Test 4

Which statement about heart attacks and strokes is true? Both heart attacks and strokes lead to cell death by cutting off oxygen and nutrient supplies to the affected tissues. The underlying conditions that lead to heart attacks and strokes appear suddenly and without warning. Both heart attacks and strokes result primarily from atherosclerosis in the aorta. Deaths from heart attacks are largely unavoidable. The damage from a stroke or heart attack is temporary and easily repaired by the body.

Both heart attacks and strokes lead to cell death by cutting off oxygen and nutrient supplies to the affected tissues.

The graph depicts hormone levels during a woman's monthly reproductive cycle. At what point on the graph does the secondary oocyte erupt from the follicle and out of the ovary? at point A (about 11 days) at point B (about 14 days) at point C (about 21 days) at point D (about 27 days) The point at which this occurs is not represented by a line on the graph.

at point B (about 14 days)

The development of plaques on the inner walls of arteries, which reduces the flow of blood, is known as: atherosclerosis. arteriosclerosis. hypercholesterolemia. a heart attack. partial pressure.

atherosclerosis.

Fertilization takes place in the reproductive tract of the female individual in which type of organisms? echinoderms frogs birds cnidarians sponges

birds

In the countercurrent exchange system of a fish gill: blood moves through the capillaries in the lamellae while water passes over the lamellae. blood moves through the gill arches while water passes over the gill filaments. blood moves through the lamellae and through the gill filaments. blood moves through the gill filaments and the gill arches. water moves into the fish's mouth while oxygen moves out.

blood moves through the capillaries in the lamellae while water passes over the lamellae.

The left side of the heart pumps blood to the _________ in the _________ circuit. lungs; pulmonary lungs; systemic brain; pulmonary body tissues; systemic body tissues; pulmonary

body tissues; systemic

Both red blood cells and white blood cells are derived from cells in the: spleen. pancreas. bone marrow. gall bladder. liver.

bone marrow.

Which of the following is not a function of the blood plasma in vertebrates? transporting nutrients throughout the body transporting cells involved in immune response to invasion of the body transporting hormones throughout the body buffering the pH of the body breaking down large carbohydrates into more easily absorbable smaller carbohydrates

breaking down large carbohydrates into more easily absorbable smaller carbohydrates

In human lungs, the windpipe branches into two bronchi. The bronchi then branch several times to become: bronchioles. the larynx. alveoli. lungs. the trachea.

bronchioles.

An animal called a hydra can reproduce by growing a miniature version of itself directly from the tissues of the parent. The miniature hydra then breaks off and grows to full size. This type of reproduction is best called: fragmentation. sexual reproduction. parthenogenesis. budding. binary fission.

budding.

One of the main actions of the hormone progesterone is to: stimulate oogenesis to begin. trigger the release of estrogen. cause the endometrium to thicken. initiate follicle development. initiate menstruation.

cause the endometrium to thicken.

The circular muscle at the opening to the uterus in human females is called the: oviduct. clitoris. vagina. cervix. ovary.

cervix.

In the human menstrual cycle, ovulation occurs when an unfertilized egg is released from a follicle in the ovary. The ruptured follicle then develops into a temporary endocrine structure known as the ________, which secretes estrogen and progesterone. Barr body zona pellucida corpus luteum endometrium afterbirth

corpus luteum

Which of the following is most responsible for initiating labor? release of prolactin from the pituitary gland kicking and punching of the baby inside the uterus estrogen and prostaglandin production a baby's cry the expulsion of the placenta, along with lots of watery fluid

estrogen and prostaglandin production

In which stage of embryonic development are the germ layers created? ovulation fertilization cleavage gastrulation neurulation

gastrulation

In animals, the endoderm, mesoderm, and ectoderm are the types of: tissues. body cavities. developmental stages. cells. germ layers.

germ layers.

Compared to maternal hemoglobin, we would expect fetal hemoglobin to: be less saturated with oxygen. give up oxygen more readily. be less "sticky." have a higher affinity for oxygen. contain less iron.

have a higher affinity for oxygen.

