Sue is setting up an experiment to test whether fly maggots select a dark or a brightly lit environment. She sets up a chamber in which there is a gradient in light intensity from one end (dark) to the other (brightly lit). The experimental hypothesis was “There will be a large difference between the number of maggots in a dark environment and the number in a brightly illuminated one.”

What is the independent variable? Select one option from the list below.
1) Light intensity 2) The reaction rate of maggots
3) The total number of maggots
4) The distance between the darkest and most brightly lit parts of the choice chamber

1 is the correct answer plz help

The number of maggots, n, is a function of (or "depends on") light intensity, i.

n = f(i)

i is the independent variable and
n is the dependent variable.
In other words n depends on i.

that mean number is correct

am i correct or not

Which do you think after reading that carefully? Number of maggots DEPENDS ON light intensity.

Therefore light intensity is independent

and
number of maggots is dependent.

thank you

Sue is setting up an experiment to test whether fly maggots select a dark or a brightly lit environment. She sets up a chamber in which there is a gradient in light intensity from one end (dark) to the other (brightly lit). In a previous question you were asked to identify an appropriate null and experimental (or alternative) hypothesis for Sue’s proposed experiment with maggots. The selected experimental hypothesis was:

“There will be a large difference between the number of maggots in a dark environment and the number in a brightly illuminated one.”
Sue will need to set up a control experiment. Which of the following is

Sue’s control condition? Select one option from the list below.

1) The same chamber and maggots but with a different light intensity gradient.

2) The same chamber and maggots but with a coloured light gradient.

3) An identical chamber with the gradient in illumination reversed.

4) An identical chamber but with maggots of a different species.

5) An identical chamber with no light gradient.

6) A chamber with a different distance between the darkest and most brightly lit parts.

7) An experiment at a different time of day.

Hypothesis:

“There will be a large difference between the number of maggots in a dark environment and the number in a brightly illuminated one.”

I want to rule out other possible reasons for the maggots clustering in one end.

First put the light on in the left end. Hopefully the maggots cluster at one end.

Second turn the left light off and the right light on.
If the maggots then move to the other end, you have some evidence for your hypothesis.

Therefore I would pick 3)

By the way, use LED lights with minimal heat generation. The maggots might be attracted to the heat, not the light :)

3 is wrong any other answer plz

i agree.