Answer:
The correct answer will be
Case I
1. Constant variable- amount of water, amount of food, temperature and exercise wheel
2. Independent variable- amount of sunlight
3. Dependent variable- length of sleep
4. Data to be collected- length of sleep
Case II
1. Constant variable- amount of water, temperature, amount of sunlight and exercise wheel
2. Independent variable- amount of food
3. Dependent variable- weight of mice
4. Data to be collected-weight of mice
Explanation:
A scientific experiment is designed in a way that it must include three types of variable in the experiment:
1. Independent variable- The variable which can be changed or modified and influence another variable
2. Dependent variable- the variable which has to be studied in the experiment
3. Constant variable- the variable which is kept the same throughout the whole experiment.
In case I since the research was done to study how the amount of light affect the length of the sleep, therefore, the length of the sleep is being studied by changing the amount of sunlight and others kept constant.
Similarly, the case II study was done to study how the amount of food affect the weight of the mice, therefore, the amount of food must be changed to study the weight of mice and data must be collected for the weight of the mice.
