CIE Biology Paper-5: Specimen Questions 42 - 44 of 62
Question number: 42
Write in Brief
Question number: 43
Describe in Detail
Fermentation is a metabolic process that converts sugar to acids, gases or alcohol.
Prepare a glucose yeast mixture and test the fermentation product, ethanol
Requirement (per set)
- glucose powder (low hazard) approx. 5g
- yeast powder (fast acting) approx. 1g
- small conical flask
- cotton wool bung
- measuring cylinder
- boiling tube
- accurate balance (per group)
- Add the 5 gm. of glucose to 50 ml of warm water in a conical flask.
- Add yeast and place the cotton wool bung on the neck of the flask.
- Leave in warm place or in a water bath at round 30°C and see temperature.
- Once the mixture has fermented, test the gas produced in the conical flask using limewater by driving the gas from the flask into the boiling tube and shaking.
- Limewater turns cloudy if there is enough carbon dioxide present.
- Yeast contains an enzyme (zymase) and this catalyses the fermentation process, the formula of which is below:
Question number: 44
Write in Short
There are four types of blood cells are given below (magnified 1000 times). Identify all four blood samples are related to which organisms.
Sample A-Frog blood cells
Sample B-Turtle red blood cells
Sample C-Chicken blood cells
Sample D-Human blood cells