Final BIOL3030
How many antibodies can be produced by a single human B cell?
1 : single B cell can recognize only one antigen
Which of the following best describes the neuroendocrine-to-endocrine pathway of hormone action?
A neural organ that produces hormones regulates another gland through the release of hormones into the circulation that travel to the affected gland
What is the difference between an epitope and an antigen?
An epitope is the part of an antigen where an antibody or lymphocyte receptor binds.
Which statement best describes the difference in response of effector B cells (plasma cells) and cytotoxic T cells?
B cells secrete antibodies against a pathogen, cytotoxic T cells kill pathogens infected host cells
How are cytotoxic T lymphocytes (CTLs) produced?
CD8+ T cells divide and differentiate into cytotoxic T lymphocytes.
Tadpoles must undergo a major metamorphosis to become frogs. This change includes reabsorption of the tail, growth of limbs, calcification of the skeleton, increase in rhodopsin in the eye, development of lungs, change in hemoglobin structure, and reformation of the gut from the long gut of an herbivore to the short gut of a carnivore. Amazingly, all of these changes are induced by triiodothyronine. What is the most likely explanation for such a wide array of effects of thyroxine?
Different tissues have thyroxine receptors that activate different signal transduction pathways.
How do cells involved in the humoral response respond to antigen presentation on the surface of a B cell?
Helper T cells recognize the receptor-antigen complex and cause plasma and memory cells to be produced to then produce antibodies.
Which of the following is NOT an accurate statement?
Hormones of the same chemical class usually have the same function.
Engulfing-phagocytic cells of innate immunity of vertebrates include _____. I) neutrophils II) macrophages III) dendritic cells IV) natural killer cells
I, II, and III
Your sister-in-law never gets sick, while her male neighbor seems to be sick all the time. Although there are several explanations for this, one is that they are genetically different. Which of the following hypotheses concerning genetic inheritance of major histocompatibility complex (MHC) molecules is consistent with this observation and your understanding of the immune system?
In the case of MHC, it is beneficial to have as many different alleles as possible, so heterozygous individuals are healthier than homozygous dominant or recessive individuals.
what is likely to cause the reddening associated with an infection?
Increased blood flow to the area
What is the advantage of assembling the variable region of an antibody from discrete gene segments in a B cell?
It allows for more possible combinations
What major advantage is conveyed by having a system of adaptive immunity?
It enables a rapid defense against an antigen that has been previously encountered.
How do cells involved in the innate immune response detect the presence of pathogens?
Leukocytes recognize unique molecules on pathogens
Which of the following is a difference between B cells and T cells?
One has a major role in antibody production, while the other has a major role in cytotoxicity.
What is the unique characteristic of a steroid hormone that allows it to go through a cellular membrane (i.e., the phospholipid bilayer)?
Steroid hormone is lipid soluble so it can go through the phospholipid bilayer.
How does the immune system of vertebrates utilize a chemical concentration gradient?
The immune system releases chemical signals called chemokines, which create a chemical gradient that leukocytes use in migrating toward the infection site.
Which of the following is an example of a subunit vaccine?
The surface protein of a virus is used to make the vaccine
Why are antigen-presenting cells required for the differentiation of B cells into plasma cells?
They activate CD4+ T cells
best describes the role of mast cells in the inflammatory response
They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream. Mast cells release chemicals that dilate nearby capillaries, increasing their permeability and allowing blood components to enter the region from the bloodstream, thus causing localized swelling
Which of the following is an example of negative feedback?
When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases as blood glucose decreases.
Which of the following is the best definition of autoimmune disease?
a condition in which self molecules are treated as non-self
Fight-or-flight reactions include activation of the _____.
adrenal medulla, leading to increased secretion of epinephrine
During a stressful interval, _____.
adrenocorticotropic hormone (ACTH) stimulates the adrenal cortex, and neurons of the sympathetic nervous system stimulate the adrenal medulla
Clonal selection is an explanation for how _____.
an antigen can provoke production of high levels of specific antibodies
Estradiol is an example of _____.
an estrogen
A patient who has a high level of mast cell activity, dilation of blood vessels, and acute drop in blood pressure is likely suffering from _____.
anaphylactic shock immediately following exposure to an allergen
Clonal selection implies that ____
antigens increase mitosis in specific lymphocytes.
