1. Which structures produce the male gametes?
    1. Testes
      1. The testes produce sperm, as well as the male sex hormone, testosterone.
Male_reproductive_System
  1. The structures labeled B are vas deferens, which transfer sperm from the epididymis
    1. Structure C is the urethra. It allows both semen and urine to exit the body through the penis
    2. Structure A is is the prostate gland.
    3. Structure D is the penis, which acts as both a copulating organ and a means to allow fluids (semen and urine) to leave the body.
    4. Structure E is a testis. The functions of the testes are to produce both sperm and hormones, particularly testosterone.
Male_reproductive_system
  1. Which activity would be prevented if the vas deferens were fully blocked?
    1. The transport of sperm out of the body
      1. The vas deferens allows sperm to move into the urethra. If blocked, this process could not happen.
birth control in humans
  1. Which of the following statements about the above diagram of the male reproductive system are correct?
    1. A is the ureter.D is the urethra.
    2. F is the testis where sperm is synthesized.
    3. B is the prostate gland. C is one of the seminal vesicles. 
    1. E is the vas deferens that carries sperm from the testis to the urethra.
  2. On average, 1.5 to 5 ml of semen is released in a single ejaculation. Even though sperm cells constitute only 2 to 5 percent of semen, their absolute number is in the millions. What are the characteristics of sperm?
    1. A sperm cell mainly consists of genetic material and a tail.
      1. A sperm cell consists mainly of genetic material that carries information and a tail.
    2. Sperm is delivered from the testes through the vas deferens.
      1. The vas deferens is the tube that carries sperm from the testes to the urethra.
  3. Which of the following statements about the human testes are true ?
    1. The synthesis of testosterone takes place inside the testes.
      1. Testosterone is synthesized by Leydig cells in the testes.
    2. The synthesis of sperm takes place inside the testes.
      1. Male germ cells in the testes develop into sperm cells.
  4. The male human reproductive system consists of the testes and the male accessory glands. Which of the following statements about male accessory glands are true?
    1. Male accessory glands contribute to semen.
      1. Secretions from the prostate gland and seminal vesicle glands contribute to the composition of semen.
    2. The secretions of prostate gland and seminal vesicles make semen fluid and provide nutrition
      1. The seminal vesicles secretions include fructose and nourishment for sperm cells. Secretions from the prostate gland contribute to the fluid in semen
    3. The prostate gland and seminal vesicles are found outside the testes.
      1. The prostate gland and seminal vesicles are found outside the testes along the path of vas deferens.
  5. Sperm cells present in semen can only survive for a few minutes once released outside the body. However, inside the female reproductive tract, sperm cells can survive up to five days. Which of the following is a correct statement about sperm?
    1. Sperm fertilizes the egg in the oviduct.
      1. Fertilization of the egg by sperm happens in the oviduct.
  6. Which of the following statements correctly describe the structure and function of the testes?
    1. The testes are located outside the abdominal cavity in order to enable sperm synthesis.
      1. The synthesis of sperm is carried out 2 -3 degrees below body temperature. The testes are located in the scrotum, outside the abdominal cavity, in order to provide this cooler environment.
    2. Sperm is synthesized in the testes.
      1. Male germ cells present in the testes develop into sperm cells through cell division.
  7. Vasectomy is a surgical procedure in which the vas deferens, the tube that carries sperm from the testes to the urethra, is cut and blocked so that no sperm is ejaculated. The ejaculation of a male who has undergone vasectomy contains secretions only from the male accessory glands. Which of the following statements correctly describe the structure and function of male accessory glands?
    1. The male accessory glands contribute to the contents of semen.
      1. Secretions from the prostate and seminal vesicle glands contribute to semen.
    2. The seminal vesicles secretions include fructose and nourishment for sperm cells. Secretions from the prostate gland contribute to the fluid in semen.
      1. The secretions from prostate gland and seminal vesicles make semen fluid and provide nutrition to sperm cells.

