Biology Exam 6
The human large intestine is about ___ in length
1.5 m
Morbid obesity is defined as having a BMI (body mass index) of at least
fourty
The hormone released from the hypothalamus that stimulates release of LH and FSH in both the male and female is
gonadotropin-releasing hormone
In organisms that reproduce sexually, ___ are the sex cells that carry the genetic information from each parent.
haploid gametes
The "master cells" of the immune system that initiate and coordinate the adaptive immune response are
helper T cells
Animals that eat only plants are
herbivores
The cecum is the largest in
herbivores
The hormone that is the basis of most pregnancy tests is the
human chorionic gonadotropin
The part of the brain that is primarily involved in regulating the body temperature of humans is the
hypothalamus
If a preembryo splits before day 12 of development in humans, then ___ are usually formed
identical twins
Hibernating mammals accumulate large stores of brown fat containing many mitochondria. These mitochondria can burn the fat without generating ATP. What effect would burning fat without regenerating ATP have on the hibernating mammal?
increased body temperature
In sequence of their occurrence, the four major steps that vertebrate organisms use to obtain and use food are
ingestion, digestion, absorption, and elimination
A female chicken laying a fertilized egg has undergone ___ with a rooster
internal fertilization
A mammal
is endothermic and has a body temperature maintained by its own metabolism
Menopause
is the cessation of menstruation
The major excretory organ of the human urinary system is the
kidney
Which of the following produces bile?
liver
B cells or T cells are
lymphocytes
A cell that does not circulate in blood, but instead settles in tissues near the skin and the digestive tract, producing and releasing histamine when tissue is damaged, is a
mast cell
The functional unit of a kidney is a
nephron
Hyponatremia is a low sodium in the blood. This is a concern for marathon runners who drink too much water, and can cause life-threatening pressure on the brain. Why would this occur?
neurons cannot give the kidneys signals to reabsorb sodium ions
The energy needed to raise one kilogram of water from 14.5 degrees centigrade to 15.5 degrees centigrade under controlled conditions is
one kilocalorie
The cells in the ovary that give rise to the mature egg cells are the
oocytes
A disease-causing agent that does not usually infect and cause disease in a person with a healthy immune system is termed a(n)
opportunistic pathogen
Which f the following is not considered to be a major part of the immune system?
pancreas
In the section "Investigating Life: The Hidden Cost of Hygiene", what is the hygiene hypothesis?
people who have fewer infections will have an overactive immune system
The enzyme that breaks down protein is
pepsin
Rhythmic smooth muscle contractions occurring along the human digestive system that propel food along the system are termed
peristalsis
Thalidomide was given to pregnant women from 1957-1961 to help relieve the symptoms of morning sickness. Thalidomide binds to and inactivates the protein cereblon, which is important in limb formation. If a woman took thalidomide during the ___ period of her baby's development, it could result in stunted growth of their limbs
preembryonic
In the male the sac-like structure that contains the testes is the
scrotum
Which of the following is caused by a vitamin C deficiency?
scurvy
A gene called the ___ must be activated at week seven of embryonic development for male sex organs and glands to develop
sex-determining gene on the Y chromosome
How does a vasectomy cause sterility?
sperm cannot move to the urethra
The only animals that rely solely on intracellular digestion are
sponges
Which of the following begins to be digested by saliva?
starch (not an option listed but this is literally what it digests)
Acid reflux would occur under which of the following conditions?
stomach contents leak into the esophagus
In the late 1950s, some women took ___ as a tranquilizer to relieve morning sickness and it caused deformed limbs in developing embryos
thalidomide
Cilia sweep the released mature oocytes from ovaries into the
uterine tubes
Why is there potential for a woman's body to recognize her fetus as foreign?
the fetus and the mother are not genetically identical
The surge of the hormone ___ in the bloodstream of the female triggers ovulation
LH
Athletes who take synthetic steroids can become sterile due to lack of sperm production. This is because of negative feedback on which of the following?
the testes
A patient can have antibodies against many strains of HIV. Which of the following is the main reason that an effective vaccine has not been produced for the HIV virus that causes AIDS?
the virus mutates rapidly, changing its outer coat
The control of an organism's body temperature is
thermoregulation
Which of the following statements about sexually-transmitted diseases is wrong?
