Root hair absorbs water from soil through

• turgor pressure

• ion exchange

• osmosis

• DPD

Who said that 'transpiration is a necessary evil'

• Curtis

• Andersen

• Steward

• J.C. Bose

153.

Transpiration would be lowest when

• wind velocity is high

• enough water is in the soil

• atmospheric RH is high

• high temperature and light

Which of the following exhibits a direct porportionality to transpiration

• Light and RH

• Temperature and RH

• Temperature and wind

• RH and wind

Water in plants is transported by

• cambium

• phloem

• xylem

• epidermis

The most important force which pulls water up in tall trees is

• imbibition force

• osmotic force

• cohesive force

• electromagnetic force

The light phase of photosynthesis is called

• Hill reaction

• photo action

• pigment action

• chlorophyllous process

Potometer works on the principle of

• amount of water absorbed equals the maount transpired

• osmotic pressure

• root pressure

• potential difference between the tip of the tube and that of the plant

Which one of the following does'nt help in molecule transport?

• Diffusion

• Osmosis

• Surface tension

• Active transport

Potometer is used to measure

• ascent of sap

• root pressure

• transpiration

• photosynthesis