A fruit fly, internally infected by a potentially pathogenic fungus, is protected by
antimicrobial peptides
Most animal hormones
are carried to target cells in the blood or hemolymph
A newborn who is accidentally given a drug that destroys the thymus would most likely
be unable to differentiate and mature T cells
B cells have antigen receptors that bind to antigens that are either freely dissolved or present on the surface of invading or foreign cells. T cells have antigen receptors that _____.
bind to antigen fragments presented on major histocompatability (MHC) complexes by host cells
Mature human sperm and ova are similar in that they
both have the same number of chromosomes
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, at which time she had merely experienced a mild sore throat and swollen lymph nodes in her neck. This time, though infected, she does not get sick. The EBV antigen fragments will be presented by the virus-infected cells along with _____.
class I MHC molecules
In vertebrate animals, spermatogenesis and oogenesis differ in that _____.
cytokinesis is unequal in oogenesis, whereas it is equal in spermatogenesis
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, at which time 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 system's recognition of the second infection involves memory _____.
cytotoxic T cells
Which of the following cells are involved in cell-mediated immunity and also respond to class I MHC molecule-antigen complexes?
cytotoxic T cells
T cells of the immune system include
cytotoxic and helper cells
The number of major histocompatibility (MHC) protein combinations possible in a given population is enormous. However, an individual in that diverse population has a far more limited array of MHC molecules because
each of the MHC genes has a large number of alleles, but each individual only inherits two for each gene
Sperm cells mature and are stored within human males in the
epididymis
Prior to ovulation, the primary steroid hormone secreted by the growing follicle is
estradiol
Prior to ovulation, the primary steroid hormone secreted by the growing follicle is _____.
estradiol
A bone marrow transplant may not be appropriate from a given donor (Jane) to a given recipient (Jane's cousin Bob), even though Jane has previously given blood for one of Bob's needed transfusions, because
even though Jane's blood type is a match to Bob's, her major histocompatibility (MHC) proteins may not be a match
Which of the following is an example of sexual reproduction?
fertilization in Daphnia
In correct chronological order, the three phases of the human ovarian cycle are _____.
follicular → ovulation → luteal
Antigens
foreign molecules that can initiate an immune response
B cells and T cells have variable receptors that allow them to recognize virtually any epitope. What is responsible for this diversity?
gene recombination
The hypothalamic hormone that triggers the secretion of follicle-stimulating hormone (FSH) is _____.
gonadotropin-releasing hormone (GnRH)
A target tissue of a hormone is a tissue that
has receptors for that specific hormone
An inflammation-causing signal released by mast cells at the site of an infection is
histamine
what molecule acts similarly to applying direct pressure to a wound to close blood vessels?
histamines
In excreted urine, a reliable "marker" that a pregnancy has initiated is
human chorionic gonadotropin (hCG)
Hormones secreted by the posterior pituitary gland are made in the
hypothalamus
After drinking alcoholic beverages, increased urine excretion is the result of
inhibited secretion of antidiuretic hormone (ADH)
An example of antagonistic hormones controlling homeostasis is _____.
insulin and glucagon in glucose metabolism
Which of the following is characteristic of a steroid hormone action?
internal receptor binding
Innate immunity _____.
is activated immediately upon infection
If a person loses a large amount of water in a short period of time, he or she may die from dehydration. Antidiuretic hormone (ADH) can help reduce water loss through its interaction with its target cells in the _____.
kidney
Vaccination increases the number of _____.
lymphocytes with receptors that can bind to the pathogen
Which of the following cells can engulf a pathogen?
macrophages
The primary function of the corpus luteum is to _____.
maintain progesterone and estrogen synthesis after ovulation has occurred
A function of antibodies is to _____.
mark pathogenic cells for destruction
leukocytes of innate immune system
mast cells, macrophages, and neutrophils
If a patient is missing B and T cells, what would be absent from the immune response?
memory
In correct chronological order, the three phases of the human ovarian cycle are
menstrual --> proliferative --> secretory
At the end of a non-pregnant ovarian cycle, the breakdown and discharge of the soft uterine tissues is called
mensuration
CD4 and CD8 are
molecules present on the surface of T cells where they interact with MHC molecules.