STDs are unique to humans
Epithelial cells of the small intestine can have about 500 microvilli on them. What is the purpose of these microvilli?
to increase surface area for food absorption
Which of the following are examples of passive immunity?
a fetus acquiring antibodies through the placenta, or a person receiving an injection of antibodies
Rh incompatibility is due to an immune reaction to which of the following by a pregnant woman?
a foreign antigen on red blood cells
What does the human reproductive system create?
a genetically-unique offspring
The steroid hormone produced by the adrenal cortex that raises blood pressure is
aldosterone
The innate chemical defense substance that activates T cells and B cells is
all of the answers (histamine, complement protein, interleukin, epinephrine)
In humans, the transparent sac that contains fluid that cushions the embryo and maintains a constant temperature and pressure is the
amnion
The enzyme that breaks down starch is
amylase
In human males, the different types of male sex hormones are collectively called
androgens
In many autoimmune diseases such as lupus and rheumatoid arthritis, antibody complexes form in the blood. Kidney failure is a common consequence of these diseases for which reason?
antibodies attack the kidney
A molecule that stimulates an immune-system reaction by B cells and T cells is termed a(n)
antigen
Mature human sperm cells
are haploid
Many parasites are too large to be engulfed by phagocytosis. Which of the following would be effective in killing parasites?
basophils
Every year the common flu vaccine is designed to protect against three different strains of the influenza virus. Why do scientists typically have to make a new vaccine every year?
because the virus develops resistance to the vaccine
If a person has their gall bladder removed, they are typically put on a low-fat diet. Which of the following would explain this recommendation?
bile acids cannot be produced
Like the kidney, a dialysis machine filters all but which of the following out of the blood?
blood cells
Immunological memory results from the production of
both B and T memory cells
In herbivores, cellulose is primarily broken down
by bacteria living within the herbivore's gastrointestinal tract
Which of the following would occur if the lymphatic system was absent?
cancer cells located in the body would not be destroyed if they were not in the blood
Animals that hunt and eat essentially only other animals are
carnivores
In animals, the pouch that forms the entrance to the large intestine is the
cecum
A phagocyte is a
cell that engulfs other cells and debris
Often a woman may first suspect she is pregnant when she misses a period or menstrual cycle. What causes a pregnant woman to miss a period?
chorionic gonadotropin causes the corpus luteum to produce progesterone
The semisolid mass of food and gastric juice in the human stomach is termed
chyme
Which of the following is NOT a component of a sperm cell?
cilia
In a process called ___, an army of plasma cells and memory cells are produced from properly-stimulated B cells
clonal selection
The substance that when activated triggers a chain reaction that punctures bacterial cell membranes is
complement protein
The primary function of a vaccine is to
create immunological memory without causing disease
Which of the following is NOT attacked by the immune system as an intruder in humans?
dead skin cells
Diuretics are commonly prescribed drugs for patients with hypertension because they
decrease blood volume and blood pressure
What effect would drinking salt water have in a human?
dehydration as the extra salt pulls water out of the blood into the urine
Animals that consume decaying organic matter as their main source of food are
detritivores
In the section "Investigating Life: The Hidden Cost of Hygiene", flatworms are very thin and lack a specialized respiratory or circulatory system. How does oxygen reach their cells?
diffusion through the wall of their body
A baby turtle growing into an adult that appears similar is an example of
direct development
An organism that alters its behavior to manage the gain of heat from or loss of heat to the environment is termed a(n)
ectotherm
Which of the following is an advantage of ectothermy over endothermy?
ectotherms require less food and energy
The structure that secretes most of the fluid found in the semen and opens into the vas deferens is the
ejaculatory duct
The stage of human development that occurs from implantation to about eight weeks after fertilization is the
embryonic stage
An organism that manages its temperature by its own metabolism is termed a(n)
endotherm
Which of the following is an advantage of endothermy over ectothermy?
endotherms can move quickly even if it is cold
Antacids would be effective in which part of the digestive system?
esophagus
Fertilization of a secondary oocyte normally occurs in the
fallopian tube
Male gametes unite with the female gametes in organisms that reproduce sexually during
fertilization
In a secondary oocyte, meiosis is arrested in metaphase II until
fertilization occurs
The chemical composition of urine reflects the process of
filtration, absorption, and secretion
When the concentration of solute in the cell is higher than the environment,
water moves into the cell by osmosis
The diploid first cell of a new organism is a(n)
zygote
The correct sequence for the stages in development from conception to birth is
zygote, preembryonic stage, embryonic stage, fetal stage
The major artery that delivers blood to the kidney is the
renal artery
Which of the following diseases is caused by a deficiency of vitamin D?
rickets
Kidney stones are calcium-rich crystals that form inside the kidney and can be triggered by dehydration for which reason?
salt concentrations increase as blood volume drops
Why would HIV infection lead to immunodeficiency?
