Question

Match the reasons given in column 2 to the features of cacti in column 1.

$\begin{array}{cc}Featureofcacti& Reasons\\ a.\text{Spiny leaves}& \left(i\right)\text{Absorbing water from depths of soil}\\ b.\text{Thick, round fleshy stems}& \left(ii\right)\text{Prevent loss of water by transpiration}\\ c.\text{Deep roots}& \left(iii\right)\text{Store water}\\ d.\text{Closed stomata during the day}& \left(iv\right)\text{Prevent animals from eating the cactus}\\ e.\text{Carbon dioxide storage during the night}& \end{array}$

• A. a – (iv) ; b – (ii) ; c - (iv), (iii) ; d – (i) ; e – (iii), (ii)
• B. a – (ii), (iv) ; b – (ii), (iv) ; c - (i) ; d – (iii) ; e – (iii), (ii)
• C. a – (ii), (iv) ; b – (ii) ; c - (i) ; d – (iii) ; e – (iii), (ii)
• D. a – (ii), (iv); b – (ii), (iii) ; c - (i) ; d – (ii) ; e – (ii)

Answer 1

The correct option is D

a – (ii), (iv); b – (ii), (iii) ; c - (i) ; d – (ii) ; e – (ii)

In plants like cacti, various types of modifications can be observed. To prevent the loss of water, many modifications are done. Leaves are modified into thorns. This reduces the surface area and hence water loss by transpiration. The stems become large and succulent. i.e. they become fleshy and store water. So the green part we see in cacti are stems. The stomata present in this part of the plant are also closed during the day to prevent loss of water. Loss of water is also prevented by storing carbon dioxide at night. To take carbon dioxide inside the cells, each cell has to give out water in the form of water vapour. The root system of cacti is well developed and roots go deep into the soil in search of water.