Question

1. The current size of the human population on Earth is

A. approximately 7.5 billion and decreasing.

B. approximately 7.5  billion and increasing.

C. approximately 7.5 billion and remaining stable.    

D. approximately 7.5 billion but there is no way to tell where the population is heading.

E. none of the above.

2. For findings of scientific research to be accepted the findings must be

A. repeatable/reproducible

B. involve a large enough sample size to be significant

C. made following the recognized scientific method

D. conducted in an objective fashion

E. all of the above

3. Risk assessment attempts to measure the probability of an event happening as well as assessing the severity of the event should it happen

A. True            B. False

4. Regarding energy, the Earth is a closed system

A. True            B. False

Answer 1

Answer for Question number 1: Option B-approximately 7.5  billion and increasing.

Explanation: The current population on Earth is approximately 7.5 billion and it is increasing as the birth rate on the Earth is higher than the death rate so the overall growth rate is positive. Hence Option B is the right answer.

As explained above the growth rate on Earth is higher than the death rate, hence the population size cannot decrease, So, option A cannot be the right answer.

The population on the Earth is significantly increasing due to the imbalance of birth rate and growth rate. So, the options C, D, and E cannot be the right answer.

Answer for Question number 2: Option E-  all of the above.

Explanation: A scientific research should always be an objective oriented otherwise the work would fall in every direction, It should be reproducible, i.e. one can get the same result following the same experimental conditions anywhere, the scientific experiment should also be done on a large sample size so that the results are more significant, one should perform the work following the recognized scientific method to be applicable and reproducible.
So, in the question all the given statements are true, that's why Option E is the right answer.

Answer for Question number 3: Option A- True

Explanation: The risk assessment is the process of evaluating the identification of the risk or event, evaluating the probability and the severity of the event(i.e. risk analysis). SO, the statement in the question is true. Hence Option A is the right answer while Option B is not.

Answer for Question number 4: Option B- False

Explanation: Regarding energy, the Earth is an open system. Because one of the principal sources of energy on earth is the sun which comes in the form of radiation and the released energy from the Earth goes back in the space in the form of radiation. This exchange of energy makes Earth an open system for energy. So Option B is the right answer and Option A is not the right answer.