Question

which statement best describes active transport in cells? it moves substances from high to low concentration without using energy it moves substances across the membrane using only channel proteins. it allows only water molecules to pass through the plasma membrane. it moves substances from low to high concentration using energy from atp. a student sprays perfume in one corner of the classroom. after a few minutes, students on the other side of the room begin to smell it. which process best explains how the scent spread throughout the room? 1 point endocytosis osmosis active transport diffusion when first focusing on a specimen under the compound microscope, which * 1 point objective should you use first?

Explanation:

1. Active transport in cells moves substances against the concentration gradient (from low to high concentration) and requires energy in the form of ATP. The first option describes passive - transport (diffusion), the second option is a form of facilitated diffusion, and the third option describes osmosis.
2. Diffusion is the movement of molecules from an area of high concentration to an area of low concentration. Endocytosis is the process of taking substances into the cell, osmosis is the diffusion of water, and active transport requires energy and is not related to the spread of perfume in a room.
3. When first focusing on a specimen under a compound microscope, the low - power objective should be used first. It provides a wider field of view and makes it easier to locate the specimen.

Answer:

1. It moves substances from low to high concentration using energy from ATP.
2. Diffusion
3. Low - power objective