Question 1

Which of the following statements about the trophoblast is false?&#10;A) It develops into the embryo proper&#10;B) It helps form the placenta&#10;C) It invades the endometrium during implantation&#10;D) It is the outer layer of cells around the blastula&#10;E) It secretes human chorionic gonadotropiin

Accepted Answer

The trophoblast does not develop into the embryo proper, but instead forms the extra-embryonic membranes that surround and support the developing embryo, including the placenta. The embryo proper develops from the inner cell mass of the blastula.

Question 2

What cells are found between the basement membrane and the epithelium of the lactiferous ducts?&#10;A) Columnar cells&#10;B) Cuboidal cells&#10;C) Fat cells&#10;D) Myoepithelial cells&#10;E) Secretory cells

Accepted Answer

Myoepithelial cells are found between the basement membrane and the epithelium of the lactiferous ducts. These cells have contractile properties and are important in milk ejection during lactation.

Question 3

Which part of the spermatozoa contains digestive enzymes that aid in fertilization?&#10;A) Acrosome&#10;B) Basal plate&#10;C) End piece&#10;D) Neck&#10;E) Tail

Accepted Answer

The acrosome is a structure located in the head section of the spermatozoa, which contains digestive enzymes that are necessary for fertilization. These enzymes help to break down the outer layer of the egg, allowing the sperm to penetrate and fertilize it. The other parts of the spermatozoa, including the basal plate, neck, end piece, and tail, are not involved in the fertilization process.

Question 4

Where does fertilization usually occur?&#10;A) Cervix&#10;B) Ovary&#10;C) Oviduct&#10;D) Uterus&#10;E) Vagina

Accepted Answer

Fertilization usually occurs in the oviduct (also known as the fallopian tube), where the egg is carried from the ovary after ovulation. The sperm must travel through the cervix and into the uterus in order to reach the oviduct and fertilize the egg. However, fertilization itself typically occurs in the oviduct.

Question 5

What structure secretes estrogen and progesterone for approximately 3 months following fertilization?&#10;A) Corpus albicans&#10;B) Corpus luteum&#10;C) Mature follicle&#10;D) Placenta&#10;E) Tunica albuginea

Accepted Answer

The corpus luteum secretes estrogen and progesterone for the first 3 months of pregnancy until the placenta takes over hormone production.

Question 6

Following fertilization and after about 3 days of cell division, the developing organism is considered a ____ as it moves along the uterine tube toward the uterus.&#10;A) Blastula&#10;B) Fetus&#10;C) Gastrula&#10;D) Morula&#10;E) Zygote

Accepted Answer

After about 3 days of cell division following fertilization, the developing organism is a morula. It is a solid ball of cells that is about the same size as the original zygote but with more cells. It moves along the uterine tube toward the uterus. Once the morula reaches the uterus, it undergoes further cell division and forms a blastula, which is a hollow ball of cells. Later, the blastula develops into a gastrula, which has three distinct layers and will eventually form the various tissues and organs of the body. The fetus is the term used for the developing organism after about 9 weeks of gestation.

Question 7

The opening of the uterus into the vagina is the _____.&#10;A) Cervix&#10;B) Infundibulum&#10;C) Ovary&#10;D) Oviduct&#10;E) Uterine tube

Accepted Answer

The opening of the uterus into the vagina is called the cervix. The infundibulum, ovary, oviduct, and uterine tube are all parts of the female reproductive system, but they do not refer to the opening of the uterus into the vagina.

Question 8

Rapid cell division without organismal growth is called&#10;A) Cleavage&#10;B) Implantation&#10;C) Meiosis&#10;D) Mitosis&#10;E) Oogenesis

Accepted Answer

Cleavage is rapid cell division that occurs immediately after fertilization, where the zygote undergoes a series of mitotic divisions without any increase in overall size of the embryo. This process eventually leads to the formation of the blastula. Implantation is the process by which the blastula adheres to and penetrates the uterine lining. Meiosis is a type of cell division that results in the formation of haploid gametes. Mitosis is a type of cell division that allows for growth and repair of tissues, and for asexual reproduction in some organisms. Oogenesis is the process by which female gametes (oocytes) are produced.

Deck 23: Fertilization, Placentation, and Lactation