Which one of the following is an example of osmosis? A. Water enters a plant by passing through the root cell membranes. B. Pota
ssium ions enter a red blood cell through the action of a specific ion transport protein. C. The smell of freshly baked pie spreads throughout a house. D. Food in the refrigerator starts to taste like onions because the onions in the vegetable bin have been stored unwrapped.
A. Water enters a plant by passing through the root cell membranes.
Explanation:
Osmosis is a kind of passive transport i.e. no energy input is required by the cell, that involves the movement of water across a semi-permeable membrane from a region of low solute concentration/high solvent concentration to a region of high solute concentration/low solvent concentration. The movement is usually facilitated by a difference in concentration gradient between the cell's membrane and the extracellular solution.
In this question, water from the soil enters into the root's cell via its cell membrane, which acts as the semi-permeable membrane. This movement must have occured because the solute concentration in the root's cell is higher than that of the soil, forming an osmotic gradient.
Transduction. Transudction is the process where foreign DNA is introduced into a cell by a virus or viral vector. An example would be a viral transfer from one bacteria to another.
