Biology for class 11 and 12

Transport in plants
Class 11
Q1. What are porins?
Ans- They are proteins which make large pores in the membrane to allow molecules to pass through.
Q.2 What are tonoplasts?
Ans- Membranes of vacuoles in plants are known as tonoplasts.
Q.3.What is diffusion?
Ans- Random movement of molecules or ions of any substance from a region of higher concentration to the region of lower concentration until an equilibrium is reached .
Q.4 What is turgor pressure?
Ans- Pressure developed in the protoplasm of the cell due to entry of water is called turgor pressure.
Q.5 What is water potential?
Ans- The free energy of water is called osmotic potential .

Neotype - It is the specimen which is considered as type specimen when holotype and original specimen are not available or are lost. For example a taxonomist describes a plant and based on this description other plants will be named, then this plant will be considered original and specimen collected from this plant will become holotype. In case both original plant and holotype are lost ,new plant of the same species of original plant serves as neotype.