1.
Gametes are produced by
Correct Answer
E. Gonads
Explanation
Gametes, which are reproductive cells (sperm and eggs), are produced by the gonads. The gonads are the primary reproductive organs in both males and females, such as the testes in males and the ovaries in females. These organs are responsible for the production of gametes through a process called gametogenesis. Therefore, the correct answer is gonads.
2.
Eggs and sperm cells have
Correct Answer
D. 23 chromosomes
Explanation
Eggs and sperm cells have 23 chromosomes. This is because during the process of meiosis, the number of chromosomes is halved in order to create haploid cells, which only contain one set of chromosomes. When an egg and sperm cell fuse during fertilization, they combine their sets of chromosomes to form a complete set of 46 chromosomes in the resulting zygote. Therefore, eggs and sperm cells individually have 23 chromosomes.
3.
Zygote with the genotype YO will
Correct Answer
A. Die
Explanation
A zygote with the genotype YO will die because the presence of the Y chromosome is necessary for the development of a male individual. Without the Y chromosome, the zygote will not be able to develop into a male or a female and will not survive.
4.
a zygote with the genotype XO will
Correct Answer
E. A and b
Explanation
A zygote with the genotype XO will develop into a female and have Turner syndrome. Turner syndrome is a genetic condition that affects females and is characterized by the absence or partial absence of one of the X chromosomes. This results in various physical and developmental abnormalities. Therefore, the zygote with the genotype XO will develop into a female with Turner syndrome.
5.
The fold of the skin that cover the tip of the penis
is
Correct Answer
C. Prepuce
Explanation
The prepuce is the fold of skin that covers the tip of the penis. It is also commonly known as the foreskin. During circumcision, the prepuce is removed. It serves to protect the glans of the penis and keep it moist. The prepuce is retractable and can be pulled back to expose the glans for cleaning.
6.
Indifferent gonads develop into testes under the
influence of
Correct Answer
E. None of the above
Explanation
The indifferent gonads develop into testes under the influence of the SRY gene, which is responsible for the production of the testis-determining factor (TDF). This factor triggers the development of the testes and the production of androgens, such as testosterone, which are responsible for the differentiation of male reproductive organs. LH, estrogen, and peptide or protein hormones do not directly influence the development of testes. Therefore, the correct answer is "none of the above".
7.
The erectile tissue that surrounds the urethra is
Correct Answer
D. Corpus spongiosum
Explanation
The corpus spongiosum is the erectile tissue that surrounds the urethra. It is located on the ventral side of the penis and extends from the bulb of the penis to the glans penis. During sexual arousal, the corpus spongiosum fills with blood, helping to maintain the rigidity of the penis and allowing for the passage of semen through the urethra during ejaculation.
8.
in the condtion known as crpytorchidism
Correct Answer
B. The testes fail to descend into the scrotum
Explanation
Cryptorchidism is a condition where the testes fail to descend into the scrotum. This means that instead of being in the scrotum, the testes remain in the abdomen or the inguinal canal. This condition can lead to infertility as the temperature in the scrotum is necessary for the production of sperm. The other statements mentioned in the question, such as the foreskin being surgically removed, the testes being surgically removed, and the prostate glands being enlarged, are not related to cryptorchidism.
9.
The small paired glands at the base of the penis that
produce lubricating secretion are the
Correct Answer
E. Bulbourethral glands
Explanation
The small paired glands at the base of the penis that produce lubricating secretion are the bulbourethral glands. These glands are also known as Cowper's glands and they are responsible for producing a clear lubricating fluid that helps to neutralize the acidity of the urethra and provide lubrication during sexual arousal. This fluid is released prior to ejaculation and helps to enhance sperm motility and protect the sperm from the acidic environment of the urethra.
10.
Sperm production occurs in
Correct Answer
E. The seminiferous tubules
Explanation
Sperm production occurs in the seminiferous tubules, which are located in the testes. These tubules are responsible for the production of sperm cells through a process called spermatogenesis. The other options listed are not involved in sperm production. The ductus deferens is responsible for transporting sperm from the testes to the urethra, the rete testis is a network of tubules that connects the seminiferous tubules to the epididymis, the seminal vesicle produces seminal fluid, and the epididymis is responsible for storing and maturing sperm.
11.
Interstitial cells produce
Correct Answer
A. Androgens
Explanation
Interstitial cells, also known as Leydig cells, are located in the testes in males and are responsible for producing androgens, which are male sex hormones. These hormones, such as testosterone, play a crucial role in the development and maintenance of male reproductive organs and secondary sexual characteristics. Androgens are also involved in regulating sperm production, sexual function, and overall male physiology. Therefore, the correct answer is androgens.
