12th Biology Practical ~ (Part B) 3. study of inhibition and using dried seeds and raisins

12th Biology practical book answers pdf Maharashtra board 

~Study of inhibition and using dried seeds and raisins

Observation:

The seeds or raisins kept or soaked in water show change in their volume showing swollen structure and seed coat/ raisins shows softening.

 

Conclusion:

1) Seed coat contain hydrophilic substances which imbibe water and therefore seed's swell up & their volume increases. Thus, they demonstrate the phenomenon of imbibition. 2) the swelling of raisins also demonstrates the phenomenon of imbibition.

 

Questions

Q. 1. What is imbibition?

Imbibition is absorption of water (or any solvent) without forming solution.

Q. 2. Distinguish between diffusion and imbibition.

Imbibition is absorption of water by (colloids) general surface without farming solution.

Diffusion means movement of solid, liquid or gaseous molecules from regions of high conc. to region of low conc.

Q. 3. What will be the result if fresh grapes fruit are dipped for some time in strong salt solution?

If grapes are placed or dipped for sometimes in strong salt solution having more conc. than cell sap, exosmosis will happen & grapes will shrink.

Q. 4. Define and or explain: a. exosmosis b. endosmosis

Exosmosis is movement of water out of the cell. It occurs when cells are placed in hypertonic solution. Cells shrinks as a result of exosmosis.

Endosmosis is movement of water into the cell. It occurs when cells are placed in hypotonic solutions. Cells may swell as a result of endosmosis.

Q. 5. Give any two examples of imbibition in day-to-day life.

1) Absorption of water by seeds

2) Absorption of water by dry wood

 

Fin :)