Concept explainers
A single bacterium has _______ epitope(s).
- a. a specific
- b. multiple
- c. MHC
- d. clonal
Introduction:
The capacity of a lymphocyte to distinguish the difference between molecular shapes is so sensitive that it can recognize and respond to only a specific portion of an antigenic molecule. This fragment of the molecule is known as an epitope.
Answer to Problem 1Q
Correct answer:
A single bacterium has multiple epitopes. Therefore, option (b) is correct.
Option (b) is given as “multiple”.
Explanation of Solution
Justify the reason for the correct statement:
The epitope is an antigenic determinant fragment of an antigenic molecule. This is recognized by the immune system. It is the specific portion of antigen molecules and a single antigenic molecule carries multiple epitopes. Paratope is the portion of an antibody that binds to the antigenic epitope and trigger an immune response such as phagocytosis.
Hence, option (b) is correct.
Justify the reasons for the incorrect statements:
Option (a) is given as “a specific”.
Many epitopes are present on antigen molecules that generate specific immunity. Hence, it is a wrong answer.
Option (c) is given as “MHC”.
MHC stands for “major histocompatibility complex”. It is a surface marker that helps presentation of the pathogenic epitope to the T-cells. Hence, it is a wrong answer.
Option (d) is given as “clonal”.
Foreign antigen activates B or T cells that are appropriate (correct) for it by the mechanism of clonal selection. Hence, it is a wrong answer.
Hence, options (a), (c), and (d) are incorrect.
Multiple epitopes are found on a single bacterium.
Want to see more full solutions like this?
Chapter 13 Solutions
MICROBIOLOGY FUNDAMENTALS (LOOSELEAF)
- Activated complement proteins ________. a. puncture cells c. attract macrophages b. promote inflammation d. all of the abovearrow_forwardAntibodies are ________. a. antigen receptors c. proteins b. made only by B cells d. all of the abovearrow_forwardThe humoral immune response depends on which cells? a. TC cells b. B cells c. B and TH cells d. TC and TH cellsarrow_forward
- Hybridomas are formed by fusing antibody-producingwhite blood cells with:(a) Viruses(b) Bacteria(c) Myeloma cells(d) Red blood cells(e) Bone marrow cellsarrow_forwardSuppose a person recovers normally from viral infections, but then gets the same viral infections over and over again- unlike the rest of us. A. What is probably wrong –B cells, helper T cells and/or cytotoxic T cells? B. Should this person be at a higher risk of cancer than the rest of us? C. Should this person be able to lyse bacterial cells as well as the rest of us? D. Should this person tolerate a graft (from an unreated person) better than you are me?arrow_forwardThe complement system of defense is composed of proteins that are always present in the blood. Which statement describes the importance of this system in early pathogen defense? A.) It does not have to be activated by antibodies. B.) It rapidly lower the blood pH. C.) It recognizes specific common pathogens. D.) It causes immediate pathogen lysis.arrow_forward
- An allergic reaction is an example of: a) the immune system not working at all. b) a deficiency of B cell responses. c) the immune system doing its job too well. d) an overabundance of T cell responses.arrow_forwardThe humoral immune response depends on which cells? a. TC cells b. B cells c. B and TH cells d. TC and TH cellsarrow_forwardAn antigen-presenting cell (APC)a. presents antigens to T cells.b. secretes antibodies.c. marks each human cell as belonging to that person.d. secretes cytokines only.arrow_forward
- Immunoglobins help eliminate the pathogen through the process of: A. Release of hydrolytic enzymes on the pathogen B. Agglutination and precipitation C. Direct phagocytosis D. Activating plateletsarrow_forwardAfter his recovery from chickenpox, which lymphocytes will keep this patient from becoming infected again? A) T helper cells B) Natural killer cells C) T memory cells D) B cellsarrow_forwardWhy is the secondary immune response so much stronger than theprimary response?a. Because high concentrations of antibodies are already presentb. Because the phagocytes present the antigens more rapidlyc. Because memory B cells can rapidly convert to plasma cellsd. Because protein synthesis occurs more quickly in memory cellsarrow_forward
- Medical Terminology for Health Professions, Spira...Health & NutritionISBN:9781305634350Author:Ann Ehrlich, Carol L. Schroeder, Laura Ehrlich, Katrina A. SchroederPublisher:Cengage LearningConcepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College