Birth control pills and patches are examples of what type of method of contraception and birth control? barrier methods hormonal methods sterilization intrauterine devices "natural" methods

hormonal methods

Which of the following sexually transmitted diseases has a vaccine currently available to prevent it? HIV/AIDS chlamydia human papilloma virus (HPV) crab lice trichomoniasis

human papilloma virus (HPV)

Where is the pacemaker of the heart located? in the right ventricle in the left atrium in the right atrium in the left ventricle in the center of the heart, at the junction between the atria and ventricles

in the right atrium

Which of the following is not a likely characteristic of an organism that relies on simple diffusion for respiration? aquatic a body only a few cells thick low metabolic rate small size low surface area to volume ratio

low surface area to volume ratio

The right side of the heart pumps blood to the _________ in the _________ circuit. lungs; systemic lungs; pulmonary brain; pulmonary body tissues; systemic body tissues; pulmonary

lungs; pulmonary

During the human menstrual cycle, a sudden increase in which of the following hormones causes the follicle to rupture, releasing the egg from the ovary? ACTH progesterone estrogen follicle stimulating hormone luteinizing hormone

luteinizing hormone

Which of the following hormones targets the ovary? estrogen testosterone prostaglandin luteinizing hormone progesterone

luteinizing hormone

The _____________ is the site of gamete production in human females. endometrium birth canal uterus ovary oviduct

ovary

In the menstrual cycle of the human female, the direct response to the increase in the luteinizing hormone is: oogenesis, to produce a primary oocyte from a oogonium. menstruation. ovulation. estrogen secretion by the adrenals. implantation.

ovulation.

The condition called varicose veins refers to swollen veins in the legs. The observable symptom is blood pooling in the veins, causing them to swell. Of the choices below, which one most likely will lead to the formation of varicose veins? hypertension leaking heart valves malfunctioning valves in veins lower than normal heartbeat atherosclerosis

malfunctioning valves in veins

Which of the following describes the three events in sperm production, from just after meiosis to deposition in the female reproductive tract? primary spermatogenesis, secondary spermatogenesis, and tertiary spermatogenesis maturation, storage and transfer, and delivery mitosis, transport, and delivery stage 1, stage 2, and stage 3 mitosis, separation, and transport

maturation, storage and transfer, and delivery

The three embryonic germ layers formed during gastrulation are ectoderm, endoderm, and ______________. placoderm zygoderm mesoderm metaderm blastoderm

mesoderm

The formation of a multicellular organism from a fertilized egg is called development. Development is accomplished through the processes of: mitosis and cytokinesis. meiosis and cytokinesis. meiosis and mitosis. fission and cytokinesis. mitosis and fission.

mitosis and cytokinesis.

The driving force behind the movement of gas in and out of the blood is: partial pressure of the gas. active diffusion. active transport. the binding affinity of hemoglobin. the amount of hemoglobin.

partial pressure of the gas.

Which condition would most likely lead to a heart attack? high levels of circulating HDL hypotension hematocrit reading below 45% atherosclerosis in the coronary arteries plaque formation in the aorta

plaque formation in the aorta

Which structure plays a role in producing semen? penis vas deferens urethra prostate gland bladder

prostate gland

The "neck" of the sperm: carries the genetic "payload" of the sperm. provides energy for movement. carries the enzymes that help digest the exterior coat of the egg. helps to trigger the completion of meiosis by the sperm cell. prevents more than one sperm from fertilizing the same egg.

provides energy for movement.

Which of the following is responsible for transporting oxygen in the bloodstream? white blood cells red blood cells platelets blood plasma myoglobin

red blood cells

Electrical signals from the sinoatrial node begin in the ________ and quickly spread to the _________, causing both of these chambers to contract synchronously. right atrium; left atrium right atrium; right ventricle left atrium; right atrium left atrium; left ventricle right ventricle; left ventricle

right atrium; left atrium

Blood in the right atrium of the human heart will be pumped into the _____________ and then into the ___________. right ventricle; aorta right ventricle; pulmonary vein right ventricle; pulmonary artery left atrium; aorta left atrium; pulmonary vein

right ventricle; pulmonary artery

Which type of reproduction is most advantageous when the environment is ever changing? budding sexual reproduction parthenogenesis fragmentation binary fission

sexual reproduction

The rhythmic contractions of the heart are initiated by electrical impulses in the: sinoatrial node. electrocardiogram. atrioventricular node. left atrium. semilunar valve.

sinoatrial node.

