Chapter 27 Anatomy Male Reproductive, AP Final, Meiosis

Which of these cells would contain 23 unpaired chromosomes? spermatogonia secondary spermatocytes primary spermatocytes early spermatids

early spermatids

Which male reproductive structure is NOT correctly matched with its function? seminal vesicles: produce semen bulbourethral gland: neutralize urethra before ejaculation epididymis: produce sperm ductus deferens: carry sperm toward ejaculation

epididymis: produce sperm

Which male reproductive structure is NOT correctly matched with its function? seminal vesicles: produce semen bulbourethral gland: neutralize urethra before ejaculation ductus deferens: carry sperm toward ejaculation epididymis: produce sperm

epididymis: produce sperm The epididymis is where sperm is stored and matured.

The corpus luteum prevents loss of the implanted embryo through menstruation by secreting ________.

estrogens and progesterone

Surfactant production in premature infants is rarely a factor in providing normal respiratory activity.

false

t/f The testis is divided into seminiferous tubules which contain the lobules that produce sperm and the ejaculatory duct that allows the sperm to be ejected from the body.

false

t/f Sperm are ejaculated from the corpora cavernosa of the penis.

false

t/f During implantation, the cytotrophoblast burrows into the endometrium.

false During Implantation, the syncytial trophoblast burrows into the endometrium.

t/f Human chorionic gonadotropin helps to maintain the corpus luteum for the entire gestational period.

false Human chorionic gonadotropin does feedback to the corpus luteum. However, hCG only maintains the corpus luteum for about the first 2 to 3 months of development.

t/f Fetal production of prostaglandins triggers labor.

false: Fetal cells produce oxytocin. Oxytocin triggers prostaglandin production in the placenta. Together these hormones trigger the cascade that leads to labor.

At what point is meiosis II completed for the female gamete?

fertilization

The release of __________ encourages sustentocytes to release __________.

follicle stimulating hormone, androgen binding protein

The release of __________ encourages sustentocytes to release __________. -luteinizing hormone; testosterone -inhibin; testosterone -luteinizing hormone; androgen-binding protein -follicle-stimulating hormone; androgen-binding protein

follicle-stimulating hormone; androgen-binding protein

What is the product of spermatogenesis? capacitation of sperm formation of semen formation of haploid sperm activation of spermatids

formation of haploid sperm

Which of the following is a likely result of meiosis?

four sperm, each with 23 chromosomes

What anterior pituitary-produced hormone works in conjunction with gonadal steroids to promote bone development?

growth hormone

A urine test reveals a positive result for human chorionic gonadotropin (hCG). This indicates ________ was successful.

implantation

The basic difference between spermatogenesis and oogenesis is that ________.

in oogenesis, one mature ovum is produced, and in spermatogenesis four mature sperm are produced from the parent cell

Which of the following reduces circulating blood levels of follicle-stimulating hormone (FSH) when the sperm count is high?

inhibin- Sustentocytes respond to elevated sperm counts by releasing inhibin, a hormone that suppresses release of FSH.

Which of the following would most directly interfere with sperm production?

interruption of sustentocytes' production of ABP -Sustentocytes produce ABP to keep testosterone levels high near the spermatogenic cells. Low ABP would directly affect the amount of testosterone around the spermatogenic cells.

The cells that produce testosterone in the testis are called ________.

interstitial endocrine cells

Sister chromatoids

one of the two identical parts of a duplicated chromosome in a eukaryotic cell

What event coincides with the transition from the proliferative phase to the secretory phase?

ovulation- Ovulation of the oocyte from the ovary occurs at around day 14 of the cycle, just as the uterine proliferative phase ends and the secretory phase begins.

Which hormone is NOT produced by the placenta?

oxytocin

Erection of the penis results from ________.

parasympathetic reflex

The ability of sperm cells to move along the ductus deferens is due to ________.

peristaltic contractions

The trophoblast is mostly responsible for forming the ________.

placental tissue

Which portion of the penis is removed during circumcision? glans penis prepuce (foreskin) bulb of the penis crus of the penis

prepuce (foreskin)

Sperm move to the uterine tube through uterine contractions and the energy of their own flagella. What other factor is involved in sperm movement?

reverse peristalsis of the uterus and uterine tubes

Crossing Over

the exchange of segments between chromatoids of homologous chromosomes during synapsis in prophase 1 of meiosis; also, the exchange of segments between DNA molecules in prokaryotes

Which of these male accessory ducts transports both sperm cells and urine?

urethra

Which of these male accessory ducts transports both sperm cells and urine? ejaculatory duct ductus (vas) deferens epididymis urethra

urethra

Why are the male testes located in the scrotum, outside the body? -The testes develop better outside the body. -Spermatogenesis is temperature sensitive. -Their external location is necessary for penile development. -It helps the male secondary sexual characteristics develop.

