Question 1

When an antigen binds to the antibody in the membrane of a B cell, the B cell proliferates and forms a population of B lymphocytes that all make the same antibody. The population of B lymphocytes thus formed is called ________.
A)a group
B)a clone
C)an identicon
D)a proliferate
E)a codon

Accepted Answer

The population of B lymphocytes formed from a single B cell that all make the same antibody is called a clone.

Question 2

What cellular structure is found to be greatly expanded in plasma cells, but not in their precursor cells?
A)nuclei
B)mitochondria
C)chloroplasts
D)rough endoplasmic reticulum
E)lysosomes

Accepted Answer

Plasma cells have a greatly expanded rough endoplasmic reticulum, which allows for the high rate of protein synthesis necessary for the production and secretion of antibodies. This expansion is not seen in their precursor cells.

Question 3

The foreign molecules that stimulate the adaptive immune system to make antibodies are called ________.
A)integrins
B)antigens
C)antibodies
D)thrombins
E)albumins

Accepted Answer

Foreign molecules that stimulate the adaptive immune system to make antibodies are called antigens. Integrins are proteins that participate in cell adhesion and signaling. Antibodies are proteins produced by the immune system that specifically bind to antigens. Thrombins are enzymes that play a role in blood clotting. Albumins are proteins that help regulate osmotic pressure in the body.

Question 4

Which of the following models for the induction of antibodies was proposed initially by Niels Jerne?
A)The body makes small amounts of randomly structured antibodies in the absence of any antigen; exposure to an antigen leads to the production of the corresponding antibody.
B)Antibodies are ingested from food and stored in the body until exposed to corresponding antigens.
C)Antibodies are molded over the surface of antigens.
D)Antibodies are reverse engineered from the DNA of bacterial pathogens

Accepted Answer

Niels Jerne initially proposed the natural selection theory, which suggests that the body produces a wide variety of antibodies randomly, and when an antigen is encountered, the corresponding antibody is then produced in larger amounts.

Question 5

Some activated B cells remain in lymphoid tissue and respond rapidly at a later date if the antigen reappears in the body. Such cells are called __________.
A)memory B cells
B)activation B cells
C)plasma cells
D)secretion cells
E)antibody-producing cells

Accepted Answer

Memory B cells are specifically involved in the adaptive immune response and act as a type of immune cell that remembers previously encountered pathogens and can rapidly respond to subsequent exposures. This feature allows for a more efficient and effective immune response upon reinfection.

Question 6

When does the full repertoire of antibody-producing cells (all such cells that a person will ever have)appear in the lymphoid tissue?
A)in the fertilized egg
B)before stimulation by an antigen
C)before stimulation by an antibody
D)after stimulation by all of the possible antibodies
E)after stimulation by any of the possible antigens

Accepted Answer

The full repertoire of antibody-producing cells is generated through a process called V(D)J recombination, which occurs in developing lymphocytes before stimulation by any antigen or antibody. This process rearranges gene segments within the lymphocyte's DNA to generate a diverse set of antibody-producing cells. Therefore, the correct answer is B, before stimulation by an antigen.

Question 7

Which immune system component is found in plants but NOT vertebrates?
A)pattern recognition receptors
B)PAMP receptors
C)PRRs
D)NLRs

Accepted Answer

NLRs (Nucleotide-binding Leucine-rich Repeat receptors) are a type of immune receptor found in plants that are not present in vertebrates.

Question 8

What immune system organ is located in the chest, is responsible for the differentiation of T cells, and reaches its peak size during childhood?
A)the thyroid gland
B)the adrenal gland
C)the thymus gland
D)the lymph nodes
E)the liver

Accepted Answer

The thymus gland is located in the chest, is responsible for the differentiation of T cells, and reaches its peak size during childhood. The thyroid gland regulates metabolism, the adrenal gland produces hormones such as adrenaline, the lymph nodes filter lymph fluid, and the liver is responsible for detoxification and protein synthesis, but none of these organs fit the description given in the question.

