In very dry soils, the water potential (Yw) may fall below what is called the permanent wilting point, the water potential of the soil is so low that plants cannot regain turgor pressure even if all water loss through transpiration ceases. This means that

a) The hydraulic conductivity decreases drastically 

b) The water potential of the soil (Yw) is less than or equal to the osmotic potential (Ys ) of the plant

c) The water potential of the soil (Yw) is more than the osmotic potential (Ys) of the plant

d) cell osmotic potential (Ys) varies with plant species, the permanent wilting point is clearly not a unique property of the soil, it depends on the plant species

TLS Online TPP Program

#Question id: 10420

#Unit 6. System Physiology – Plant

 A toggle model has been proposed for phytochrome interconversion, according to this model which option is correct?

TLS Online TPP Program

#Question id: 10421

#Unit 6. System Physiology – Plant

The red light-induced rotation of the D ring of the chromophore causes the hairpin to become helical, which of the following β-hairpin changes conformation after rotation?

TLS Online TPP Program

#Question id: 10422

#Unit 6. System Physiology – Plant

Arabidopsis contains five genes encoding phytochromes, PHYA–PHYE, four of the five phytochromes appear mostly light-stable in the plant and function primarily in the regulation of LFRs and of shade avoidance involving changes in the R:FR ratio.

TLS Online TPP Program

#Question id: 10423

#Unit 6. System Physiology – Plant

Which of the following responses include processes such as the promotion of lettuce seed germination, inhibition of hypocotyl elongation, and regulation of leaf movements?

TLS Online TPP Program

#Question id: 10424

#Unit 6. System Physiology – Plant

Phytochrome responses fall into three major categories based on the amount of light they require, which one is not the category of phytochrome responses;

TLS Online TPP Program

#Question id: 10425

#Unit 6. System Physiology – Plant

Very low fluence responses such as 0.0001 µmol m–2 reach a maximum at about 0.05 µmol m–2, on these fluence rate red light induce phytochrome responses. Which of the following is not the phytochrome responses on VLFR