Engulfing-phagocytic cells of innate immunity include all of the following except
natural killer cells
An immunoglobulin (Ig) molecule, of whatever class, with regions symbolized as C or V, H or L, has a light chain made up of
one C region and one V region
Which of the following are examples of amplification of a hormone signal? I) Epinephrine initiates an enzyme cascade. II) Steroids bind hormone-response elements in the cell and initiate transcription of many genes. III) A quantity of 0.09 mg of growth hormone leads to a 10,000-mg weight gain in a cow. IV) Different cell types have different receptors capable of binding the same hormone.
only I, II, and III
Which of the following would help a virus avoid triggering an effective adaptive immune response? I) having frequent mutations in genes for surface proteins II) building the viral shell from host proteins III) producing proteins very similar to those of other viruses IV) infecting and killing helper T cells
only I, II, and IV
Which of the following statements are fundamental to the clonal selection theory of how the adaptive immune system functions?
only I, II, and IV each lymphocyte has a unique membrane receptor; when the lymphocyte binds and antigen, it is activated and begins dividing; cloned cells descend from an activated lymphocyte and persist even after the pathogen is eliminated
Lymphocytes mature in the _____.I) spleenII) thymusIII) bone marrow
only II and III
The reason that the steroid hormone aldosterone affects only a small number of cells in the body is that _____.
only its target cells contain aldosterone receptors
A pregnant woman comes into the hospital past her due date. The doctor decides it is time for the baby to be delivered. Before performing a cesarean section, the doctor wants to try to induce labor. Which of the following would she most likely inject?
oxytocin
Labor contractions can be increased by the medical use of a synthetic drug that mimics the action of _____.
oxytocin
Which hormone is correctly paired with its action?
oxytocin — stimulates uterine contractions during childbirth
What type of immunity is associated with breast feeding?
passive immunity
Adaptive immunity is based upon _____.
pathogen-specific recognition
What is the only type of chemical signal that does not alter the physiology of the animal producing that signal?
phermones
B cells that have been stimulated by interleukin-2 develop into _____.
plasma cells
what cell produce and secrete antibodies?
plasma cells
what occurs first in immune response when a wound that breaks the skin
platelets release protein that form clots and decrease bleeding.
Which of the following is crucial to activation of the adaptive immune response?
presentation of MHC (major histocompatibility complex)-antigen complex on a cell surface
The primary function of humoral immunity (humoral response) is to
protect the body against extracellular pathogens
A contraceptive pill that continuously inhibits the release of gonadotropin-releasing hormone (GnRH)from the hypothalamus will _____.
reduce the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary gland
The adaptive immune response differs from the innate based upon?
specificity of the response
Which of the following correctly describes a difference between spermatogenesis and oogenesis?
spermatogenesis results in four mature sperm cells, while oogenesis results in one mature egg cell.
A cell that contains proteins enabling a hormone to selectively bind to its plasma membrane is called a(n)
target cell.
Immunological memory accounts for
the ancient observation that someone who had recovered from the plague could safely care for those newly diseased
When antibodies bind antigens, the clumping of antigens results from
the antibody having at least two binding regions
The primary difference between estrous and menstrual cycles is that
the endometrium shed by the uterus during the estrous cycle is reabsorbed with no extensive fluid flow out the body, whereas the shed endometrium of menstrual cycles is excreted from the body
An inactivating mutation in the progesterone receptor gene would likely result in
the inability of the uterus to support pregnancy
Peaks of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) production occur during _____.
the period just before ovulation
Among these contraception methods, the highest risk of accidental pregnancy accompanies _____.
the practice of coitus interruptus
A key part of the humoral immune response is
the production of antibodies by plasma cells
Which of the following should be the same in identical twins?
the set of major histocompatability (MHC) molecules produced
For the successful development of a vaccine to be used against a pathogen, it is necessary that _____.
the surface antigens of the pathogen stay the same
Imagine that a woman is in the final week of her pregnancy. Her doctor gives her an injection of oxytocin. The likely result of this is that the pregnant women would
undergo vigorous contractions of her uterine muscles
Ovulation is the follicular response to a burst of secretion of
uteinizing hormone (LH)
