NEET BIOLOGY

Detailed explanation-1: -The pit membrane, consisting of a modified primary cell wall and middle lamella, lies at the center of each pit, and allows water to pass between xylem conduits while limiting the spread of air bubbles (i.e., embolism) and xylem-dwelling pathogens.

Detailed explanation-2: -The two primary vascular tissues are xylem, which transports water and dissolved minerals from the roots to the leaves, and phloem, which conducts food from the leaves to all parts of the plant.

Detailed explanation-3: -The major driving force for transport of water through xylem in plants during the day is transpiration which creates transpiration pull and during the night is root pressure due to the absence of transpiration.

Detailed explanation-4: -Plants absorb water through their entire surface – roots, stems and leaves. However, the majority of water is absorbed by root hairs. Root hairs are thin-walled uni-cellular outgrowths of epidermis.

Detailed explanation-5: -Xylem is responsible for the transport of water and dissolved ions from the roots upwards through the plant.