BIOM3020 (2022) Exam MCQs

Question 1

What is typically associated with hypothyroidism
(in the blood)

Answer 1

low levels of thyroid stimulating hormone (TSH) in the blood.

Question 2

Where is the first capillary bed of the hypothalamic portal vein system

Answer 2

It is found in the median eminence

Question 3

Where is the hypothalamus located

Answer 3

The hypothalamus is posterior to (i.e., behind) the lamina terminalis and anterior
commissure

Question 4

What is The primary target of the release-promoting and -inhibiting hormones of the hypothalamus

Answer 4

The anterior pituitary

Question 5

What four hormones are associated with increased insulin resistance

Answer 5

resistin, glucagon-like peptide 1 (GLP-1), placental lactogen and cortisol

Question 6

The mammalian circadian rhythm is synchronised to geophysical time by photic input from the eyes via what tract

Answer 6

the retinohypothalamic tract

Question 7

What is the mammalian circadian rhythm largely dependent on

Answer 7

the hypothalamic suprachiasmatic nucleus for normal function

Question 8

The establishment of diploidy in the newly formed zygote requires what

Answer 8

Completion of meiosis

Question 9

What is the status of the oocyte in a primordial follicle?

Answer 9

Diploid, primary oocyte arrested in prophase I

Question 10

In puberty what is the primary event underlying gonadal activation

Answer 10

Activation of pulsatile GnRH secretion

Question 11

Using an Endometrial Receptivity Assay, doctors at an IVF clinic determine that a female patient’s window of implantation is delayed. The likely therapeutic approach to this problem
would be

Answer 11

A personalized embryo transfer of frozen embryos in the next cycle.

Question 12

What are some (five) actions of the secretory phase progesterone on the female reproductive tract

Answer 12

Reduces fluid secretion, causes the cervix to become firmer, Promotes uterine spiral artery thickening and enlargement, lifts body temperature up by 0.6-1.0 degree and Drives an increase in the complexity of endometrial glands

Question 13

Can asthma worsen in pregnancy and why

Answer 13

Yes, due to viral infection

Question 14

What is erythropoietin (Epo) produced in response to

Answer 14

low tissue oxygenation, which acts on the Epo-R in red blood cell progenitors and
precursors in the bone marrow and promotes cell differentiation

Question 15

What does aldosterone bind to

Answer 15

the mineralocorticoid receptor

Question 16

Increased blood pressure (hypertension) over sustained periods of time is a primary risk factor for cardiovascular disease.
A series of compounds (such as phenoxbenzamine, guanethidine, resperine and hydralazine) were developed in the middle of the 20th century to lower blood pressure but they did not gain wide acceptance primarily because

Answer 16

they commonly lead to unpleasant side-effects

Question 17

Eric Olson’s group from Texas reported that cardiac cells express a microRNA derived from the alpha myosin heavy chain gene, which regulates the MED13 complex in the heart to control which of the following processes?

Answer 17

The rate and strength of contraction of cardiomyocytes.

Question 18

What are the two standard therapies to treat primary aldosteronism

Answer 18

Adrenalectomy and mineralocorticoid receptor antagonists

Question 19

How is primary aldosterone diagnosed, and how can medication effect the results

Answer 19

A high aldosterone to renin ratio (ARR) measurement can indicate primary
aldosteronism, but antihypertensive medications can lead to false positives and false
negatives

Question 20

The year is 2027 and you are working for a large biotech company and your role is to make a mouse model of COVID-19 infectivity. To do this, you design and produce a transgenic mouse where the endogenous mouse ACE2 gene is replaced by the human ACE2 sequence. Although you successfully produce the mouse line, you discover that the expression of the human ACE2 is 10-fold higher than expected. In characterising this transgenic mouse, which one of the following outcomes is most likely?

Answer 20

A dramatic reduction in COVID-19 infectivity

Question 21

What are the functional units of the ovary?

