Why is cell membrane considered a living boundary?

A. यह substances की entry और exit control करती है / It controls entry and exit of substances

Step 1: Identify the concept: this is plasma membrane function. Step 2: Cell membrane is selectively permeable and controls movement of substances in and out. Step 3: Remember cell membrane equals gatekeeper.

Step 1: concept पहचानें: यह plasma membrane function है। Step 2: Cell membrane selectively permeable होती है और cell के अंदर बाहर पदार्थों की movement control करती है। Step 3: Cell membrane equals gatekeeper याद रखें।