General physiology Qs

 

21. The permeability of lipid soluble particle is proportional to their

A) Molecular size

B) Molecular shape

C) Molecular charge

D) Lipid solubility

Ans: D

22.Michaelis-Menten –Kinetics means

A) Movement of particles from high concentration to low concentration

B) Osmotic kinetics

C) Saturation kinetics

D) Solvent drag

Ans: C

Explanation:

Saturation kinetics occurs in facilitated diffusion where the rate of diffusion rises as the concentration gradient increases until all the binding sites on the carrier proteins are utilized. At this point the rate of

diffusion can no longer rise with increasing particles concentration.

23. Colligative property of solution depends upon

A) the molecular weight of the substance

B) the size and shape of the substance

C) the ratio of the number of solute to the number of solvent molecules

D) the charge of the molecule

Ans: C

24. Transcrption means

A) DNA replication

B) Convertion of m-RNA to protein

C) formation of nucleosome

D) DNA sequence is copied into RNA for gene expression

Ans: D

25.Na⁺ - K⁺ ATPase

A) transport 3K ⁺ out of the cell in exchange of 2Na ⁺ into the cell

B) transport 3Na ⁺ out of the cell in exchange of 2K ⁺ into the cell

C) transport 2Na ⁺out of the cell in exchange of 2K  ⁺ into the cell

D)  transport 1Na ⁺out of the cell in exchange of 1K  ⁺into the cell

Ans: B

26. Apoptosis means

A) Formation of new cells

B) Phagocytosis

C) Programmed cell death

D) Cell death due to an acute injury

Ans: C

27.Na⁺  - K⁺ ATP ase pumping activity increases approximately in

A) proportion to the 3^rd power of intracellular K⁺ concentration

B) Proportion to the 3^rd power of intracellular Na⁺ concentration

C)  Proportion to the 4^rth power of intracellular K⁺ concentration

D)   Proportion to the 4^rth power of intracellular Na⁺ concentration

Ans: B

28. Absolute refractory period for large myelinated nerve fiber is about

A) 1/25 sec

B)1/250 sec

C)1/1000sec

D)1/2500 sec

Ans: D

29. Local circuit of current flow in myelinated nerve fiber occurs in

A) thick myelin sheath

B) one node of Ranvier to next

C) insulated regions

D) Schwann cell

Ans: B

30. maximum strength of contraction occurs when the sarcomere length is

A) 2.2µm

B)3.5µm

C)4.5µm

D)1.5µm

Ans: A

Explanation: At 2.2µm length, there is optimal degree of overlapping and greater force development.

At greater lengths, the actin filament has pulled out to the end of myosin. So, no actin-myosin overlap. Decreased length decreases the force of contraction, because the 2 Z discs of the sarcomere abut the ends of myosin filaments

 

 

diffusion can no longer rise with increasing particles concentration.