HIV infects helper T cells
The hormone released by the anterior pituitary that stimulates the development of the corpeus luteum is
LH
The tightly coiled structure (structures) inside the testes that produce the sperm cells is (are) the
seminiferous tubules
The main site of food absorption in the human digestive system is the
small intestine
If a human fetus is ___ and the pregnant woman is ___, an incompatibility that destroys the red blood cells of the fetus may occur.
Rh-negative; Rh-positive
Rings of muscle in the digestive tract that can open and close, regulating the movement of food into or out of parts of the digestive system, are
sphincters
Why do lymph nodes often become swollen during an infection?
T cells reproduce in lymph nodes after being exposed to pathogens
Which of the following vaccines would expose a person to an antigen for the longest time, and thus be the least likely to require repeated booster vaccinations?
subunits of pathogens
Homeostasis is defined as
the ability of an organism to maintain a stable internal environment
In the section "Investigating Life: The Hidden Cost of Hygiene", which of the following occurred during the coevolution of humans and pathogens that causes disease?
the pathogens produce substances that suppress our immune system
How does the immune system recognize pathogens it has fought before?
the primary immune response creates memory B and memory T cells which are activated in a secondary immune response
Why would AIDS patients infected with HIV be at risk for opportunistic infections and rare cancers?
their immune systems are suppressed
Athletes who take synthetic steroids can become sterile due to lack of sperm production. This is because the synthetic steroids cause which of the following?
a decrease in FSH and LH production
A diuretic is
a substance that increases the volume of urine
Although impossible in humans, what is the result if two sperm fertilized an egg?
a triploid zygote with all of the chromosomes from each gamete
Each year there are an estimated 250,000 people who could benefit from a bone marrow transplant. What would happen to a patient who no longer had active bone marrow?
they would be immunocompromised
The cap-like ___ covers the head of the sperm and releases enzymes that will help the sperm penetrate the egg
acrosome
Cells often use ___ to move ions against their concentration gradients
active transport
Which of the following is a major difference between adaptive immunity and innate defenses?
adaptive immunity responses are produced only on demand; innate defenses are always produced
Which of the following correctly describes B cells and T cells?
all answers are correct (B cells and T cells are lymphocytes, attack cancerous cells in the body, attack foreign particles in the body, are not innate defenses)
The homeostasis of water in organisms is affected by
all answers are correct (blood composition, nutrition, sweating when internal temperatures are too hot, salt concentrations)
Which of the following is a reason why fever is considered a defense mechanism?
all answers are correct (fever inactivates (kills) some viruses, fever speeds up the rate of phagocytosis, fever reduces the iron level in the blood, thereby retarding the growth of some bacteria, fever kills some bacteria)
How can an individual protect himself/herself against sexually transmitted diseases?
all answers are correct (get tested regularly and treat all STDs, remain in a monogamous relationship with another individual who has been recently tested for STDs, abstain from sexual activity or use a latex condom during sexual activity, get vaccinated against HPV and hepatitis B)
A nutrient is a substance that an organism uses for
all answers are correct (growth, metabolism, maintenance, repair of tissues)
Which of the following is correct about primary and secondary immune responses?
all answers are correct (primary immune response occurs first and is smaller, both respond to foreign antigens and are responses of adaptive immunity)
Which of the following is a method in which a pathogen can enter a vertebrate and the immune system defends against it?
all answers are correct (sneezing, viruses, parasites, kissing)
In the human male and female reproductive systems, each system contains paired primary sex organs called ___, which contain ___ that give rise to gametes
all answers are correct (testes and sperm cells, gonads and germ cells, ovaries and egg cells, germ cells and hormones)
Physical and chemical barriers that form the first line of innate defense include
all answers are correct (the acidity of the stomach, tear fluid from the eye, an un-punctured skin, mucus and cilia of the respiratory tract)
Why must organisms eat?
all answers are correct (to obtain potential energy stored in the chemical bonds, to provide reactants for respiration to make ATP, to obtain the monomers of proteins, lipids, and carbohydrates constructed in organisms, to obtain carbohydrates, proteins and lipids)
Why does the expulsion of the placenta not occur until the final stage of labor?
all answers are correct (to remove waste from the fetus during labor, to provide nourishment to the fetus during labor, to provide oxygen to the fetus during labor, to remove carbon dioxide from the fetus during labor)
An exaggerated attack on a harmless antigen by an overly-sensitive immune system is termed a(n)
allergy
Which of the following are examples of humoral immunity?
