A tadpole resembles a fish and breathes through external gills. Adult frogs breathe through their lungs and exchange gases through their skin and the lining of their mouths.

Correct Option: B

A tadpole resembles a fish and breathes through external gills. Adult frogs breathe through their lungs and exchange gases through their skin and the lining of their mouths.

According to the K+ ion theory the guard cells absorb K+ ions from the cells around them as they produce ATP (due to photosynthesis) and become hyper-tonic. This leads to absorption of water from nearby cells by endosmosis due to which the guard cells become turgid and the stomata opens. Decreasing light intensity and photosynthesis causes Stomatal closing.

Correct Option: B

According to the K+ ion theory the guard cells absorb K+ ions from the cells around them as they produce ATP (due to photosynthesis) and become hyper-tonic. This leads to absorption of water from nearby cells by endosmosis due to which the guard cells become turgid and the stomata opens. Decreasing light intensity and photosynthesis causes Stomatal closing.

Guard cells are dumb-bell shaped in monocots such as wheat. The central portion of the guard cells in wheat is narrow and two ends are bulbous. Guard cells are surrounded by adjacent subsidiary cells.

Correct Option: C

Guard cells are dumb-bell shaped in monocots such as wheat. The central portion of the guard cells in wheat is narrow and two ends are bulbous. Guard cells are surrounded by adjacent subsidiary cells.

The guard cells in dicot plants are kidney shaped and dumbbell shaped in monocots. When guard cells expand on the outer edges of the stoma, but not on the inner side, they result in kidney-shaped cells, leading to an opening or pore between the two guard cells for gas exchange.

Correct Option: A

The guard cells in dicot plants are kidney shaped and dumbbell shaped in monocots. When guard cells expand on the outer edges of the stoma, but not on the inner side, they result in kidney-shaped cells, leading to an opening or pore between the two guard cells for gas exchange.

There are three meristematic layers in plants which consist of three sets of initials known as histogen. Dermatogen is the outermost layers, the cells of which divide anticlinally and give rise to the epidermis. Periblem and Plerome are the other two histogen.

Correct Option: A

There are three meristematic layers in plants which consist of three sets of initials known as histogen. Dermatogen is the outermost layers, the cells of which divide anticlinally and give rise to the epidermis. Periblem and Plerome are the other two histogen.