Female reproductive system:

Female_Reproductive_System
  1. Structure 2 is the cervix, which connects the uterus and the vagina. Female gametes are produced in the ovaries
  2. Structure 5 is the uterus, which is where early human development occurs. It supports a growing fetus
  3. Structure 4 is an oviduct (fallopian tube). It acts as the site of fertilization. It also functions as a passageway between an ovary and the uterus.
  4. Structure 3 is an ovary. It acts as the site of female gamete production. Urine is stored in the urinary bladder.
  5. Structure 1 receives the penis during intercourse and acts as the birthing canal.
  1. true of the uterus
    1. It is the site of early human development.
      1. A fertilized egg attaches itself to the lining of the uterus, ultimately developing into an embryo that will continue to grow into a baby.
  2. Which structure in the female reproductive system produces eggs?
    1. Ovary
      1. The ovaries of a female produce gametes called eggs.
Female_reproductive_system
  1. Which part of the female reproductive system has been correctly labeled in the image above?
    1. A is the oviduct or fallopian tube. D is the cervix.
    2. E is the vagina, the passage into which sperm is released during intercourse.
    3. C is the uterus, where the fetus develops during pregnancy.
    4. B is one of two ovaries, which contain and release egg cells.
  2. What roles do the ovaries play in the female reproductive system?
    1. The ovaries secrete sex hormones.
      1. The ovaries secrete female sex hormones such as estrogen and progesterone.
    2. The ovaries produce eggs.
      1. The ovaries produce female germ-cells, or, eggs.
  3. What happens to the uterus lining when fertilization does not occur?
    1. The lining breaks down and leads to menstruation.
      1. The lining is broken down and expelled from the body as menstrual blood. This process is called menstruation.
  4. What are the functions of the ovaries?
    1. The ovaries produce eggs.
      1. The ovaries produce female germ-cells known as eggs.
    2. Ovaries produce estrogen.
      1. Estrogen, a female sex hormone, is produced by the ovaries.

Spermatogenesis:

  1. A diploid primary spermatocyte divides to form 2 secondary spermatocytes. These secondary spermatocytes divide again to form 4 spermatids. If the primary spermatocyte had 24 Chromosomes, how many chromosomes would each spermatid have?
    1. 12
      1. Diploid (2n) primary spermatocytes undergo meiosis I to form haploid (n) secondary spermatocytes with 12 chromosomes. They, in turn, produce haploid spermatids through meiosis II.
  2. A diploid primary spermatocyte divides to form 2 secondary spermatocytes. These secondary spermatocytes divide again to form 4 spermatids. If the primary spermatocyte had 40 chromosomes, how many chromosomes would each spermatid have?
    1. 20
      1. Diploid (2n) primary spermatocytes undergo meiosis I to form haploid (n) secondary spermatocytes with 20 chromosomes. They, in turn, produce haploid spermatids through meiosis II.
  3. Once spermatogenesis begins, a series of processes occur constantly inside the testes. One such process is called spermiation, which involves mature sperm cells. Which of the following events occur during spermiation?
    1. Sperm cells are released from seminiferous tubules.
      1. Sperm cells are ejected from the seminiferous tubules during spermiation.
  4. A lab technician studies microscope slides containing cross sections of a testis. He is asked to identify and label spermatogonia in the slides. Which of the following characteristics should he look for, in order to correctly identify these cells?
    1. Located in seminiferous tubules.
      1. Spermatogonia are found in the inner walls of seminiferous tubules.
    2. Immature germ cells undergoing mitosis.
      1. Spermatogonia mitotically divide to maintain a stock of immature germ cells that can later develop into sperm.
  5. A primary spermatocyte divides to produce two secondary spermatocytes. If each secondary spermatocyte has 23 chromosomes, how many chromosomes did the primary spermatocyte have?
    1. 23
      1. Haploid (n) secondary spermatocytes are produced by meiotic, or reduction division of diploid (2n) primary spermatocytes.
  6. A primary spermatocyte divides to give rise to two secondary spermatocytes. If the primary spermatocyte had 46 chromosomes, how many chromosomes will each secondary spermatocyte have?
    1. Diploid (2n) primary spermatocytes divide meiotically to produce haploid (n) secondary spermatocytes.
  7. Spermiogenesis is the process by which spermatids get differentiated into sperm cells. The sperm then undergo a few more processes, including spermiation. What happens during spermiation?
    1. Sperm cells are released from seminiferous tubules.
      1. Spermiation is the term used to describe the release of sperm from the seminiferous tubules.
  8. An anatomy student wants to learn to identify spermatogonia. She looks through slides containing cross-sections of a testis. Which of the following characteristics should she look for in order to correctly identify these cells?
    1. Located in seminiferous tubules
      1. Spermatogonia are found in the inner walls of seminiferous tubules.
    2. Immature germ cells undergoing mitosis.
      1. Spermatogonia mitotically divide to maintain a stock of immature germ cells that can later develop into sperm.
  9. A primary spermatocyte divides to produce two secondary spermatocytes. If each secondary spermatocyte has 23 chromosomes, how many chromosomes did the primary spermatocyte have?
    1. 23
      1. Haploid (n) secondary spermatocytes are produced by meiotic, or reduction division of diploid (2n) primary spermatocytes.

