Question
Question: The pectic substances and cellulose of wall of root hairs are- A) Hydrophilic B) Chemophillic ...
The pectic substances and cellulose of wall of root hairs are-
A) Hydrophilic
B) Chemophillic
C) photophilic
D) Thermophilic
Solution
As we know that, Root hairs are present at the tip of the root region. They help in uptake of water and nutrients that are present in the soil and provide it to plant upper parts. Pectic and cellulose are plant cell wall substances.
Complete answer:
Option A Hydrophilic- As we discussed that-pectin is found in cell walls of root cells that form the network matrices of cell walls and they are hydrophilic. These networks are formed by cross-linking. Cellulose forms microfibrils in the wall and they are made of joining glucose monomers. This hydrophilic nature helps both the substances to absorb water into root hairs.
So, option A is correct
option B Chemophillic – this option is inappropriate as the term Chemophillic in biology is used in human beings. Substances which are chemically fused or traces of harmful chemicals are known to be Chemophillic substances. In plants there is no such interaction.
So, option b is incorrect.
Option C Photophilic- photophilic terms as plants which grow in open places and require huge amounts of sunlight as photo means- light. They cannot withstand long periods of staying in a shadow or dark room. Plants like-sorghum, maize, corn, sugarcane. They have thick parenchyma and a large number of stomata. There are chloroplasts in cells. They show a high rate of photosynthesis.
So, option C is incorrect.
Option D Thermophilic- As we can guess by the name- thermo means temperature, so plants which can withstand more temperature or hot-region grown plants are said to be thermophilic. Thermophilic plants can tolerate temperature up to degrees. Some desert plants, fungi, algae and eubacteria can tolerate about degrees. Thermophilic plants can survive in hot conditions as their leaves store water in them. They ooze out less water in transpiration and their absorption rate is high.
So, option D is incorrect.
So the correct answer is option A.
Note:
Root system in plants has a monocot and dicot system. Monocot roots are fibrous and have a wide network. Dicot has reduced pith and they have tap roots.