Why is Air Bubbled and Beaker Covered in Plant Root Experiment?

[Barclay]

Homework Statement

A high school experiment shows a plant immersed in a solution of nitrate ions. The beaker is closed but has an air vent passing into the solution.
Q. Why is air bubbled into the solution
Q. Why is the beaker covered with black paper

Homework Equations

The Attempt at a Solution

My answer Q2. The air will provide oxygen to the root cells for them to respire.
My answer Q2. To mimmic real plant conditions/ environment in soil. The roots are away from light in soil too.

Q2. Is my main problem. I'm just guessing the answer.

Please comment on my answers
Thank you

 

[Borek]

Unless the question refers to a known experiment that was discussed earlier IMHO it is worded in a way that makes it impossible to give any reasonable answer. It is just way too ambiguous.

 

[Barclay]

Question ... it is worded in a way that makes it impossible to give any reasonable answer ... too ambiguous.

Okay I'll try again. The question says "A student uses apparatus (shown as diagram but I'll describe the set up below) to show if nitrate ions help plants to grow".

Diagram shows two beakers containing minerals in solution. Only one of the brakers contains the nitrate.
The roots of a 2 plants are inserted into the different solution and then the plants are inspected for growth weeks later.
The beakers are closed at the top but have an air vent passing into the solution through which air can be bubbled into the solution.
Q1. Why is air bubbled into the solution
Q2. Why is the beaker covered with black paper

A2. The air will provide oxygen to the root cells for them to respire.
A2. To mimmic real plant conditions/ environment in soil. The roots are away from light in soil too.

Q2. Is my main problem. I'm just guessing the answer.

 

[Borek]

Can't think of a better answer.

 

[Barclay]

Can't think of a better answer.

Thanks. Q2 answer sounds too simplistic so was having doubts