Structure and properties of sperm

  1. A sperm bank receives 3samples from 3 different men. The samples are tested for motility and morphology (shape, size, etc). The test results are listed in the table below.
DonorMotility (%percent)Morphology (%percent)
A5715
B3170
C4865

The bank will only accept samples that meet the minimum requirements to ensure fertility. Which of the samples is the bank most likely to accept?

  1. C- A sperm sample with at least 40% motility and at least 60% normal morphology is likely to ensure fertility.
  1. A sperm bank receives 3 samples from 3 different men. The samples are tested for motility and morphology (shape, size, etc). The test results are listed in the table below
DonorMotility (%percent)Morphology (%percent)
A2235
B6570
C4830
  1. The bank will only accept samples that meet the minimum requirements to ensure fertility. Which of the samples is the bank most likely to accept?
    1. B – A sperm sample with at least 40%, percent motility and at least 60% normal morphology is likely to ensure fertility.
  2. Forensic investigators use alternate sources of light to detect semen in crime scenes. Semen contains seminal vesicle secretions which glow under UV light, and can thus be spotted when illuminated. What are some of the other components of semen that investigators could identify with tests?
    1. Secretions of prostate glands – Secretions from the prostate glands contribute to the seminal plasma that makes up semen.
    2. Sperm cells
      1. Hundreds of millions of sperm cells make up a large part of semen.
  3. Globozoospermia is a rare disorder that can cause infertility in men. This condition leads to the development of abnormal sperm cells that have rounded heads without any acrosomes. Which of the following statements explain why these abnormal sperm cells cause infertility?
    1. They will not be able to penetrate egg cells.
      1. Acrosomes contain enzymes that help penetrate the outer wall of egg cells. Thus, sperm cells without acrosomes will not be able to enter and fertilize egg cells.
  4. Once ejaculated, human sperm cells propel themselves along the female reproductive tract to reach their target. A single sperm cell is only about 50 μm long and yet it can travel several centimeters until it reaches an egg cell. How are sperm cells able to swim so far?
    1. They are powered by mitochondria in the midsection.
      1. The midsection or middle piece of the sperm cell contains several mitochondria, which provide the energy it needs to swim to an egg cell.
  5. Forensic investigators can detect semen at crime scenes with something called an AP test. This test looks for high levels of acid phosphatase, an enzyme released by the prostate gland, that makes up semen along with other secretions. What are some of the other components of semen that investigators could identify with tests?
    1. Secretions of vas deferens
    2. Secretions of seminal vesicles
    3. Sperm cells
  6. The success rates of in vitro fertilization increase when eggs are injected with sperm cells that have undergone a process known as the acrosome reaction. This process involves the acrosome, the cap-like structure present on the head of sperm cells. Why would activating the acrosome improve chances of fertilization?
    1. The acrosome releases enzymes that allow sperm cells to enter egg cells.
      1. The acrosome contains enzymes that allow the sperm cell to get past the hard outer covering of an egg cell. Thus, the acrosome reaction improves chances of fertilization.
  7. Human sperm cells travel very large distances (relative to their own size) in order to reach an egg cell. What part of their structure provides them with this ability?
    1. Mitochondria in the midsection.
      1. The midsection of a sperm cell contains several mitochondria, which provide the energy it needs to swim to an egg cell.
Sperm_structure