antibodies produced that clone a pathogen
A Y-shaped protein that is produced in response to a specific antigen and recognizes these antigens is a(n)
antibody
Which of the following is not part of the innate defense response?
antibody production
In the section "Investigating Life: The Hidden Cost of Hygiene", which of the following would a person in a less-developed country be less likely to have than a person in a more-developed country, according to the hygiene hypothesis?
asthma
If a tumor metastasizes, this means that it has moved to another part of the body. Doctors often look in lymph nodes near a tumor for signs of metastasis. Why might cancer cells be found in lymph nodes?
because white blood cells are formed in lymph nodes in response to the tumor
Which of the following are endothermic?
both birds and mammals
Humans may conserve or generate heat in cold weather by
both blood vessels near the surface of the skin constricting and shivering
Humans may decrease their body temperature in hot weather by
both blood vessels near the surface of the skin dilating and sweating
Histamine triggers vasodilation and leakiness in blood vessels during inflammation. Why would this be beneficial in fighting an infection by a pathogen?
both increased number of white blood cells and their migration to site of infection
If a person eats large quantities of food and then intentionally vomits, constantly going through what are called binge and purge patterns, they most likely suffer from the eating disorder known as
bulimia
In females, nearly all cases of ___ cancer are associated with the human papillomavirus
cervical
The end of the uterus that opens to the vagina is the
cervix
A primary source of vitamin C in our diets is
citrus fruit
The 2 cm-long structure in the human female that stimulates her to experience orgasm is the
clitoris
Every year the common flu vaccine is designed to protect against three different strains of the influenza virus. How is your body able to raise antibodies against so many new forms of the flu virus?
clonal deletion of B and T cells that recognize the virus occurs
The gland that forms from ruptured follicle cells in the ovary and secretes estrogen and progesterone is the
corpeus luteum
Unlike humans, cows emit up to 200 L of methane (CH4) each day through belching. Which of the following explains this difference?
cows have a rumen
Special cells produced by the immune system that are progeny of properly-stimulated B cells and are antibody-producing factories are
cytotoxic T cells
Antibodies are made against a very small portion of an antigen called an epitope. An epitope is often just 5-6 amino acids from a protein on an antigen. Which of the following explains how antibodies could be produced against just a small part of an antigen?
cytotoxic T cells poke holes in the antigen
What is the ideal outcome of the human reproductive system?
to create individuals better suited to the environment than the existing individuals
The function of bile is to
emulsify fats
The tightly coiled tube that receives and stores sperm from one testis is a(n)
epidydimus
The structure that covers the opening to the trachea during swallowing, thereby preventing food from entering the air passage, is the
epiglottis
The muscular tube leading from the pharynx to the stomach is the
esophagus
A female salmon laying unfertilized eggs in a nest is preparing them for ___ by a male salmon
external fertilization
Which is a disadvantage of intracellular digestion that does not affect extracellular digestion?
food must be smaller than a cell
Ammonia is toxic and must be secreted as a dilute solution. Why do most freshwater fish secrete ammonia, but mammals do not?
freshwater fish do not have enough energy to convert ammonia to urea
White blood cells are produced
from bone marrow stem cells
Although the lymphatic system has many similarities to the circulatory system, what can the lymphatic system accomplish which the circulatory system cannot?
generate white blood cells
The innate chemical substance produced by basophils that causes blood vessels to dilate is
histamine
Which of the following organisms is incorrectly matched with its digestive tract?
humans have incomplete digestive tracts
Each year there are an estimated 250,000 people who could benefit from a bone marrow transplant. A major challenge is finding a donor with the matching complex of Major Histocompatibility (MHC) proteins a person needs. Why is it important that the MHC proteins match between the donor and recipient?
if they don't match, the donor's immune system will see the recipient's bone marrow as foreign
A caterpillar turning into a butterfly is an example of
indirect development
Often a woman may first suspect she is pregnant when she misses a period or menstrual cycle. Why is it important for the menstrual cycle to be blocked during a pregnancy?
to prevent additional fertilizations
Why does the surface of the oocyte change when the first sperm cell touches the secondary oocyte?
to prevent more than one sperm from entering the egg
Which of the following descriptions is correctly matched with its term?
innate defenses : able to defend against any pathogen
The innate chemical substance that alerts other cells and components of the immune system to a viral infection is
interferon
A reptile
is ectothermic and has a body temperature that fluctuates as the animal derives its heat from the environment
Alcohol reduces ADH secretion which in turn does which of the following?
