Question

Very short answers

1. What is isotonic solution ?

2. What do you mean by selectively permeable membrane ?

3. Why does a cell shrinks down ?

4. What are vacuoles ?

5. Name the organal involved in the formation of lysosomes

Answer 1

1. An isotonic solution refers to two solutions having the same osmotic pressure across a semipermeable membrane. This state allows for the free movement of water across the membrane without changing the concentration of solutes on either side.

2.Definition of Selectively Permeable Membranes. All cells are enclosed with a cell membrane. Aselectively permeable cell membrane is one that allows certain molecules or ions to pass through it by means of active or passive transport.

3. Why does a cell shrinks down in salt solution?
The salt solution being hypertonic, the water potential of the salt solution is less than that of the cytoplasm of the cell. Hence water comes out of the cell through osmosis and protoplast shrinks.

4.vacuole is an organelle in cells which functions to hold various solutions or materials. This includes solutions that have been created and are being stored or excreted, and those that have been phagocytized, or engulfed, by the cell. A vacuole is simply a chamber surrounded by a membrane, which keeps the cytosol from being exposed to the contents inside. Because vacuoles are surrounded by semi-permeable membranes, they only let certain molecules through.

5. The Golgi apparatus is involved in the formation of lysosomes.