Oogenesis:

  1. Oogonia divide mitotically to give rise to primary oocytes, which in turn undergo meiosis I to form secondary oocytes. Secondary oocytes later complete the second meiotic division to give rise to ova. If ova are haploid in nature, which of the following statements about ploidy is true?
    1. Secondary oocytes are haploid Haploid (n)
      1. secondary oocytes are formed from meiotic division of diploid (2n) primary oocytes. They, in turn, form haploid ova through meiosis II.
  2. Polar bodies are often studied and used in genetic screens. The main advantage of these studies is that although viable eggs are not damaged, valuable information on maternal contribution to the embryo can be obtained. Which of the following statements explains how polar bodies are formed?
    1. Division of a primary oocyte
      1. When a primary oocyte undergoes meiosis I, it produces both a secondary oocyte and the first polar body.
    2. Division of a secondary oocyte
      1. When a secondary oocyte completes meiotic division, it produces both the ovum and second polar body.
  3. Gamete mother cells are formed in fetal ovaries during embryonic development. Which of the following events also occur in the fetus before it is born?
    1. Formation of primary oocytes.
      1. Oogonia begin the process of meiosis I and get arrested at prophase I. These cells are known as primary oocytes.
  4. Which of the following structures contains a secondary oocyte?
    1. Tertiary follicle
      1. Several layers of granulosa cells enclose an oocyte within a cavity to form a follicle. Tertiary follicles contain secondary oocytes.
  5. A diploid primary oocyte undergoes meiosis I to form a secondary oocyte. The secondary oocyte later divides to give rise to an ovum. If the primary oocyte had 60 chromosomes, how many chromosomes will the ovum have?
    1. 30
      1. Diploid (2n) primary oocytes give rise to haploid (n) secondary oocytes which, in turn, divide to form ova with the same number of chromosomes (n).
  6. Polar bodies are not fully understood, but can be studied to understand the nature of oocytes. What is the relationship between a polar body and an oocyte?
    1. They are both daughter cells produced by meiotic division.
      1. When a primary oocyte divides, it forms the secondary oocyte and first polar body. Similarly, the secondary oocyte produces an ovum and second polar body.
  7. A few million oogonia are formed in each ovary during embryonic development of a female fetus. Which of the following events also occur in the fetus before it is born?
    1. Meiotic arrest of primary oocytes
      1. Primary oocytes enter meiosis I, but are arrested at prophase I until puberty.
  8. The appearance of oocytes changes as oogenesis progresses, and cells divide and get rearranged. Which of the following statements correctly describes the characteristics of secondary oocytes?
    1. Graafian follicles contain secondary oocytes.
      1. Several layers of granulosa cells enclose an oocyte within a cavity to form a follicle. The tertiary, or Graafian follicle contains the secondary oocyte.

