Question

grace is observing how water moves in and out of animal cells. which statement best describes osmosis?
a) water moves across the membrane until solute concentrations are equal.
b) enzymes move across the plasma membrane until metabolism is complete.
c) atp is required to move water across the cell membrane.
d) solutes move across the membrane without regulation.

which organelle stores water in plant cells?
a) mitochondrion
b) central vacuole
c) chloroplast
d) nucleus

Explanation:

First Question (Osmosis)

• Osmosis is the diffusion of water across a selectively permeable membrane. Water moves from an area of lower solute concentration (higher water potential) to an area of higher solute concentration (lower water potential) until the solute concentrations on both sides of the membrane are equal (or equilibrium is reached).
• Option B is incorrect because enzymes are large molecules and do not move across the membrane in the context of osmosis, and osmosis is not related to metabolism completion.
• Option C is incorrect because osmosis is a passive transport process and does not require ATP (energy).
• Option D is incorrect because osmosis involves the movement of water, not solutes, and solute movement across the membrane is regulated (e.g., by transport proteins in facilitated diffusion or active transport).

Second Question (Organelle Storing Water in Plant Cells)

• The central vacuole in plant cells is a large organelle that stores water, along with other substances like nutrients, waste products, and pigments.
• Option A (Mitochondrion) is the site of cellular respiration and produces ATP, not a water - storage organelle.
• Option C (Chloroplast) is the site of photosynthesis and contains chlorophyll, not for water storage.
• Option D (Nucleus) contains the cell's genetic material and is involved in cell regulation and reproduction, not water storage.

Answer:

A) Water moves across the membrane until solute concentrations are equal.