Question

Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells? a)Secretion of granzyme b)Recognition of infected host cell using its TCR c) Secreting antibody specific against the pathogen. d) Secretion of perforin.

Answer 1

Cytotoxic T cells do not secrete antibodies; they kill infected cells using recognition by TCR, secretion of granzyme, and secretion of perforin. The correct step not used by cytotoxic T cells is 'Secreting antibody specific against the pathogen.'

Step-by-step explanation:

The correct answer to the student's question is option (c): Secreting antibody specific against the pathogen. Cytotoxic T cells, also known as CD8+ T cells, have several mechanisms for killing infected host cells, which include:

• Recognition of infected host cells using its TCR (T-cell receptor)
• Secretion of granzyme, which are enzymes that induce apoptosis (programmed cell death) in the infected cells
• Secretion of perforin, a protein that creates pores in the target cell, allowing granzymes to enter

However, cytotoxic T cells do not secrete antibodies; this function is carried out by B cells during the humoral immune response.

Answer 2

The correct answer is C

Step-by-step explanation:

Cytotoxic cells are lymphocytes that kills or destroy cancerous cells, infected cells especially the one infected with virus, and damaged cells.

Cytotoxic cells does not secret antibodies to fight pathogens but the secret granzyme and perforin to kills infected cells.

They recognised their host cells by using their T cell receptors(TCR).