Menstrual cycle events:

  1. Simi uses birth control pills to prevent ovulation. Each pill contains a combination of hormones that stop ovaries from releasing eggs. One day, Simi uses her last pill and realizes that she’s forgotten to buy more. Assuming she has a regular 28-day cycle, after roughly how many days will Simi start to ovulate again?
    1. 14
      1. Ovulation occurs midway through the cycle due to a spike in hormone levels, usually around the 14th day.
  2. If the egg released during the ovarian cycle is not fertilized, it triggers the degradation of the corpus luteum, which brings about the next phase in the cycle. What function does the corpus luteum perform, while waiting for the egg to be fertilized?
    1. It maintains the endometrial lining.
      1. The corpus luteum secretes large amounts of progesterone to maintain the endometrium, ready for implantation of the fertilized egg.
  3. Non-primate mammals undergo what is known as the estrous cycle, during which they “go into heat” and are ready to mate. In these animals, if fertilization of the released egg does not occur, the endometrium is simply absorbed back into the system. What happens in humans when the released egg is not fertilized?
    1. The endometrial lining is broken down and ejected from the body.
      1. The thickened endometrial lining, along with its blood vessels, is broken down and ejected through the vagina as menstrual flow.
  4. The follicular phase follows the menstrual phase, and continues until ovulation occurs. Which of the following events occur in this period?
    1. Development of follicles.
      1. Primary follicles develop all the way into Graafian follicles, ready for ovulation.
    2. Thickening of the endometrium.
      1. The follicular phase is also known as the proliferative phase, because the endometrial lining of the uterus begins to thicken again.
  5. Sally buys an ovulation kit to predict when she is likely to ovulate, in order to improve her chances of getting pregnant. The kit predicts ovulation within a window of 1-1.5 days. Assuming she has a regular 28 day menstrual cycle, when should Sally use her kit?
    1. Between days 12−15
      1. Ovulation usually occurs midway through the cycle, around day 14. The kit will detect a surge in hormone levels, which indicates that an egg is about to be released.
  6. The endometrium proliferates in preparation for the fertilized egg to attach to it. If fertilization does not occur, it is broken down and shed from the body. Which of the following structures maintain the endometrial lining?
    1. Corpus luteum
      1. The corpus luteum readies and maintains the endometrium for pregnancy. If there is no pregnancy, it degenerates and causes the endometrium to break down.
  7. The corpus luteum degrades if fertilization does not occur, leading to a dip in hormone levels. Which of the following events happens as a result of this change?
    1. The uterus lining is shed.
      1. The uterus lining, or endometrium, disintegrates and is shed as menstrual blood.
  8. As the proliferative phase begins, there is a spike in the levels of pituitary and ovarian hormones. Which of the following events happen due to this hormonal change?
    1. Follicular development.
      1. The proliferative, or follicular phase, is when primary follicles develop all the way into Graafian follicles.
    2. Thickening of endometrial lining.
      1. The endometrial lining proliferates and begins thickening during this phase.

Fertilization and implantation:

  1. After copulation, sperm cells are directed towards the egg cell by hormones released by cells surrounding the oocyte. Which of the following sites will a sperm cell have to reach, in order to fertilise the egg?
    1. Fallopian tube
      1. Fertilizations occurs in a region of the Fallopian tube known as the ampulla.
  2. Several sperm cells race towards an egg cell. One cell reaches the egg slightly ahead of the others. What must this sperm cell do to prevent its competitors from entering the egg?
    1. Cross the zona pellucida.
      1. Crossing the zona pellucida induces a reaction that cross-links the membrane and makes it impermeable to other sperm cells.
  3. A zygotę is formed when a sperm cell and ovum fuse together. Which of the following statements correctly describes how this occurs?
    1. The oocyte inside the egg cell divides to produce the ovum when a sperm cell enters.
      1. The secondary oocyte within the egg cell divides meiotically to give rise to an ovum. The sperm then fuses with it to form the zygote.
  4. A sperm cell carrying a Y chromosome fuses with an ovum. What are the odds of the zygote developing into a female child?
    1. 0%
      1. All ova carry only X chromosomes. If a sperm carrying Y fuses with an ovum, the child will be male (XY).
  5. The morula is named for its resemblance to a mulberry, from the Latin word morus. Which of the following statements correctly describes the structure of the morula?
    1. Embryo with 16 blastomeres.
      1. The zygote divides to form structures with increasing numbers of cells, or blastomeres. Morula refers to the stage with 8-16 blastomeres.
  6. A series of events leads up to implantation of the embryo in the endometrium. Identify the statement that correctly describes one of these events
    1. The blastocyst gets covered by rapidly dividing uterine cells.
      1. Rapidly dividing cells in the endometrium cover the blastocyst, thus embedding it in the uterus and leading to implantation.
  7. Which of the following statements correctly describes cleavage?
    1. Mitotic division of the zygote.
      1. The single-celled zygote begins to divide and develop into a larger structure through mitotic division, or cleavage.
  8. Blocked Fallopian tubes are sometimes the cause of infertility in women. Which of the following statements correctly explains why this issue would prevent pregnancy?
    1. It prevents fertilisation.
      1. Fertilisation occurs in the ampullary region of the Fallopian tube. Blockage in this area will not allow sperm cells to meet the egg cell.
  9. Egg cells can undergo a process known as the cortical reaction. This process triggers a change in the structure of the zona pellucida, making it so hard that sperm cells can no longer enter. What induces this process to occur?
    1. Sperm cell crossing the zona pellucida
      1. Once a sperm cell crosses the zona pellucida, it induces the cortical reaction to prevent others from doing the same.
  10. Which of the following events occurs before a zygote can be formed?
    1. Meiotic division of the secondary oocyte.
      1. The successful entry of a sperm cell into the egg cell induces the secondary oocyte to meiotically divide to produce the ovum.
  11. A sperm cell carrying an X chromosome fuses with an ovum. What are the odds of the zygote developing into a female child?
    1. 100%
      1. All ova carry only  X  chromosomes. A sperm with an X chromosome will form an XX zygote, or a female child.
  12. As the zygote develops, it divides and increases in size from a single cell. At one point, it becomes a ball of  8−16 cells. What is this structure called?
    1. Morula
      1. A morula is formed when the zygote divides into a solid structure with about  16 blastomeres.
  13. The morula develops into the blastocyst, as it moves into the uterus. Which of the following events happen next, leading up to implantation?
    1. The blastocyst becomes embedded in the endometrium.
      1. Cells of the endometrium divide rapidly and cover the blastocyst, embedding it in the uterus.
    2. The inner cell mass differentiates into the embryo.
      1. The blastocyst develops an outer trophoblast and an inner cell mass. The latter develops into the embryo.
  14. Which of the following statements about cleavage of the zygote is true?
    1. It leads to embryonic stages with 2,4,8, and 16 blastomeres.
      1. Blastomeres are daughter cells formed by mitotic cleavage of the zygote.

Menstrual cycle hormones

  1. The release of an egg from the ovary, or ovulation, is triggered by a change in specific hormone levels. Which of the following statements correctly describes this change?
    1. Sharp increase in Luteinizing hormone (LH)
      1. LH levels surge around day 14  of the cycle, leading to the rupture of the Graafian follicle, and the release of the oocyte within.
  2. The image below depicts the changes in hormone levels over the course of the menstrual cycle.
Menstrual_cycle_hormone
  1. Match the labeled hormones with their corresponding properties
labelhormone
ALH
BFSH
Cestrogen
Dprogesterone
Menstrual_cycle_hormones
labelhormone
Atriggers ovulation
Bstimulates follicular development
Covarian hormone
Dsecreted by the corpus luteum
Menstrual_cycle
menstrual_cycle
  1. When the corpus luteum stops releasing a certain hormone, it triggers the beginning of the menstrual phase. Identify this hormone from the options listed below.
    1. Progesterone When the corpus luteum degenerates, it stops releasing progesterone, leading to the breakdown of the endometrial lining during menstruation.
  2. During the follicular phase, both ovarian and pituitary hormone levels change. Which of the following statements correctly describes these changes during the follicular phase?
    1. Estrogen levels increase
      1. Estrogen levels rise during this phase, stimulating the endometrium to proliferate again.
    2. Follicle stimulating hormone (FSH) levels increase
      1. FSH levels rise, stimulating the development of follicles in the ovary.
  3. A sharp rise in the levels of luteinizing hormone (LH) triggers an important event in the ovarian cycle. Which of the following statements correctly describes this event?
    1. Rupture of the Graafian follicle
      1. LH levels surge around day 14 of the cycle, leading to the rupture of the Graafian follicle, and the release of the oocyte within.
  4. The menstrual phase is triggered by hormonal changes that occur when fertilization does not happen. Which of the following statements correctly describes the hormonal change that induces menstruation?
    1. Decrease in progesterone levels.
      1. In the absence of fertilization, the corpus luteum degenerates, and thus stops releasing large amounts of progesterone.
  5. During the proliferative phase, two main developments occur. The uterine wall begins to thicken again, and primary follicles start changing into secondary, and eventually tertiary/Graafian follicles. Which of the following statements correctly explain the hormonal changes that cause these developments?
    1. Follicle stimulating hormone (FSH) levels increase.
    2. Estrogen levels increase.