Which of the following types of tissues is derived from the mesoderm germ layer in embryogenesis? lung tissue pancreatic tissue skeletal muscle liver tissue neuronal tissue

skeletal muscle

In the _________ circuit, blood is pumped from the left ventricle to the ___________. systemic; body tissues systemic; lungs pulmonary; body tissues pulmonary; lungs pulmonary; brain

systemic; body tissues

Where is fertilization most likely to occur? the uterus the cervix the ovaries the vagina the Fallopian tubes

the Fallopian tubes

Which of the following is often coupled with the use of a diaphragm or cervical cap? sterilization abstinence use of spermicidal creams IUDs "morning after" pill

use of spermicidal creams

The ____________ is the site of pregnancy in the human female. uterus bladder ovary oviduct cervix

uterus

Which blood vessels are the first branch of the circulatory system to carry nutrient-poor, carbon dioxide-rich, and waste-rich blood from the body cells back toward the heart? capillaries arteries arterioles veins lymphatic vessels

veins

After exchange with the body tissues is complete, blood is carried back to the heart in the: capillaries. arteries. hemolymph. veins. interstitial fluid.

veins.

If a mother chooses to breastfeed her baby exclusively at least four times a day (spread evenly) in the first several months after birth, she: will produce more colostrum than breast milk. will get "morning sickness," or nausea. will experience a dilation of her cervix within a month's time. will likely not become pregnant again during this period. will experience false labor pains at least four times per day.

will likely not become pregnant again during this period.

When you step outside on a cold day, how does your circulatory system react to keep your body temperature within a normal range? It reduces bloodflow to the skin to minimize heat loss. It expands blood vessels to deliver more warm blood to the skin. It increases the production and transport of immune cells that stimulate fevers. It pumps blood more rapidly to the body surface. It reduces bloodflow to the muscles to prevent heat loss.

It reduces bloodflow to the skin to minimize heat loss.

Which statement is accurate? It takes a smaller change in the partial pressure of oxygen for hemoglobin to go from 100% saturated to 75% saturated than to go from 75% saturated to 50% saturated. After hemoglobin gives up one oxygen molecule, it more readily gives up additional oxygen molecules with smaller changes in partial pressure. Hemoglobin releases two or three oxygen molecules to the tissues during normal metabolism. At any given point in time, all hemoglobin molecules in the body will show the same level of oxygen saturation. Hemoglobin always carries at least one molecule of oxygen.

After hemoglobin gives up one oxygen molecule, it more readily gives up additional oxygen molecules with smaller changes in partial pressure.

Which statement is true concerning assisted reproductive technology methods? All ART procedures have in common that oocytes are collected from the woman's ovaries. IVF-ET differs from GIFT and ZIFT in that one-cell stage fertilized eggs are inserted in the uterus. ZIFT differs from GIFT and IVF-ET in that eight-cell stage fertilized eggs are inserted in the uterus. GIFT differs from ZIFT and IVF-ET in that fertilization occurs in a petri dish. IVF-ET differs from GIFT and ZIFT in that one-cell stage fertilized eggs are inserted in the Fallopian tubes.

All ART procedures have in common that oocytes are collected from the woman's ovaries.

Which statement about blood vessels is true? Arteries carry blood away from the heart. All veins transport oxygen-poor blood. Capillaries have valves to prevent backflow. Veins have sphincters to control the flow of blood to capillary beds. Arteriole networks have a greater total volume than that of all the other blood vessels.

Arteries carry blood away from the heart.

Which statement about the crocodilian circulatory system is true? The heart has two partially divided ventricles. The heart has a single atrium. There is only one circuit of flow. Blood can bypass the lungs and instead flow directly back to the body. Crocodiles have open circulatory systems.

Blood can bypass the lungs and instead flow directly back to the body.