Question 9

What allows so many different antibodies to be made by the immune system?
A)because mistakes are made during DNA replication
B)because mistakes are made during transcription
C)because mistakes are made during reverse transcription
D)because thousands of different DNA rearrangements are possible
E)because thousands of different mRNA alterations are possible

Accepted Answer

The reason so many different antibodies can be made by the immune system is due to the fact that there are thousands of different DNA rearrangements that can occur. This genetic diversity allows for the production of a wide range of antibodies to recognize and bind to different foreign substances.

Question 10

Which of the antigens below are typically able to activate B cells without the involvement of T cells?
A)very large bacterial lipids
B)very large viral lipids
C)bacterial cell wall polysaccharides
D)bacterial cell wall polypeptides
E)bacterial DNA

Accepted Answer

Bacterial cell wall polysaccharides are known to activate B cells without the involvement of T cells. This is because these antigens have repeating sugar structures that can cross-link multiple B cell receptors, leading to B cell activation.

Question 11

Sensing of pathogen effector proteins by plant cells can lead to all of the following defensive responses EXCEPT:
A)regulating the levels of plant immune defenses through NLR activities
B)production of intracellular proteins called nucleotide binding domain leucine-rich repeat containing receptors (NLRs)
C)production of oxygen radicals
D)production of NK cells

Accepted Answer

Production of NK cells is not a defensive response in plants but a response in animal immune systems. The other options (A, B, and C) are all possible defensive responses that can occur in plant cells upon sensing of pathogen effector proteins.

Question 12

Who realized that a cowpox infection at an early age protected people against deadly smallpox infections?
A)Gregor Mendel
B)Edward Jenner
C)Claude Bernard
D)Louis Pasteur

Accepted Answer

Edward Jenner realized that a cowpox infection at an early age protected people against deadly smallpox infections. He used this observation to develop the first vaccine by inoculating people with cowpox to protect them against smallpox.

Question 13

PAMP-triggered immunity in plants can activate over 1,000 genes in Arabidopsis via _________________ -mediated stimulation.
A)calcium ion
B)protein kinase
C)signal transduction
D)single transcription factor

Accepted Answer

PAMP-triggered immunity in plants activates a signaling cascade through signal transduction pathways, which results in the activation of over 1,000 genes in Arabidopsis. This ultimately leads to the plant's defense response against potential pathogens. Calcium ion, protein kinase, and single transcription factors are all involved in the signal transduction pathway but are not solely responsible for activating over 1,000 genes. Therefore, the best choice is C - signal transduction.

Question 14

What is usually required for B cell activation by an antigen?
A)other B cell interactions
B)T cell activity
C)platelets
D)megakaryocytes
E)erythrocytes

Accepted Answer

B cell activation by an antigen usually requires T cell activity, specifically through the mechanism of T cell-dependent activation. This involves the binding of the antigen to a B cell receptor, processing and presentation of the antigen to a T cell, and subsequent activation of the B cell by T cell-derived cytokines. Other B cell interactions, platelets, megakaryocytes, and erythrocytes are not typically involved in this process.

Question 15

_________ are capable of stimulating immunity but are genetically modified so that they are unable to cause disease.
A)Autistic pathogens
B)Paralysed pathogens
C)Attenuated pathogens
D)Dystrophied pathogens
E)Disadvantaged pathogens

Accepted Answer

Attenuated pathogens are live pathogens that have been modified so that they are unable to cause disease but are still capable of stimulating the immune system to create an immune response. These modified pathogens are used in vaccines to provide immunity against the disease without actually causing the disease itself.

