Stomach ulcers are sores that develop in the lining of the stomach.
The mucus produced by the stomach prevents bacteria from reaching the lining of the stomach.
Stomach ulcers can be caused by infection with the bacterium Helicobacter pylori.
These bacteria reproduce in the stomach as it provides all the conditions required for the growth of bacteria.
Explain the conditions needed for the growth of bacteria.
The plant Cibotium barometz is native to several countries in East Asia.
The photograph shows hairs on the surface of this plant.
Mokkie, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
Extracts from the hairs on this plant have antimicrobial properties.
An investigation compared the use of this extract and the drug omeprazole to treat stomach ulcers in rats.
The mass of mucus and the area of ulcer were measured in five groups of rats.
The table shows the treatments and the results of this investigation.
Group | Treatment / mg kg-1 |
Mean mass of mucus / g |
Mean area of ulcer / mm2 |
Control rats with no ulcer | 0.00 | 2.28 | 0.00 |
Control rats with ulcer | 0.00 | 0.75 | 802.71 |
Rats with ulcer treated with omeprazole | 20.00 | 1.92 | 95.71 |
Rats with ulcer treated with extract | 125.00 | 1.87 | 202.80 |
Rats with ulcer treated with extract | 500.00 | 2.17 | 172.80 |
(Source: adapted from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5244617/)
Calculate the percentage decrease in the mean areas of ulcer of the rats treated with omeprazole compared with the control rats with ulcer.
(2)
Explain the results of this investigation.
Use all the information in Question 6 to support your answer.
(6)
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