the cell sap. Animal cells, e.g. in the skin and eye of human will also contain coloured pigments.
18If you could shrink and stand in a cell, everything would be silent and still.False

Everything would certainly not be still. Cytoplasm is continually moving around. Molecules would be moving in and out of cells. In a muscle cell you might find yourself squeezed and released from time to time.

The swishing of the streaming cytoplasm is likely to set up vibrations. Sound is vibration. If you could manage to shrink to fit in a cell your ears could probably manage to detect these vibrations as sounds!

Resource 1: Background information on cells

Resource 3: Working with onion cells