12.
the structure
that carries sperm from the epididymis to the urethra is the
Correct Answer
A. Ductus deferens
Explanation
The correct answer is ductus deferens. The ductus deferens is a tube that carries sperm from the epididymis to the urethra. It is a part of the male reproductive system and plays a crucial role in the transportation of sperm for ejaculation.
13.
The role of the pituitary hormone FSH in males is to
Correct Answer
D. Initiate sperm production in the testes
Explanation
The pituitary hormone FSH (follicle-stimulating hormone) plays a crucial role in initiating sperm production in the testes. FSH stimulates the Sertoli cells, which are located in the seminiferous tubules of the testes, to support and nourish developing sperm cells. This hormone is responsible for the maturation and release of sperm cells into the reproductive system, thus playing a vital role in male fertility and reproductive function.
14.
the cervix is
Correct Answer
B. The neck of the uterus
Explanation
The correct answer is "The neck of the uterus." The cervix is a narrow passage that connects the uterus to the vagina. It acts as a protective barrier and helps to keep the uterus closed during pregnancy. It also plays a role in the menstrual cycle by allowing the passage of menstrual blood from the uterus to the vagina.
15.
The structure
that transport the ovum to the uterus is the
Correct Answer
B. Fallopian tube
Explanation
The fallopian tube is the correct answer because it is the structure that transports the ovum from the ovary to the uterus. It is a narrow tube that connects the ovary to the uterus and is lined with cilia that help move the ovum along. The fallopian tube is where fertilization of the ovum typically occurs before it implants in the uterus.
16.
the average length of the menstrual cycle is
Correct Answer
A. 28 days
Explanation
The average length of the menstrual cycle is typically 28 days. This is considered the standard length for a menstrual cycle, although it can vary from person to person. The menstrual cycle is counted from the first day of one period to the first day of the next period. A cycle that is consistently shorter or longer than 28 days may indicate a hormonal imbalance or other health issue.
17.
The surge in LH that occurs during the middle of the
ovarian cycle triggers
Correct Answer
D. Ovulation
Explanation
During the middle of the ovarian cycle, there is a surge in LH (luteinizing hormone) levels. This surge in LH is responsible for triggering ovulation. Ovulation is the process in which a mature egg is released from the ovary and can be fertilized by sperm. Therefore, the correct answer is ovulation.
18.
______ decreases
ovarian follicle sensitivity to FSH.
Correct Answer
B. Anti-Mullerian hormone
Explanation
Anti-Mullerian hormone decreases ovarian follicle sensitivity to FSH. This hormone is produced by the granulosa cells of the ovarian follicles and inhibits the recruitment and development of new follicles. By reducing the sensitivity of ovarian follicles to FSH, Anti-Mullerian hormone helps regulate the growth and development of follicles, ensuring that only a limited number of follicles mature during each menstrual cycle. This helps maintain the balance between follicular development and ovulation.
19.
The principle hormone secreted by the corpus luteum is
Correct Answer
B. Progestorone
Explanation
The corpus luteum is a temporary structure that forms in the ovary after ovulation. Its main function is to produce the hormone progesterone, which is essential for preparing the uterus for pregnancy and maintaining a pregnancy if fertilization occurs. Progesterone helps to thicken the uterine lining and inhibit contractions of the uterus, ensuring a suitable environment for implantation and development of the fertilized egg. Therefore, the correct answer is Progesterone.
20.
menstruation is
triggered by a drop in the level(s) of
Correct Answer
C. Estrogen and progesterone
Explanation
Menstruation is triggered by a drop in the levels of estrogen and progesterone. These hormones play a crucial role in the menstrual cycle. During the menstrual cycle, the levels of estrogen and progesterone rise and fall. When these hormone levels drop, it signals the shedding of the uterine lining, resulting in menstruation. This drop in estrogen and progesterone levels is necessary for the body to prepare for a new menstrual cycle and potential pregnancy.
21.
at approximately day 15, when the implanted blastocyt
differentiates into distinct layers of cells, the mass is called an:
Correct Answer
A. Embryo
Explanation
At approximately day 15, after the blastocyst implants, it starts to differentiate into distinct layers of cells. This stage is known as the embryo. The embryo is the early stage of development in which the cells begin to specialize and form different tissues and organs. It is the precursor to the fetus, which is the later stage of development. The blastocyst is the stage prior to implantation, and the placenta is the organ that forms during pregnancy to provide nutrients and oxygen to the developing embryo/fetus.
22.
