Question 1

What is the main component of biogas and natural gas?

Accepted Answer

Methane is the main component of biogas and natural gas.

Question 2

Cold foods should be kept at a temperature of

Accepted Answer

To reduce the risk of bacterial contamination, many foods must be stored in the refrigerator and thus kept below 5 degrees Celsius. These foods are often classified as ‘high-risk foods’ and include – meat, poultry, dairy, seafood, eggs, smallgoods and cooked rice and pasta. This also refers to ready-to-eat foods that have high-risk foods as ingredients and include – casseroles, quiche, pasta salad, pizza, sandwiches and many cakes. By keeping these high-risk foods under 5 degrees Celsius it stops them from entering the ‘danger-zone’ – temperatures between 5 degrees Celsius and 60 degrees Celsius. The danger-zone is the temperature zone which provides bacteria with the perfect environment to rapidly grow and multiply to numbers that cause food poisoning.

Question 3

Plant cell walls consist mainly of

Accepted Answer

Plant cell walls are mostly made up of the molecule cellulose. Cellulose is a polysaccharide, a complex sugar made of long chains of glucose. The cell wall must be made of thick and strong material as it provides the structural shape of the plant and protection from insects and microorganisms.

Question 4

Which of these is an example of negative feedback?

Accepted Answer

Eating raises blood sugar levels, insulin stimulates the lowering of blood sugar level. In this example the response to the stimulus (increased blood sugar levels) opposes that stimulus (by lowering blood sugar levels).

Question 5

Which of the following statements describes the glycemic index of foods?

Accepted Answer

The glycemic index or glycaemic index is a number associated with the carbohydrates in a particular type of food that indicates the effect of these carbohydrates on a person's blood glucose (also called blood sugar) level. A value of 100 represents the standard, an equivalent amount of pure glucose. The GI represents the rise in a person's blood sugar level two hours after consumption of the food.

Question 6

What is the science of mapmaking called?

Accepted Answer

The art and science of map making is called Cartography.

General Science Questions