Pregnancy, placenta and hormones:

  1. Which of the following hormones does the placenta produce?
    1. Progesterone is released to nourish the embryo and prevent contractions of the uterus.
    2. Human chorionic gonadotropin (hCG)
      1. hCG prevents the degeneration of the corpus luteum. Most pregnancy tests look for hCG.
  2. Pregnancy is accompanied by several changes in hormonal levels, which support fetal growth and metabolism. Which of the following statements about these hormones is true?
    1. Levels of prolactin and thyroxine increase several fold in maternal blood
      1. Prolactin and thyroxine levels rise to help the fetus develop and prepare the mother for lactation.
  3. The development of chorionic villi forms a connection between the developing embryo and the mother, eventually leading to placenta formation. How do these villi help connect mother and child?
    1. They project from the trophoblast into the uterus.
      1. The outer layer of the embryo, or the trophoblast, sends finger-like projections into the uterine wall. This leads to the development of the placenta.
  1. The placenta is a temporary organ that connects the developing fetus in the womb to the mother. Which of the following statements correctly describes a feature of the placenta?
    1. Exchange of glucose, oxygen and waste materials through the placenta.
      1. Glucose and oxygen pass from the mother’s blood to the fetus through the placenta. Waste products like carbon dioxide and urea pass from the embryo to the mother’s blood.
  2. The developing fetus can develop passive immunity, through maternal antibodies that pass through the placenta. Which of the following functions are also enabled by the placenta?
    1. Removal of carbon dioxide from the fetus.
      1. The placenta allows carbon dioxide generated by the fetus to diffuse through to be collected by maternal blood vessels.
  3. Many cultures consider the placenta to have special properties, or to have a role in the development of the child after birth. Which of the following functions does the placenta carry out during pregnancy?
    1. Supply of oxygen to the fetus.
      1. Maternal blood carries oxygen to the placenta, where it diffuses through to the fetus.
human_foetus
  1. Relaxin is a hormone produced by both the ovary and the placenta in pregnant women. Which of the following hormones are produced by the placenta alone?
    1. Human placental lactogen (hPL)
      1. hPL is useful for embryonic development and metabolism.
    2. Estrogen
      1. Estrogen levels increase several-fold in pregnant women, and contribute to the enlargement of the uterus and breasts during this period.
  2. Although there is no conclusive evidence for what causes morning sickness, some people believe hormonal changes, including production of human chorionic gonadotropin (hCG) might be responsible for such symptoms. Which of the following hormone changes also occur only during pregnancy?
    1. Several fold increase in levels of cortisol.
      1. Cortisol levels rise during pregnancy, and help with the development of the fetus.
  3. Some pregnancies develop a complication known as placenta accreta, in which the placenta attaches to the myometrium, or muscular lining of the uterus. Which of the following statements correctly describes how the placenta is formed in normal pregnancies?
    1. The trophoblast extends villi into the endometrial wall.
      1. In normal pregnancies, chorionic villi from the trophoblast of the embryo invade the endometrial wall, forming the placenta.