In a normal human eye, for sharp image formation on the retina, maximum dioptric power is provided by the

• Retina

• Cornea

• Anterior surface of the lens  

• Posterior surface of the lens  

In this flow diagram name the chemicals A, B, C and D in proper sequence.

• Renin, Angiotensin II, Angiotensis I, Angiotensinogen 

• Angiotensin I, Angiotensinogen, Angiotesin II, Renin   

• Renin, Angiotensin I, Angiotensin II, Angiotensinogen     

• Renin, Angiotensinogen, Angiotensin I, Angiotensin II   

The decision to become either a trophoblast or inner cell mass blastomere is one of the first decisions taken by any mammalian embryo. Below is a diagrammatic representation of the different cells formed during development from the morula with the help of different molecules. Identify the molecules 1-4 sequentially.

• Cdx 2,Oct 4, Nanog, Stat 3 

• Cdx 2, Nanog, Stat 3, Oct 4 

• Cdx 2, Nanog, Oct 4, Stat 3 

• Cdx 2, Oct 4, Stat 3, Nanog 

24.

With respect to the extra embryonic structures formed in the mammals, the possible functional attributes have been designated:

A. Allantoin stores urinary waste and helps mediate gas exchange. It is derived from splanchnopleure at the caudal end of the primitive streak.

B. Amnion is a water sac and protects the embryo and its surrounding amniotic fluid. This epithelium is derived from somatopleure.

C. Chorian is essential for gas exchange in amniote embryos. It is generated from the splanchnopleure.

D. Yolk sac is the last embryonic membrane to form and is derived from somatopleure.

Which of the above statements are correct?

• A and B

• A and C

• B and C

• A and D

The figure above represents a late zebrafish gastrula. The following concepts may be proposed during further development of the embryo.

A. The concentration of FGF decreases from the yolk towards the epidermis, along with the increase of BMP activity from the dorsal to the ventral axis.

B. Increase in FGF activity in the epidermis with concomitant decrease in BMP activity towards the ventral axid.

C. Neural induction in zebrafish is independent of the organizer and depends on activation of BMP signaling.

D. In comparison, both Xenopus and chick embruos require activation of FGF for neural induction to occur in addition to BMP inhibition.

Which of the above statements are true?

• A and C

• B and C

• A and D

• C and D

An isolated carotid sinus was prepared so that the pressure may be regulated by a pump the resulting discharge in single carotid sinus nerve fibre could be recorded. The following are the possible observations

A. No discharge when carotid sinus perfusion pressure was below 30 mm Hg.

B. Linear increase in discharge frequently when carotid sinus perfusion pressure was gradually increased from 70 to 110 mm Hg.

C. Increase in discharge frequency was more prominent in greater pulsatile changes of carotid sinus pressure keeping the mean pressure identical in all cases.

D. Increase in discharge was more prominent in a falling phase of pulsatile change of carotid pressure than in the rising phase.

Which one of the following is correct?

• A, B and C

• A and C

• B and D 

• Only D

For a normal heart, the time taken for atrial systole and diastole are A_S and A_D seconds respectively, while the same for ventricular systole and diastole are V_S and V_D. Which one of the following equations is correct?

• A_S + A_D = V_S + V_D

• A_S + A_D < V_S + V_D    

• A_S + A_D = V_S + V_D – 0  

• A_S + A_D > V_S + V_D    

During the Spanish conquest of the Inca Empire at the high altitude in Peru, many soldiers fell sick. It was found that the sickness was due to low partial pressure of O₂ in the atmosphere at that altitude. To determine the reason, blood was collected from those patients. The circulating arythropoietin (EPO) level were estimated and the O₂-dissociation curve of haemoglobin were drawn and compared with the same in native people as depicted below.

Which one of the following combinations is logically correct?

• A and C  

• A and D

• B and C

• B and D

A monkey undergoes cerebellectomy. After the post-operative recovery, the monkey was given a task to press a bar. The possible observations are:

A. Its hand would overshoot the target while reaching the bar.

B. It would be unable to move forelimbs.

C. It would show intention tremor while trying to press the bar.

D. It would press the bar with mouth instead of hand.

Which one of the following is correct?

• A and C

• B only

• D only

• B and D

A 1 meter tall object was placed 10 meter in front of a normal eye. The size of the image on the retina will be (consider distance between lens and retina = 1.7 cms)

• 0.17 mm

• 1.7 mm

• 3.4 mm

• 170µm