Which, if any, of the following statements is incorrect?

I. In X-chromosome inactivation, the inactivated X chromosome is epigenetically silenced by a transcript, the XIST RNA, that is produced from the active X chromosome.

II. The XIST RNA works by coating most of the X chromosome that is to be inactivated and then recruiting Polycomb proteins to condense the chromosome.

III. The inactivated X chromosome carries the kinds of histone modification that are typical of heterochromatin.

IV. The pattern of X-chromosome inactivation is made randomly but once it has been established the same pattern of X-inactivation is propagated through all mitotic and meiotic cell divisions.

#Question id: 10931

#Unit 7. System Physiology – Animal

A 24-year-old African-American man comes to the emergency room 3 hr after the onset of severe back and chest pain. These problems started while he was skiing. He lives in Los Angeles and had a previous episode of these symptoms 5 years ago while visiting Wyoming. He is in obvious pain. Laboratory studies show the following:

Hemoglobin                                        11 gm/dl

Leukocyte count                                 22,000/μl3

Reticulocyte count                              25%

What is the diagnosis of this patient?

#Question id: 10932

#Unit 7. System Physiology – Animal

A 62-year-old man complains of headaches, visual difficulties, and chest pains. His examination shows a red complexion and a large spleen. His complete blood count follows: hematocrit, 58%, WBC 13,300/μl, and platelets 600,000/μl. His arterial oxygen saturation is 97% on room air. Which of the following would you recommend as a treatment?

#Question id: 10933

#Unit 1. Molecules and their Interaction Relevant to Biology

Imidazole ring is the characteristic of which amino acid

#Question id: 10934

#Unit 1. Molecules and their Interaction Relevant to Biology

Carboxy terminus is protonated at ………………while amino terminus will be deprotonated at………..

#Question id: 10935

#Unit 1. Molecules and their Interaction Relevant to Biology

The pH at which imidazole of histidine ring will be protonated………….. and imine group of proline will be deprotonated…………….

#Question id: 10936

#Unit 1. Molecules and their Interaction Relevant to Biology

Which type of chemical bonds are required to produce an absorption spectrum in UV-visible region? the molecule must contain