Multiple Choice Questions

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Chemosensitive area of respiratory centre in medulla is affected by

  • less CO2 and H+ ions

  • less O2 and Hions

  • excess CO2 and H+ ions

  • excess O2 and Hions


C.

excess CO2 and H+ ions

Respiratory rhythm centre is a specialised centre present in the medulla region of the brain responsible for its regulation. A chemosensitive area is situated adjacent to the rhythm centre which is highly sensitive to CO2 and H+ ions. Increase in these substances can activate this centre and in turn can signal the rhythm centre to make necessary adjustments in the respiratory process.


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The taxon which includes related species is

  • class

  • order

  • family

  • genus


Which one is correct regarding electrocardiograph (ECG)?

  • P- wave represents the electrical excitation of the ventricle.

  • QRS complex represents repolarisation of the ventricles

  • T- wave represents repolarisation of the atria

  • By counting the number of QRS complexes one can determine the pulse rate


What is the effect of GnRH produced by hypothalamus?

  • Stimulates the synthesis and secretion of androgens

  • Stimulates secretion of milk in mammary glands

  • Stimulates foetal ejection reflex

  • Stimulates synthesis of carbohydrates from non- carbohydrates in liver


Animals take phosphorus from

  • water

  • plants

  • rock

  • soil


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Which of the following have porous body and are diploblastic?

  • Aurelia and Obelia

  • Adamsia and Euplectella

  • Leucosolenia and Spongilla

  • Sycon and Hydra


Microvilli of intestinal epithelium are similar in function with 

  • typhlosole in earthworm

  • hepatic caecae in cockroach

  • intestinal caecum in earthworm

  • Malpighian tubules in coackroach


The type of epithelial cells which line the inner surface of Fallopian tubes, bronchioles and bronchi are known as

  • squamous epithelium

  • ciliated epithelium

  • columnar epithelium

  • cubical epithelium


Cyclic photophosphorylation involves

  • PS I

  • PS II

  • PS I and PS II

  • P680


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What are Singer and Nicolson known for?

  • One-gene-one-enzyme hypothesis

  • Plasma membrane modifications

  • Fluid-mosaic model of plasma membrane

  • Structure of DNA