The processes by which the three ectodermal regions are made physically and functionally distinct from one another is called neurulation. Following statements are regarding to the mechanism of neurulation.

A. The specification of the ectoderm is accomplished during gastrulation, primarily by regulating the levels of BMP experienced by the ectodermal cells.

B. High levels of BMP specify the cells to become neural plate.

C. Very low levels specify the cells to become epidermis.

D. Intermediate levels effect the formation of the neural crest cells.

Which of the following combination is correct?

TLS Online TPP Program

#Question id: 4490

#Unit 3. Fundamental Processes

The human immunodeficiency virus (HIV), which causes AIDS, transcribes its genes from a promoter controlled by P-TEFb (and SEC). Again, polymerase initiates transcription at that promoter, under the control of which activator?

TLS Online TPP Program

#Question id: 4491

#Unit 3. Fundamental Processes

HIV transcribes its genes from a promoter controlled by P-TEFb, P-TEFb is brought to the stalled polymerase by an RNA-binding protein, not a DNA-bound one. The protein responsible is called

TLS Online TPP Program

#Question id: 4492

#Unit 3. Fundamental Processes

If an enhancer activates a specific gene 400 kb away, what stops it from activating other genes whose promoters are within that range?

TLS Online TPP Program

#Question id: 4493

#Unit 3. Fundamental Processes

An insulator is placed between the enhancer and the promoter, When bound by insulator-binding protein CTCF,

TLS Online TPP Program

#Question id: 4494

#Unit 3. Fundamental Processes

Propagation of certain repressing histone modifications over stretches of chromatin lies at the heart of a phenomenon is known,

TLS Online TPP Program

#Question id: 4495

#Unit 3. Fundamental Processes

_ elements can block this spreading, protect genes from both indiscriminate activation and repression.