BLG1501 Assignment 2 2025 | 11 April 2025

BLG1501
ASSIGNMENT 2
DUE DATE: 11 APRIL 2025

, BLG1501 ASSIGNMENT 1




Question 1


1.1 Write explanatory notes on the greenhouse effect.


CO2, water vapour, sulphur dioxide and other greenhouse gases in the atmosphere
intercept and absorb radiant energy emitted by the earth and reflect it back towards the
earth. This process causes some of the solar energy to be retained. Thegreenhouse
effect is believed to have contributed to the present global warming.

(Study Unit 16.4)




1.2 Distinguish between hypertonic, hypotonic, and isotonic solutions.




Osmosis is when water moves across a membrane to balance the concentration of
solutes (like salt or sugar) inside and outside a cell.


Isotonic Solution - The concentration of solutes inside and outside the cell is the same.
Water moves in and out equally, so the cell stays the same size.


Hypotonic Solution - The solution outside the cell has fewer solutes than inside the cell.
Water moves into the cell, causing it to swell and possibly burst.


Hypertonic Solution - The solution outside the cell has more solutes than inside. Water
leaves the cell, causing it to shrink.


Effect of Osmosis on Water Balance


If a cell is placed in a hypotonic solution, it gains water and may burst (in animal cells)
or become firm (in plant cells).
In a hypertonic solution, the cell loses water and shrinks.