Why do cells require oxygen gas? Cells need to inhale and exhale. Cells need oxygen to make glucose. Cells need oxygen in order to get rid of nitrogenous wastes Cells need oxygen in order to convert sugar into ATP energy. Cells need oxygen in order to have something to trade for carbon dioxide.

Cells need oxygen in order to convert sugar into ATP energy.

What is a major difference between sperm and eggs? Eggs are smaller than sperm. Eggs are produced in much larger numbers than sperm. Egg development begins later in the maturation process than sperm development. Eggs are produced in much smaller numbers than sperm. Egg development takes a shorter amount of time than sperm development.

Eggs are produced in much smaller numbers than sperm.

Which month had the greatest amount of variation between a woman's first day of menstruation and those of her 5-10 closest friends in the dorm? January February/March April October November/December

February/March

Which statement is true concerning assisted reproductive technology methods? GIFT differs from ZIFT and IVF-ET in that oocytes are collected from the woman's ovaries. IVF-ET differs from GIFT and ZIFT in that one-cell stage fertilized eggs are inserted in the uterus. ZIFT differs from GIFT and IVF-ET in that eight-cell stage fertilized eggs are inserted in the uterus. GIFT differs from ZIFT and IVF-ET in that fertilization occurs in the Fallopian tubes. IVF-ET differs from GIFT and ZIFT in that one-cell stage fertilized eggs are inserted in the Fallopian tubes.

IVF-ET differs from GIFT and ZIFT in that one-cell stage fertilized eggs are inserted in the uterus.

Which of the following is a potential disadvantage of asexual reproduction? It eliminates the need to find a mate. It allows perpetuation of a population even when the members are isolated. It allows organisms to multiply quickly. It leads to populations that are genetically the same. It requires more energy to reproduce asexually, compared to sexual reproduction.

It leads to populations that are genetically the same.

How does the increased production of diphosphoglyceric acid (DPG) from training at high altitudes affect hemoglobin? It lowers the oxygen-binding affinity of hemoglobin, making it more likely to give up oxygen at any elevation. It raises the oxygen-binding affinity of hemoglobin, making it more likely to give up oxygen at any elevation. It lowers the oxygen-binding affinity of hemoglobin, making it less likely to give up oxygen at any elevation. It raises the oxygen-binding affinity of hemoglobin, making it less likely to give up oxygen at any elevation. It raises the oxygen-binding affinity of hemoglobin, but does not affect the ability of hemoglobin to give up oxygen.

It lowers the oxygen-binding affinity of hemoglobin, making it more likely to give up oxygen at any elevation.

While studying the mating system of an insect species, you observe that females mate frequently with numerous, different males (polyandry). By contrast, a closely related insect species exhibits a monogamous mating system. What would you expect to be true about the level of sperm competition in the polyandrous species compared to its monogamous relative? Males of the polyandrous species produce less sperm than males of the monogamous species. Males of the polyandrous species lack a toxic, sperm-incapacitating chemical in their semen that is present in males of the monogamous species. Males of the polyandrous species do not produce a mating plug like males of the monogamous species. Males of the polyandrous species make more sperm than males of the monogamous species. Males of the polyandrous species have smaller testicles than the males of the monogamous species.

Males of the polyandrous species do not produce a mating plug like males of the monogamous species.

Which statement about gametogenesis in males is true? Spermatogonium cells undergo mitosis to become sperm cells. Sperm mature in the prostate. Males produce sperm every day. At puberty, males produce all of the sperm that they will have in their lifetime over a 9-10 week period. The epididymis is the site of sperm production.

Males produce sperm every day.

What distinguishes the first trimester from the second and third trimesters? Significant muscle and bone growth occurs in the first trimester. Relatively little growth occurs in the first trimester. Relatively high amounts of new development occur in the second and third trimester. Relatively little growth occurs in the second and third trimester. Significant development of the nervous system occurs in the first trimester.

Relatively little growth occurs in the first trimester.

