Active transport requires energy because unlike osmosis and diffusion which are passive transport methods which sees where the particles are moving along the concentration gradient, in active transport, the particles are moving against the concentration gradient and as such energy through ATP is needed for the particles to be transported.
That question, this incomplete. The full question is:
3. Three redwood trees are kept at different humidity levels inside a greenhouse for 12 weeks. One tree is left outside in normal conditions. The heights of the trees are measured once a week. What are the dependent variables, independent and the controlled variable of this experiment?
Answer:
- Independent variable: different humidity levels
- Dependent variable: the heights of the trees
- controlled variable: the types of trees
Explanation:
An independent variable is one that exerts an influence within the experiment and can be measured, acting on other elements to promote the observation of a result. As the experiment seeks to observe the influence of humidity on the height of the tree, we can say that humidity is the independent variable.
Dependent variable is that which is influenced by the independent variable to generate a result that can be observed, can also be measured. As the experiment wishes to analyze how the height of the trees was affected by the level of humidity, we can say that the height of the trees is the dependent variable.
Controlled variable is that which is present in the experiment in a constant and equal way, cannot be measured. This variable is the type of trees.
Answer:9:3:3:1
Explanation: Just took the test!
In some places, especially some new wells that have just been drilled,
the oil is under pressure, and it brings itself to the surface as soon as
you drill a 'pipe' for it to rise through.
In most oil wells, there's a pump bobbing up and down day and night,
pumping the oil up out of the well.
When the well is so old that even a pump isn't very effective, water is
often forced down the well under pressure, and the water forces the
oil back up through the pipe.
