Please help me I don't understand.

Explanation:

Here the molecules are moving from region of low concentration to high concentration, so as it is an uphill transport also known as Active transport. So active transport requires the ATP to be carried out.

This is the normal passive transport of hydrophobic or lipid soluble substances. So as normal passive transport requires no energy but a concentration gradient. So it doesn't require the ATP to be carried out.

This is a transport system of protozoans like Amoeba which form a pseudopodia process around the food, and then engulf the substances which then is surrounded by vacoule for digestion to take place. It also doesn't require energy.

This is an example of bulk transport mechanism where large big molecules move from higher concentration to their lower concentration through special membrane proteins and then their utilisation takes place. This is also known as Endocytosis. This also doesn't require energy to be carried out.

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.