That not all of the fragment population represents bona fide Okazaki fragments; some are pseudo fragments that have been generated by breakage in a DNA strand that actually was synthesized as a continuous chain. The source of this breakage is the incorporation of some uracil into DNA in place of thymine. When the uracil is removed by a repair system, the leading strand has breaks until a thymine is inserted. 

TLS Online TPP Program

#Id: 9817

#Unit 6. System Physiology – Plant

Phytochrome responses fall into three major categories based on the amount of light they require: very low fluence responses (VLFRs), low-fluence responses (LFRs), and high-irradiance responses (HIRs).

TLS Online TPP Program

#Id: 9818

#Unit 6. System Physiology – Plant

VLFRs are non-photoreversible.

TLS Online TPP Program

#Id: 9819

#Unit 6. System Physiology – Plant

Arabidopsis seeds can be induced to germinate with red light in the range of 0.001 to 0.1 μmol m–2 at very-low-fluence responses (VLFRs).

TLS Online TPP Program

#Id: 9820

#Unit 6. System Physiology – Plant

LFRs is found at red region (660 nm) and (720 nm) includes processes such as the promotion of lettuce seed germination, inhibition of hypocotyl elongation, and regulation of leaf movements.

TLS Online TPP Program

#Id: 9821

#Unit 6. System Physiology – Plant

A brief pulse of red light will induce a response, provided that the light is sufficiently bright, and conversely, very dim light will work if the irradiation time is long enough. 

This reciprocal relationship between fluence rate and time is known as the law of reciprocity

TLS Online TPP Program

#Id: 9822

#Unit 6. System Physiology – Plant

VLFRs and LFRs both obey the law of reciprocity