Following statements are regarding to double fertilization in angiosperms.

A. One sperm cell fuses with the egg cell to produce the zygote that will develop into the new embryonic plant.

B. The second sperm cell fuses with the usually binucleate central cell, giving rise to the

endosperm, the tissue that nourishes the developing embryo. This second event is not “true” fertilization in the sense of male and female gametes undergoing fusion.

C. The second sperm cell fuses with the usually binucleate central cell, giving rise to the

endosperm, the tissue that nourishes the developing embryo. This second event is “true” fertilization in the sense of male and female gametes undergoing fusion.

D. During fertilization in angiosperm, when the sperm cells are released, the egg undergoes a flux of Ca2+. Then, chemicals released from the egg appear to make the sperm competent for cell fusion.

Which of the following statements are true?

TLS Online TPP Program

#Question id: 1581

#Unit 4. Cell Communication and Cell Signaling

An otherwise healthy student in your class is infected with EBV, the virus that causes infectious mononucleosis. The same student had already been infected when she was a child, and she had merely experienced a mild sore throat and swollen lymph nodes in her neck. This time, though infected, she does not get sick. 

Her immune systemʹs recognition of this infection will involve which of the following?

TLS Online TPP Program

#Question id: 1582

#Unit 4. Cell Communication and Cell Signaling

The EBV antigen fragments will be presented by the virus-infected cells along with which of the following?

TLS Online TPP Program

#Question id: 1583

#Unit 4. Cell Communication and Cell Signaling

These cells are involved in cell-mediated immunity and destroy virally infected cells:

TLS Online TPP Program

#Question id: 1584

#Unit 4. Cell Communication and Cell Signaling

Which cell type interacts with both the humoral and cell-mediated immune pathways?

TLS Online TPP Program

#Question id: 16957

#Unit 4. Cell Communication and Cell Signaling

the immune system can be summarized as follows. Which is not correct for immune system?

TLS Online TPP Program

#Question id: 16956

#Unit 4. Cell Communication and Cell Signaling

Polyclonal antibodies are raised against bovine serum albumin in rabbit. Subsequently IgG in the antiserum is purified and digested with either pepsin or papain. Out of the following possibilities, which one is correct?