Match the following mechanism of polyspermy (Column I) with events (Column II).

Column I	Column II
A. Fast block to polyspermy	i. chemicals from the fusing sperm cytoplasm alter the sodium ion (Na+) channels on the membrane
B. Slow block to polyspermy	ii. enzyme cortical granule serine protease, cleaves the protein posts that connect the vitelline envelope
	iii the concentration of free Ca2+ in the egg cytoplasm increases
	iv. an electric change in the egg cell membrane
	v. the concentration of free Na+ in the egg cytoplasm increases

Which of the following is correct?

TLS Online TPP Program

#Question id: 15450

#Unit 4. Cell Communication and Cell Signaling

T-cell dependent response requires a signal is provided by an activated T cell, which binds to the B cell through,

a) lipopolysaccharide moiety

b) its antigen receptor 

c) A separate interaction between CD40L on the B cell and CD40 (CD154) on the activated TH cell

d) A separate interaction between CD40 on the B cell and CD40L (CD154) on the activated TH cell

TLS Online TPP Program

#Question id: 15449

#Unit 4. Cell Communication and Cell Signaling

Class switch recombination of B-cell that is generated upon recognition of protein antigens and requires the participation of_____

TLS Online TPP Program

#Question id: 15448

#Unit 4. Cell Communication and Cell Signaling

Stimulation of a single B cell would result in the generation of a clone of cells having_____

TLS Online TPP Program

#Question id: 15447

#Unit 4. Cell Communication and Cell Signaling

During development two types of B-cells will be formed:- 

I) T1 cell

II) T2 cell

Some features about T1 and T2 cells given in below;

a) Maturity achieve

b) Found in blood circulation

c) Presence of  Immunoglobulin IgM high and IgD low

d) Expressing CD21 and CD23

e) Cell expressing BAFF-R, Which bind with BAFF survival factor

Match the cell with their correct features;

TLS Online TPP Program

#Question id: 1389

#Unit 4. Cell Communication and Cell Signaling

 Why has C. elegans proven to be a useful model for understanding apoptosis?

TLS Online TPP Program

#Question id: 1390

#Unit 4. Cell Communication and Cell Signaling

Which of the following statements describes the events of apoptosis?