Practise Eukaryotes and prokaryotes. 11 exam-style questions plus unlimited generated ones on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Cover the answers and test yourself. The app has these as flashcards that come back just before you'd forget them.
Cells can be classified as eukaryotic or prokaryotic. Name the small rings of DNA found in some bacterial cells.
plasmids
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Cells can be classified as eukaryotic or prokaryotic.
(a) Which cell is a prokaryotic cell? Tick (✓) one box.[1]
Bacterial cell
Cheek cell
Palisade cell
Sperm cell
(b) Name the small rings of DNA found in some bacterial cells.[1]
(c) Give two ways in which the genetic material in a bacterial cell is different from the genetic material in an animal cell.[2]
(d) Bacterial cells and plant cells both have a cell wall. Give one other structure that is found in both bacterial cells and plant cells.[1]
Show the answer and mark scheme
(a)Answer: Bacterial cell
(b)Answer: plasmids
plasmid(s)
(c)
(bacterial) genetic material / DNA is not enclosed in a nucleus
(bacterial) DNA is a single loop / is circular
bacteria may also have plasmids / small rings of DNA
(d)
cell membrane / cytoplasm
Question 2Medium6 marks
{table} shows the lengths of three cells.
[object Object]
(a) Convert the length of the human egg cell into micrometres (µm). 1 mm = 1000 µm[1]
(b) How many times longer is the human egg cell than the bacterium?[1]
(c) By how many orders of magnitude is the egg cell larger than the bacterium?[1]
(d) Give the length of the bacterium in metres. Give your answer in standard form.[1]
(e) Give two structures found in the bacterium that are not found in the human egg cell.[2]
Show the answer and mark scheme
(a)Answer: 120 µm
120 (µm)
(b)Answer: 100 times
100
(c)Answer: 2 (a factor of 102)
2 / 102
(d)Answer: 1.2 × 10−6 m
1.2 × 10−6 (m)
(e)
cell wall
plasmid(s)
a single (circular) loop of DNA (not enclosed in a nucleus)
Question 3Hard8 marks
Cyanobacteria are single-celled prokaryotes that live in ponds. They carry out photosynthesis. One cyanobacterium cell has a diameter of 5 µm.
(a) A student said: 'Cyanobacteria photosynthesise, so they must be plant cells.' Give two reasons why the student is wrong.[2]
(b) Cyanobacteria do not have chloroplasts. Suggest how cyanobacteria are still able to carry out photosynthesis.[1]
(c) A palisade cell from a pond plant is 0.1 mm long. Calculate how many times longer the palisade cell is than the diameter of the cyanobacterium.[2]
(d) Give the diameter of the cyanobacterium in metres. Give your answer in standard form.[1]
(e) Scientists think that the first chloroplasts formed when a small photosynthetic prokaryote was taken inside a larger cell and continued to live there. Chloroplasts contain their own small loops of DNA. Suggest how this observation supports the scientists' idea.[2]
Show the answer and mark scheme
(a)
cyanobacteria have no nucleus / their genetic material is not enclosed in a nucleus
cyanobacteria have a single loop of DNA / may have plasmids
cyanobacteria have no chloroplasts
cyanobacteria are much smaller than plant cells
(b)
they contain chlorophyll (in the cytoplasm / on membranes) to absorb light
(c)Answer: 20 times
0.1 mm = 100 µm
(100 ÷ 5 =) 20
(d)Answer: 5 × 10−6 m
5 × 10−6 (m)
(e)
prokaryotes have their DNA in loops / as a single loop / as plasmids
so chloroplast DNA is like prokaryotic DNA (and is separate from the nucleus), suggesting chloroplasts were once prokaryotic cells