Answer 21

The functional units of the ovary are called follicles

Question 22

How are follicle growth and recruitment regulated?

Answer 22

Follicle growth and recruitment are regulated by hormones, primarily follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

Question 23

What is the process of oogenesis?

Answer 23

Oogenesis is the process of egg cell development. It involves meiosis, where a diploid oogonium undergoes two divisions to produce a single haploid egg cell (ovum) and polar bodies.

Question 24

What is the Hypothalamic-Pituitary-Gonadal (HPG) axis?

Answer 24

The HPG axis is a complex hormonal pathway involving the hypothalamus, pituitary gland, and gonads (ovaries in females). It regulates the production and release of reproductive hormones such as FSH and LH

Question 25

What is the 2-cell 2-gonadotropin hypothesis in the ovarian cycle?

Answer 25

The 2-cell 2-gonadotropin hypothesis explains the interactions between the ovarian follicles, FSH, LH, and the production of estrogen and progesterone during the ovarian cycle.

Question 26

What is the menstrual cycle?

Answer 26

The menstrual cycle is the monthly cycle in females, characterized by changes in the uterus and ovaries, regulated by hormonal fluctuations. It involves the shedding of the endometrium (menstruation) and the development and release of an egg (ovulation).

Question 27

Describe the hypothalamic-pituitary-gonadal (HPG) axis.

Answer 27

The HPG axis is a complex hormonal pathway that regulates reproductive functions. It involves interactions between the hypothalamus, pituitary gland, and gonads (ovaries in females). The hypothalamus produces gonadotropin-releasing hormone (GnRH), which stimulates the pituitary gland to release follicle-stimulating hormone (FSH) and luteinizing hormone (LH). These hormones, in turn, act on the gonads (ovaries) to regulate the production of sex hormones (estrogen and progesterone) and support follicle development and ovulation

Question 28

What hormone is produced by ‘H’ in the HPG axis?

Answer 28

The hormone produced by the hypothalamus (‘H’) is gonadotropin-releasing hormone (GnRH).

Question 29

What two hormones are produced by ‘P’ in the HPG axis?

Answer 29

The two hormones produced by the pituitary gland (‘P’) are follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

Question 30

What two hormones are produced by ‘G’ in females in the HPG axis?

Answer 30

In females, the two hormones produced by the gonads (ovaries) (‘G’) are estrogen and progesterone.

Question 31

What is the relationship between GnRH and FSH/LH production?

Answer 31

GnRH released by the hypothalamus stimulates the pituitary gland to produce and release FSH and LH. GnRH acts as a releasing factor for FSH and LH.

Question 32

Describe the 2-cell 2-gonadotropin hypothesis of steroid hormone production

Answer 32

The 2-cell 2-gonadotropin hypothesis explains how FSH and LH regulate steroid hormone production. The two cells involved are the granulosa cells and the theca cells. FSH stimulates the granulosa cells to convert androgens from the theca cells into estrogen. LH acts on the theca cells to promote the production of androgens, which are then converted into estrogen by the granulosa cells.

Question 33

What are the two cells involved in the 2-cell 2-gonadotropin hypothesis? What are the two gonadotropins involved?

Answer 33

The two cells involved are the granulosa cells and the theca cells. The two gonadotropins involved are follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

Question 34

List the two major ovarian hormones that regulate female reproduction. Where are they produced in the ovary? What are their primary functions in the menstrual cycle?

Answer 34

The two major ovarian hormones that regulate female reproduction are estrogen and progesterone. Estrogen is primarily produced in the granulosa cells of the developing follicles, while progesterone is produced by the corpus luteum. Estrogen is responsible for the growth and development of the uterine lining (endometrium) during the follicular phase of the menstrual cycle. Progesterone prepares the uterus for implantation and supports pregnancy during the luteal phase.

Question 35

Describe the hormonal profile during the menstrual cycle. When and why does ovulation occur? When and why does menstruation occur?