What are the two stages of gas exchange in large, multicellular organisms? Oxygen moves from the lungs to the bloodstream, and carbon dioxide moves from the bloodstream to the lungs. Oxygen moves from the bloodstream to the body cells, and carbon dioxide moves from the body cells to the bloodstream. Respiratory gases enter the bloodstream from the external environment, and respiratory gases bind to hemoglobin for transport. Respiratory gases move into the lungs from the air, and respiratory gases move out of the lungs into the air. Respiratory gases are exchanged between the external environment and circulatory system, and respiratory gases are exchanged between the circulatory system and body cells.

Respiratory gases are exchanged between the external environment and circulatory system, and respiratory gases are exchanged between the circulatory system and body cells.

Which of the following properly provides the order of function in the human female ovarian cycle? Shedding of the uterine lining causes reduced levels of estrogen, triggering release of FSH; FSH stimulates the growth of an ovarian follicle; the maturing follicle secretes estrogen; FSH and LH surge; ovulation occurs. Shedding of the uterine lining causes increased levels of LH; LH stimulates the growth of an ovarian follicle; the maturing follicle secretes progesterone; FSH and LH surge; ovulation occurs. Shedding of the uterine lining causes reduced levels of estrogen, triggering release of FSH; FSH stimulates the growth of an ovarian follicle; ovulation occurs; the maturing follicle secretes estrogen; FSH and LH surge. Ovulation occurs, triggering menstruation; shedding of the uterine lining causes increased levels of FSH; FSH and LH surge; LH stimulates the growth of an ovarian follicle; the maturing follicle secretes estrogen. Shedding of the uterine lining causes reduced levels of estrogen, triggering release of FSH; FSH stimulates the growth of an ovarian follicle; FSH and LH surge; the maturing follicle secretes estrogen; ovulation occurs.

Shedding of the uterine lining causes reduced levels of estrogen, triggering release of FSH; FSH stimulates the growth of an ovarian follicle; the maturing follicle secretes estrogen; FSH and LH surge; ovulation occurs.

Which statement about reproductive-related technology is true? Sperm-sorting techniques allow parents to select the gender of their child with 100% reliability. Eggs can be "tricked" into developing into normal females if they are pricked with a tiny pin just after ovulation. Sperm can be sorted in the laboratory into those containing an X or a Y. Men who have embryos implanted in their peritoneal cavity can be made pregnant; childbirth requires the cesarean surgical procedure. Embryos can be grown in vitro until the third week of development.

Sperm can be sorted in the laboratory into those containing an X or a Y.

Which statement about male fertility is true? Males produce all of the sperm they will have in their lifetime at the onset of puberty. Sperm must be kept at exactly body temperature to survive. Men who spend too much time in hot tubs will become permanently infertile. Sperm production is particularly sensitive to temperature and hormones. Men produce a maximum of 300 million sperm cells in a lifetime.

Sperm production is particularly sensitive to temperature and hormones.

What changes in menstrual synchrony would you expect to see during the summer months when the women are not living together? The average number of days between the start of menstruation would likely decrease steadily during the summer. The average number of days between the start of menstruation would likely increase steadily during the summer. The average number of days between the start of menstruation would likely return to October levels and remain there throughout the summer. The average number of days between the start of menstruation would likely remain at April levels throughout the summer. The average number of days between the start of menstruation would likely decrease to 0 immediately and remain there throughout the summer.

The average number of days between the start of menstruation would likely increase steadily during the summer.

Which statement below accurately describes a benefit and a cost of "blood doping"? The benefit of blood doping is that hemoglobin becomes more likely to give up oxygen to respiring tissues, whereas the cost is that it is more difficult to extract oxygen from the air. The benefit of blood doping is that the blood becomes thicker, whereas the cost is that the heart must pump harder to circulate it. The benefit of blood doping is an increased number of red blood cells, whereas the cost is a decreased number of white blood cells and platelets. The benefit of blood doping is the increased oxygen-carrying capacity of the blood, whereas the cost is increased viscosity of the blood. The benefit of blood doping is faster transport of blood through the circulatory system, whereas the cost is higher stress on the heart muscles.

The benefit of blood doping is the increased oxygen-carrying capacity of the blood, whereas the cost is increased viscosity of the blood.

