ICSE Class 9 Biology
Question 8 of 12
Skin - "The Jack of All Trades" — Question 2
Back to all questions(a) Difference between Leukoderma/Vitiligo and Albinism :
| Leukoderma/Vitiligo | Albinism |
|---|---|
| Skin pigmentation is lost from smaller or longer patches at different region of the body. | Complete loss of pigmentation all over the body including hair, eyebrows, eyelashes and even the iris. |
| Exact cause of Leukoderma is not yet known. | Albinism is a recessive trait caused due to inheritance. |
(b) Difference between Cold blooded and Warm blooded animals :
| Cold blooded animals | Warm blooded animals |
|---|---|
| Body temperature of cold-blooded animals changes with the temperature of their surroundings. | Body temperature of warm-blooded animals remains constant and is not affected by the temperature of their surroundings. |
| Cold blooded animals undergo aestivation or hibernation. | Warm blooded animals do not undergo aestivation or hibernation. |
| Example: Reptiles | Example: Mammals |
(c) Difference between Vasodilation and Vasoconstriction :
| Vasodilation | Vasoconstriction |
|---|---|
| Dilation of blood capillaries near the skin. | Constriction of blood capillaries near the skin. |
| Caused due to increase in temperature. | Caused due to decrease in temperature. |
| Leads to loss of body heat. | Conserves body heat. |
(d) Difference between Hibernation and Aestivation :
| Hibernation | Aestivation |
|---|---|
| Hibernation is a state of reduced metabolic activity and lowered body temperature that animals enter during winter (winter sleep) or periods of food scarcity. | Aestivation is a state of dormancy that animals enter during hot and dry seasons (summer sleep), typically in response to extreme heat or drought. |
| The main purpose of hibernation is to conserve energy and survive unfavorable conditions. | The main purpose of aestivation is to avoid excessive water loss and survive in arid environments. |
| Animals that hibernate experience a significant drop in metabolic rate, heart rate, and body temperature. | Animals undergoing aestivation also reduce their metabolic rate and activity, but the reduction is not as extreme as in hibernation. |
(e) Difference between Pimples and Black heads :
| Pimples | Black heads |
|---|---|
| Pimples are caused by growth of bacteria due to sebum accumulation. | Black heads are caused due to open pores getting clogged with dead skin cells and sebum. |
| Pimples appear as red, inflamed bumps on the skin. | Black heads appear black and dark due to oxidation by the air. |