Question

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

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

Choose the correct option that matches correctly. There can be multiple matches.

• 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 cacti, various types of modifications can be observed to prevent the loss of water. 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. The stomata present on this part of the plant are also kept 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.