Llamas live at high altitudes where the partial pressure of oxygen is much lower. How would the llama oxygen-binding curve for hemoglobin differ from the graph shown? The curve would be shifted to the left because llama hemoglobin has a higher affinity for oxygen. The curve would be shifted to the left because llama hemoglobin has a lower affinity for oxygen. The curve would be shifted to the right because llama hemoglobin has a higher affinity for oxygen. The curve would be shifted to the right because llama hemoglobin has a lower affinity for oxygen. The curve would be shifted upward because llamas live at higher altitudes.

The curve would be shifted to the left because llama hemoglobin has a higher affinity for oxygen.

Which of the following occurs during exhalation? The diaphragm relaxes. The intercostal muscles contract. The volume of the chest cavity increases. The volume of the lungs increases. The rib cage expands.

The diaphragm relaxes.

For which of the following reasons might a man claim a reasonable legal right to an embryo produced by fertilizing an egg with his sperm? The man loved the woman who produced the egg. The man was a good friend of the woman who produced the egg. The woman felt the man should have the embryo. The embryo contains half of the man's DNA. The unborn child has a right to be owned by his biological father.

The embryo contains half of the man's DNA.

What do nearly all mammals have in common during embryonic development? The embryo gets nutrients from the yolk. The embryo develops outside of the female's body. The zygote is formed through external fertilization. The embryo develops inside the female until a live birth occurs. The embryo develops in an egg inside the female's body until hatching.

The embryo develops inside the female until a live birth occurs.

Which of the following is not an aspect of a fish's circulatory system? Blood movement through the gills is the slowest because this is where gas exchange occurs. The heart pumps blood through the body first then past the gills. The blood only flows through the heart once per circuit. A fish's heart has two chambers: one atrium (blood in) and one ventricle (blood out). A fish has a single circuit of flow.

The heart pumps blood through the body first then past the gills.

Research has shown that deer mice populations living at high altitudes have a different variant of hemoglobin than deer mice populations living at low altitudes. What prediction can you make about the hemoglobin in the high-altitude population? The hemoglobin in the high-altitude population will have a higher oxygen binding affinity than that of the low-altitude population. The hemoglobin in the high-altitude population will have a lower oxygen binding affinity than that of the low-altitude population. The oxygen binding affinity of the hemoglobin within the two populations will be the same because they are all members of the same species. The high-altitude population hemoglobin is less likely to release oxygen to respiring muscles than the hemoglobin of the low-altitude population. The hemoglobin in the high-altitude population will only require three oxygen molecules rather than four to be fully saturated.

The hemoglobin in the high-altitude population will have a higher oxygen binding affinity than that of the low-altitude population.

What makes bird respiratory systems so efficient? There is an almost continuous and unidirectional flow of oxygen-rich air through the lungs of birds. The anterior and posterior air sacs significantly increase the surface area for gas exchange between the air and blood. Oxygen-poor air in the posterior air sacs is kept separate from the oxygen-rich air in the anterior air sacs. Each parcel of air is pumped back and forth through the lungs several times in order to extract the maximum amount of oxygen. Birds can inhale and exhale simultaneously through their trachea.

There is an almost continuous and unidirectional flow of oxygen-rich air through the lungs of birds.

At 15,000 feet above sea level, the air pressure is half of what it is at sea level. What is the best explanation for this phenomenon? It is much colder at higher elevations, and colder environments hold fewer air molecules. There is less atmosphere above the air pushing down on it. Air tends to drift away at higher elevations because gravity decreases as one moves away from the earth's core. Oxygen molecules are packed tightly together at high elevations, so they cannot move. Depletion of the ozone layer has caused there to be less molecular oxygen at higher elevations.

There is less atmosphere above the air pushing down on it.

How does an open circulatory system differ from a closed circulatory system? There is no distinction between the circulating fluid and the interstitial fluid in an open circulatory system. Open circulatory systems lack hearts and rely on body movements to circulate fluids. There are no blood vessels of any sort in an open circulatory system. Open circulatory systems are found in both invertebrates and vertebrates. Open circulatory systems only transport nutrients and wastes and never transport respiratory gases.

There is no distinction between the circulating fluid and the interstitial fluid in an open circulatory system.