During the first few weeks of pregnancy the embryo
receives nutrients from the
Correct Answer
C. Uterine wall
Explanation
During the first few weeks of pregnancy, the embryo receives nutrients from the uterine wall. The uterine wall is rich in blood vessels and provides a nourishing environment for the developing embryo. It allows for the exchange of oxygen, nutrients, and waste products between the mother's bloodstream and the embryo, ensuring its growth and development. The placenta and umbilical cord play a role in nutrient and oxygen exchange later in pregnancy, but during the initial weeks, the uterine wall is primarily responsible for providing the necessary nutrients to the embryo.
23.
the corpus luteum in a nonpregnant woman usually lasts
about
Correct Answer
E. 12 days
Explanation
The corpus luteum in a nonpregnant woman usually lasts about 12 days. The corpus luteum is a temporary structure that forms in the ovary after ovulation. It is responsible for producing progesterone, which is important for preparing the uterus for potential implantation of a fertilized egg. If fertilization does not occur, the corpus luteum will degenerate after around 12 days, leading to a decrease in progesterone levels and the shedding of the uterine lining during menstruation. This cycle typically repeats every month in nonpregnant women.
24.
Polyspermy in humans results in
Correct Answer
C. A nonfunctional zygote
Explanation
Polyspermy in humans refers to the fertilization of an egg by multiple sperm. In normal circumstances, only one sperm should fertilize the egg to form a functional zygote. However, if polyspermy occurs, it usually leads to the formation of a nonfunctional zygote. This is because the presence of multiple paternal genomes disrupts the normal development and genetic balance required for the zygote to develop into a viable embryo. As a result, the nonfunctional zygote is unable to develop further and eventually fails to implant or survive.
25.
Which of the
following hormones is NOT produced by the placenta?
Correct Answer
A. )Luteinizing hormone
Explanation
Luteinizing hormone is not produced by the placenta. The placenta is responsible for producing hormones such as human placental lactogen (hPL), relaxin, human chorionic gonadotropin (hCG), and progesterone. Luteinizing hormone is primarily produced by the pituitary gland in the brain and plays a role in the menstrual cycle and ovulation.
26.
During gestation, powerful uterine contractions are
suppressed by elevated levels of
Correct Answer
A. Progesterone
Explanation
Progesterone is the correct answer because it is a hormone that plays a crucial role in maintaining pregnancy. It helps in the development of the uterine lining and prevents uterine contractions that could potentially lead to miscarriage. Elevated levels of progesterone during gestation suppress uterine contractions, ensuring the stability of the pregnancy. Estrogen, oxytocin, and prostaglandins also have roles in pregnancy, but they do not directly suppress uterine contractions like progesterone does.
27.
the hormone primarily responsibe for milk synthesis is
Correct Answer
C. Estrogen
Explanation
Estrogen is the hormone primarily responsible for milk synthesis. Estrogen plays a crucial role in the development of mammary glands and stimulates the growth of milk ducts. It also promotes the production of prolactin, another hormone involved in milk production. During pregnancy, estrogen levels increase, preparing the breasts for lactation. After childbirth, estrogen levels decrease, allowing prolactin to stimulate milk production. Oxytocin, on the other hand, is responsible for milk ejection or the let-down reflex. Progesterone and growth hormone do not directly contribute to milk synthesis.
28.
The following is a list of structures of the male
reproductive tract.
1. Ductus
deferens
2. Urethra
3. Ejaculatory
duct
4. Epididymus
Identify the order in which the sperm pass
through these structures from the testes to the penis
Correct Answer
D. 4, 1, 3, 2
Explanation
The correct order in which sperm pass through the structures of the male reproductive tract from the testes to the penis is 4, 1, 3, 2. First, sperm pass through the epididymis where they mature and gain the ability to swim. Then, they move through the ductus deferens, a muscular tube that carries sperm from the epididymis to the ejaculatory duct. Next, they pass through the ejaculatory duct, which connects the ductus deferens to the urethra. Finally, they exit through the urethra, which is the tube that carries both urine and semen out of the body.
29.
in the follicular phase of the ovarian cycle, the ovary Is
Correct Answer
A. Maturing a follicle
Explanation
During the follicular phase of the ovarian cycle, the ovary is maturing a follicle. This is the phase where a follicle, which contains an immature egg, develops and grows in response to hormonal signals. The follicle produces estrogen, which helps to prepare the uterus for potential pregnancy. Once the follicle is fully matured, it will rupture and release a mature egg, which is then ready for fertilization.
30.
Hemophilia, color blindness, and Duchenne muscular
dystrophy occur more often in male than females. Why?
Correct Answer
B. These diseases develop due to the lack of estrogen and progesterone