The edges of each base pair are exposed in the major and minor grooves, creating a pattern of hydrogen-bond donors and acceptors and of hydrophobic groups (allowing for Vander Waals interactions) that identifies the base pair. The edge of an C : G base pair displays the following chemical groups in the following order in the major groove:

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#Question id: 34118

#Unit 2. Cellular Organization

A. Trypsin treated core histones quickly forms 30-nm fibers

B. Core histones lacking their amino-terminal tails are incapable of forming 30-nm fibers

C. Interaction between the positively charged amino terminus of histone H4 and a negatively charged region of the histone-fold domain of histone H2A is particularly important for 30-nm fiber formation

D. H2A that interact with the H4 tail are conserved across many eukaryotic organisms but are not involved in DNA binding or formation of the histone octamer.

Choose true and false

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#Question id: 34119

#Unit 2. Cellular Organization

30-nm fiber forms loops of 40–90 kb that are held together at their bases by a proteinaceous structure referred to as the nuclear scaffold. These are stabilised by

TLS Online TPP Program

#Question id: 34120

#Unit 2. Cellular Organization

The dynamic nature of DNA binding to the histone core structure is important, because many DNA-binding proteins strongly prefer to bind to histone-free DNA. Such proteins can recognize their binding site only when it is released from the histone octamer or is contained in linker or nucleosome-free DNA.

Which of the following statement stands untrue for above fact

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#Question id: 34121

#Unit 2. Cellular Organization

Replication independent assembly of histones is catalysed by

TLS Online TPP Program

#Question id: 34122

#Unit 7. System Physiology – Animal

Loss of which of the following pituitary hormones might be expected to increase responses to painful stimuli?

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#Question id: 34123

#Unit 7. System Physiology – Animal

A neuroscientist is studying communication between the hypothalamus and pituitary in a rat model. She interrupts blood flow through the median eminence and then measures circulating levels of pituitary hormones. Secretion of which of the following hormones will be unaffected by the experimental manipulation?