it decreases tubule permeability to water and thus increases urine volume
The presence of antibodies against HIV can be used to diagnose an infection that has occurred at least three months earlier. Why couldn't the presence of antibodies against HIV be used to diagnose a more recent infection?
it takes 2-3 months to raise antibodies against the virus
A diaphragm is a shallow, dome-shaped rubber disk with a flexible rim that fits within the vagina and covers the cervix. How does this act as a contraceptive to prevent pregnancy?
it would act as spermicide, killing sperm
How does a birth control pill containing estrogen and progesterone prevent pregnancy>
it would prevent ovulation
Fresh water is much more dilute than the cells of a fish, so the animal constantly takes in water at its gills. How would a freshwater fish osmoregulate?
it would produce dilute urine and use active transport at the gills to get rid of excess salt from the water
Birth control pills contain a combination of estrogen and progesterone. What effect would this have on the anterior pituitary?
it would secrete more FSH and LH
Birth control pills contain a combination of estrogen and progesterone. What effect would this have on the hypothalamus?
it would secrete more gonadotrophin-releasing hormone
The enzyme that breaks down the main sugar found in milk is
lactase
The main site of water and mineral absorption in the human digestive system is the
large intestine
The enzyme that breaks down fats is
lipase
Most multivitamins should be taken with a meal for which reason?
to provide the energy needed to use the vitamins
The role of B cells in adaptive immunity is ___, versus the role of T cells in adaptive immunity is ___.
to secrete antibodies in humoral immunity; to attack bad cells in cell-mediated immunity
The structure that connects the embryo to the placenta is the
umbilical cord
Mammals excrete nitrogen wastes in which of the following?
urea
In humans, the muscular tube into which urine from the kidney first drains is the
ureter
The tube that connects the urinary bladder to the outside of the human body is the
urethra
The muscular sac-like organ of the human female in which the fetus develops is the
uterus
A preparation that "teaches" the immune system to recognize a disease-causing agent without actually causing disease is termed a(n)
vaccination
The tube-like structure that serves as the birth canal in the female is the
vagina
The region of an antibody molecule that recognizes and binds to an antigen is the
variable region
In the male, the tube that extends from the scrotum to the point of connection with the urethra is the
vas deferens
Tiny finger-like projections along the small intestine that are used to absorb nutrients are
villi
Which of the following is correct about sexually-transmitted diseases?
viruses, bacteria, protists, and fungi can cause STDs.
When the concentration of solutes in fluid is higher outside the cell than inside,
water moves out of the cell by osmosis
A primary "antigen presenting cell," a cell that presents an antigen to a helper T cell, is a
macrophage
Which of the following is not considered to be a primary organ in the human digestive system?
mouth
The hormone secreted by the posterior pituitary that causes the reabsorption of more water by the kidney is
ADH
Animals that eat a broad variety of foods, including plants and animals, are
omnivores
Which of the following are examples of active immunity?
only antibodies produced from a vaccine
A tubal ligation is a surgical procedure in which the fallopian tubes are severed, and then tied. How would this cause sterility?
oocytes cannot move to the uterus
If a woman does not know she is pregnant and undergoes a diagnostic medical procedure involving exposure of her abdomen to radiation, then the developing baby may be at risk. Why would the risk of birth defects be highest if the woman received the radiation during weeks 2-8 of her pregnancy?
organs first begin to develop during the embryonic stage
The process used to control the level of water and ions in body fluids is termed
osmoregulation
The diffusion of water across a membrane that is permeable to water but not to ions and other charged solutes is
osmosis
Which of the following diseases is caused by a deficiency of niacin?
pellagra
The stage of human development in which the endoderm, mesoderm, and the ectoderm form is the
preembryonic stage (not an option?)
Ocean water is much saltier than a fish's cells, so the animal loses water by osmosis, mostly at the gills. How would a saltwater fish osmoregulate?
produce dilute urine and use active transport at the gills to get rid of excess salts
The structure that secretes a thin, milky, alkaline fluid that activates the sperm to swim is the
prostate gland
If you transfuse type AB blood into a patient with type A blood, the patient will raise antibodies against the B antigen on the donor's blood, but will not raise antibodies against the A antigen. Why not?
B and T cells that recognize the A antigen will have been removed by clonal deletion
HIV-positive people track the progress of their disease with blood tests that measure the number of
B cells
The structure of reproductive systems is similar between some organisms. What prevents fertilization of gametes from different organisms?
proteins on the surface of the egg and sperm are only recognized by the correct organism