Question 16

What events lead to a differentiating B cell becoming committed to producing only one species of antibody molecule?
A)protein rearrangements in the genome
B)RNA rearrangements in the genome
C)DNA rearrangements in the genome
D)DNA rearrangements in the mitochondrion
E)spontaneous production of proteins in the Golgi complex

Accepted Answer

Differentiation of B cells involves somatic recombination of genetic elements that encode for the variable regions of the antibody molecule. This process, known as V(D)J recombination, involves DNA rearrangements in the genome to generate a unique combination of V, D, and J gene segments. The specific combination of gene segments that are brought together determines the specificity of the B cell receptor, which eventually leads to the production of a single species of antibody molecule. Therefore, option C (DNA rearrangements in the genome) is the correct answer.

Question 17

Some activated B cells differentiate into short-lived cells that secrete large amounts of antibodies. Such cells are called __________.
A)memory cells
B)activation cells
C)plasma cells
D)secretion cells
E)antibody-producing cells

Accepted Answer

The description matches that of plasma cells, which are specialized cells that secrete large amounts of antibodies and have a short lifespan. Memory cells are long-lived cells that can quickly produce large amounts of antibodies upon re-exposure to an antigen. Activation cells, secretion cells, and antibody-producing cells are not commonly used terms in immunology.

Question 18

What happens to plasma cells after the removal of the original antigenic stimulus?
A)They die off.
B)They may, in some cases, persist for the person's lifetime.
C)They revert to precursor cells.
D)They proliferate even more.
E)They dedifferentiate.

Accepted Answer

Plasma cells die off after the removal of the original antigenic stimulus because they are no longer needed to produce antibodies.

Question 19

Genes encoding antibodies are generated by a process in which DNA segments are _______ combined.
A)randomly
B)purposely
C)slowly
D)rapidly
E)incompletely

Accepted Answer

The process of generating genes encoding antibodies involves the random combination of DNA segments. This process is known as V(D)J recombination, and it occurs during the development of B cells in the immune system. The random combination of segments allows for a vast diversity of possible antibody genes, which helps the immune system recognize and respond to a wide range of pathogens.

Question 20

What is the source of activated B cell populations?
A)T cells
B)a population of undifferentiated and indistinguishable progenitor cells
C)a population of differentiated and specific progenitor cells
D)a population of undifferentiated and indistinguishable descendent cells
E)platelets

Accepted Answer

Activated B cell populations arise from a population of undifferentiated and indistinguishable progenitor cells.

Quiz 17: The Immune Response

When an antigen binds to the antibody in the membrane of a B cell, the B cell proliferates and forms a population of B lymphocytes that all make the same antibody. The population of B lymphocytes thus formed is called ________.

What cellular structure is found to be greatly expanded in plasma cells, but not in their precursor cells?

The foreign molecules that stimulate the adaptive immune system to make antibodies are called ________.

Which of the following models for the induction of antibodies was proposed initially by Niels Jerne?

Some activated B cells remain in lymphoid tissue and respond rapidly at a later date if the antigen reappears in the body. Such cells are called __________.

When does the full repertoire of antibody-producing cells (all such cells that a person will ever have) appear in the lymphoid tissue?

Which immune system component is found in plants but NOT vertebrates?

What immune system organ is located in the chest, is responsible for the differentiation of T cells, and reaches its peak size during childhood?

What allows so many different antibodies to be made by the immune system?

Which of the antigens below are typically able to activate B cells without the involvement of T cells?

Sensing of pathogen effector proteins by plant cells can lead to all of the following defensive responses EXCEPT:

Who realized that a cowpox infection at an early age protected people against deadly smallpox infections?

PAMP-triggered immunity in plants can activate over 1,000 genes in Arabidopsis via _________________ -mediated stimulation.

What is usually required for B cell activation by an antigen?

_________ are capable of stimulating immunity but are genetically modified so that they are unable to cause disease.

What events lead to a differentiating B cell becoming committed to producing only one species of antibody molecule?

Some activated B cells differentiate into short-lived cells that secrete large amounts of antibodies. Such cells are called __________.

What happens to plasma cells after the removal of the original antigenic stimulus?

Genes encoding antibodies are generated by a process in which DNA segments are _______ combined.

What is the source of activated B cell populations?