Biology 5090/22 — May/June 2021
Cambridge O-Level · Theory · worked solutions for every part, with the mark scheme
Topics Human Nutrition · Transport in Humans · Cell Division and Reproduction · Coordination and Control · Classification · Transport in Flowering Plants · +8 more
The diagram shows the teeth in the lower jaw of a human.
Name the type of tooth labelled X and describe one function of this type of tooth.
type of tooth ______
function ______
Food can be sweetened using honey or sugar.
The graph shows how the pH of saliva in the mouth changes with time after eating food sweetened with honey or sugar.
State the lowest pH of saliva in the mouth after eating food sweetened with honey.
______
It takes more time for saliva to return to pH 7.0 after eating food sweetened with sugar than after eating food sweetened with honey.
State how much more time it takes for the pH to return to 7.0.
______
Dental decay is likely to occur when the pH of saliva falls below 5.5.
Use information from the graph to explain whether sweetening food with honey or with sugar is more likely to lead to dental decay.
State two ways to prevent dental decay.
- ______
- ______
A person with dental decay may also have gums that bleed. This makes it more likely that bacteria found in the mouth will enter the circulatory system.
Bacteria in the circulatory system can cause the blood to clot.
Small blood clots may move through the circulatory system to the coronary arteries.
Suggest and explain possible health problems that this may cause.
The rest of this paper
8 more questions- Q2Transport in Humans9M
- Q3Classification · Transport in Flowering Plants · Plant Nutrition · Disease and Immunity · Cell Division and Reproduction13M
- Q4Human Gas Exchange · Transport in Humans · Respiration9M
- Q5Human Nutrition · Movement Into and Out of Cells6M
- Q6Cell Division and Reproduction10M
- Q7Coordination and Control · [Legacy] Support, Movement and Locomotion10M
- Q8Excretion · Human Nutrition · Coordination and Control10M
- Q9Biotechnology and Genetic Modification10M