Limited renewal of adult stem cells may contribute to aging..

TLS Online TPP Program

#Id: 9792

#Unit 6. System Physiology – Plant

Effect of light is Photomorphogenesis

 A decrease in the rate of stem elongation

The beginning of apical-hook straightening

The initiation of the synthesis of pigments

TLS Online TPP Program

#Id: 9793

#Unit 6. System Physiology – Plant

TLS Online TPP Program

#Id: 9794

#Unit 6. System Physiology – Plant

Phytochromes are photoreceptors that absorb red and far-red light most strongly (600–750 nm)

they also absorb blue light (350-500 nm) and UV-A radiation (320–400 nm).

TLS Online TPP Program

#Id: 9795

#Unit 6. System Physiology – Plant

The amount of light is referred to as the fluence, which is defined as the total number of photons impinging on a unit surface area. Total fluence = fluence rate × the length of time

TLS Online TPP Program

#Id: 9796

#Unit 6. System Physiology – Plant

Bacterial phytochrome-like proteins (BphPs) regulate the biosynthesis of the photosynthetic apparatus in Rhodopseudomonas

TLS Online TPP Program

#Id: 9797

#Unit 6. System Physiology – Plant

In dark-grown or etiolated plants, phytochrome is present in a red light–absorbing form, referred to as Pr. Pr, which to the human eye is blue, is converted by red light to a far-red light–absorbing form called Pfr, which is blue-green.