In what way are lymph vessels similar to veins in the cardiovascular system? They both carry fluid to the heart. They both have one-way valves. They both carry blood. They both carry fluid that is pumped by a heart. They both carry hemolymph to the body's cells.

They both have one-way valves.

Why are the walls of the alveoli so thin? Thin walls allow more alveoli to be packed into a relatively small area. Thin walls prevent the alveoli from collapsing in on themselves. Thin walls are necessary because diffusion is only effective over a very short distance. Thin walls can generate more moisture to facilitate gas exchange than thick walls can. Thin walls allow the alveoli to expand and contract more easily during breathing.

Thin walls are necessary because diffusion is only effective over a very short distance.

Fishes have: a two-chambered heart. a four-chambered heart. an open circulatory system. multiple hearts. hemolymph instead of blood.

a two-chambered heart.

Amphibians have: four distinct chambers in their heart. an open circulatory system. two partially separated circuits of bloodflow. a two-chambered heart. hemolymph instead of blood.

an open circulatory system.

In human embryos, the neural tube forms from the ________, whereas the notochord forms from the _______. ectoderm; mesoderm endoderm; ectoderm ectoderm; endoderm mesoderm; ectoderm endoderm; mesoderm

ectoderm; mesoderm

The part of the uterus that sloughs off at menstruation is a portion of the: epithelium. endothelium. endometrium. corpus luteum. oogonium.

endometrium.

Smoking leads to: reduced levels of circulating LDL. heightened immune response to pathogens. increased mucous secretions. heightened ability to filter out dirt and microorganisms from the air. increased respiratory capacity.

increased mucous secretions.

Which type of method of contraception and birth control prevents pregnancy by changing the conditions in the cervix and uterus? barrier methods hormonal methods sterilization intrauterine devices "natural" methods

intrauterine devices

Which of the following characteristics is shared by all gas exchange systems in animals? thick respiratory surface large surface area dry respiratory surface a system of internal, highly branched tubes a dedicated circulatory system to transport the respiratory gases

large surface area

In which of the following structures would oxygen-poor blood be found? left atrium left ventricle left pulmonary artery aorta right pulmonary vein

left pulmonary artery

It is more difficult to breathe at high altitudes because: the higher pressure makes it more difficult to extract oxygen from the air. less oxygen is available in a given volume of air. the diaphragm and intercostal muscles don't contract as readily at high altitudes. the colder temperatures make it more difficult to inflate the lungs. the chemical sensors that stimulate breathing are less sensitive to carbon dioxide levels in the blood at high altitudes.

less oxygen is available in a given volume of air.

Which of the following is not a component of the blood plasma? water wastes salts plasma proteins leukocytes

leukocytes

The embryos of animals tend to go through stages that resemble: the embryos of their ancestors. late-stage embryonic chickens. the specialized morphological features of the adult. slime molds. the embryos of plants.

the embryos of their ancestors.

What additional data would be most useful for determining whether the observed synchronization of menstrual cycles is a real phenomenon? the length and variability of the menstrual cycle of each individual woman in the study the age at which each woman began menstruating whether each woman's period is light or heavy the number of days of bleeding associated with each woman's menstrual cycle whether each woman uses a diaphragm or cervical cap to prevent pregnancy

the length and variability of the menstrual cycle of each individual woman in the study

After a drop of blood is pumped out of the left ventricle, which chamber will it enter first when it returns to the heart? the right atrium the left atrium the left ventricle the right ventricle both atria simultaneously

the right atrium

What is colostrum? the fluid released by a pregnant woman when her "water breaks" the hormone that causes "release" of milk in the mammary glands the substance that is released when a woman first begins to lactate a low-protein substance high in fat and sugar the hormone that increases uterine contractions in childbirth

the substance that is released when a woman first begins to lactate

What is the primary function of the semilunar valves? to regulate the volume of blood exiting the heart to regulate the volume of blood entering the heart to prevent the backflow of blood into the atria to prevent the backflow of blood into the ventricles to separate oxygen-rich and oxygen-poor blood in the heart

to prevent the backflow of blood into the ventricles