Answer 35

During the menstrual cycle, the levels of estrogen and progesterone fluctuate. In the follicular phase, estrogen levels rise, leading to the development of the uterine lining. Ovulation occurs around the mid-cycle when there is a surge in luteinizing hormone (LH), triggering the release of an egg from the ovary. In the luteal phase, progesterone levels increase, preparing the uterus for implantation. If fertilization does not occur, estrogen and progesterone levels decline, leading to menstruation, which is the shedding of the uterine lining.

Question 36

Which hormone is dominant in the follicular phase, and which hormone is dominant in the luteal phase of the menstrual cycle?

Answer 36

Estrogen is dominant in the follicular phase of the menstrual cycle, while progesterone is dominant in the luteal phase.

Question 37

What is the preovulatory follicle?

Answer 37

The preovulatory follicle is a mature follicle in the ovary that is ready to release an egg (oocyte) during ovulation

Question 38

What are the structural and molecular changes that occur during ovulation?

Answer 38

During ovulation, the preovulatory follicle undergoes structural changes, such as enlargement and thinning of the follicular wall. It also undergoes molecular changes, including an increase in proteolytic enzymes that help weaken the follicle wall for rupture

Question 39

What is the role of the oocyte and oocyte-secreted factors (OSFs) in ovulation?

Answer 39

The oocyte plays a critical role in ovulation. It secretes factors known as oocyte-secreted factors (OSFs), which stimulate changes in the surrounding cumulus cells and promote follicle rupture and cumulus-oocyte complex release during ovulation.

Question 40

What is the role of cumulus cells/cumulus expansion in oocyte maturation?

Answer 40

Cumulus cells are a specialized group of cells that surround the oocyte within the follicle. They play a crucial role in oocyte maturation. During ovulation, the cumulus cells undergo expansion, forming a protective matrix around the oocyte, allowing it to be released from the ovary. Cumulus expansion also helps facilitate the interaction between the oocyte and sperm during fertilization.

Question 41

What are the structural and molecular changes that are induced in the preovulatory follicle by the LH surge?

Answer 41

The LH surge induces several structural and molecular changes in the preovulatory follicle. Structurally, the follicle undergoes enlargement and swelling. The follicular wall becomes thinner, and there is an increased blood flow to the follicle. Molecularly, the LH surge stimulates the production of proteolytic enzymes, such as matrix metalloproteinases, which help weaken and degrade the follicular wall, leading to follicle rupture and ovulation

Question 42

What role does PGR play in ovulation?

Answer 42

PGR (progesterone receptor) plays a critical role in ovulation. It is expressed in the granulosa and cumulus cells of the preovulatory follicle. Progesterone, acting through PGR, promotes the expression of genes that are involved in follicle rupture and ovulation, including the production of proteolytic enzymes that weaken the follicular wall.

Question 43

What is the main factor produced by cumulus cells and supplied to the oocyte via gap junctions that maintains meiotic arrest?

Answer 43

The main factor produced by cumulus cells and supplied to the oocyte via gap junctions to maintain meiotic arrest is cyclic adenosine monophosphate (cAMP). Cumulus cells produce high levels of cAMP, which diffuses through gap junctions and enters the oocyte. Elevated cAMP levels in the oocyte prevent resumption of meiosis, thereby maintaining the oocyte in a prophase I arrest until ovulation.

Question 44

What is the main factor supplied by the granulosa cells to cumulus cells that results in cumulus expansion following the LH surge?

Answer 44

The main factor supplied by the granulosa cells to cumulus cells for cumulus expansion following the LH surge is hyaluronic acid. Granulosa cells produce and secrete hyaluronic acid, which accumulates in the extracellular matrix of the cumulus cell mass. Hyaluronic acid acts as a hygroscopic gel and absorbs water, leading to the expansion and dispersion of cumulus cells, creating a protective matrix around the oocyte.