-Spermatogenesis is temperature sensitive

In males, which of the following includes the correct target and result of LH stimulation? -interstitial cells: androgen secretions -sustentacular cells: increase testosterone -sustentacular cells: increase spermatogenesis -interstitial cells: ABP secretions

-interstitial cells: androgen secretions

If a male undergoes a vasectomy, which of the following can no longer take place? -passage of sperm cells from the rete testes to the epididymis duct -passage of sperm cells from the seminiferous tubules to the rete testes -passage of sperm cells from the epididymis to the penis -passage of sperm cells from the epididymis duct to the epididymis tail

-passage of sperm cells from the epididymis to the penis

Which hormone promotes the formation of secondary sex characteristics such as the appearance of pubic, axillary, and facial hair; enhanced hair growth on the chest; and a deepening voice? -testosterone -follicle-stimulating hormone (FSH) -gonadotropin-releasing hormone (GnRH) -luteinizing hormone (LH)

-testosterone

What is the function of the blood-testis barrier? -to provide only select nutrients to the developing sperm -to ensure that semen contains only sperm and seminal fluid -to filter out male sex hormones -to prevent activation of the immune system of the male against the developing sperm

-to prevent activation of the immune system of the male against the developing sperm

How long is the secondary oocyte viable and capable of being fertilized after it is ovulated?

12-24 hours

The number of chromosomes in a human gamete is __________; this is referred to as a __________ chromosome number. 23; haploid 23; diploid 46; haploid 46; diploid

23; haploid

interphase.

A cell preparing to undergo meiosis duplicates its chromosomes during

Autosome

A chromosome not directly involved in determining the sex of an organism, in mammals, any chromosome other than X or Y.

Sex chromosome

A chromosome that determines whether an individual male or female

Tetrads

A paired set of homologous chromosomes, each composed of two sister chromatoids. Tetrads form during prophase 1 of meiosis

Gamete

A sex cell; a haploid sperm or egg. The union of two gametes of opposite sex (fertilization) produces a zygote

Nondisjunction

An accident of meiosisor mitosis in which a pair of homologous chromosomes or a pair of sister chromatids fail to seperate at anaphase

Somatic

Any cell in a multicellular organism except sperm or egg cell or a cell that develops into a sperm or egg.

Which extra-embryonic membrane is formed from the trophoblast after implantation?

Chorion The chorion is the only one of the four extra-embryonic membranes formed from the trophoblast (along with the extraembryonic mesoderm of the inner cell mass); the others form from the inner cell mass.

prophase I.

During meiosis, segments of nonsister chromatids can trade places. This recombination of maternal and paternal genetic material is a key feature of meiosis. During what phase of meiosis does recombination occur?

homologous chromosomes stick together in pairs.

During prophase I of meiosis

All but one of the following statements are true regarding the differences between early and late spermatids. Select the answer below that does not reflect a difference between early and late spermatids. Early spermatids have not undergone spermiogenesis. Early spermatids are round and have excessive cytoplasm. Early spermatids have not formed a flagella. Early spermatids have not undergone meiosis and are still diploid.

Early spermatids have not undergone meiosis and are still diploid.

All of the following statements referring to the uterine cycle are true except ________.

FSH and LH directly promote development of the uterine endometrium

What destroys the zona pellucida sperm-binding receptors?

zonal inhibiting proteins

what role does oxytocin play in promoting labor

Oxytocin stimulates the uterus to contract. - Oxytocin from fetal cells, and eventually the posterior pituitary, stimulates the uterus to contract both directly and through the release of prostaglandins.

four phases for mitosis

Prometaphase, Metaphase, Anaphase, Telophase

Which of the following serve(s) as the trigger to begin the vigorous, rhythmic contractions of true labor?

Prostaglandin release from the placenta in response to oxytocin serves as the trigger to begin the vigorous, rhythmic contractions of true labor.

Sperm is produced in the __________.

Sperm are made in the seminiferous tubules. Rather, fluid flow in the seminiferous tubules carries sperm as they are made toward an exit point from the testis.

All but one of the following statements is true with regard to the blood testis barrier. Select the one statement that is false.

The barrier is made up of astrocytes that surround blood vessels in the testis. TRUE:The barrier separates the spermatocytes dividing by meiosis from exposing their unique antigens to the immune system. Sustentocytes form the barrier with tight junctions. The barrier marks the border between the basal compartment and the adluminal compartment.

prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II.

The correct order of events during meiosis is what?

Mitosis

The division of a single nucleus into two genetically identical daughter nuclei. make up the mitotic (M) phase of the cell cycle

Which of the following will occur immediately after ovulation?

The endometrium enters its secretory phase.

Occasionally three polar bodies are found clinging to the mature ovum. One came from an unequal division of the ovum, but from where did the other two arise?

The first polar body has also divided to produce two polar bodies.

Why doesn't semen enter the urinary bladder during ejaculation?

The smooth muscle sphincter at the base of the urinary bladder closes.

Why does only one egg, rather than four eggs, develop during oogenesis, given that spermatogenesis results in four sperm formed from one stem cell?

The unequal cytoplasmic division that results in one egg and three polar bodies ensures that a fertilized egg has ample nutrients for its journey to the uterus.

The dartos and cremaster muscles are important to the integrity of the male reproductive system. Which of the following is true about the role they play?

They regulate the temperature of the testes.

Viable sperm production is optimal below the body's core temperature. True False

True

Which portion of the sperm contains the enzymes needed to penetrate the oocyte? midpiece acrosome tail head

acrosome

What would happen in a premature infant if insufficient surfactant were available?

alveolar collapse

A boy who has not passed through puberty sustains an injury to his anterior pituitary such that FSH is no longer released, but LH is normal. After he grows to maturity, one would expect that he would ________.

be sterile

Which of the following hormones stimulates the release of anterior pituitary gonadotropins?

GnRH

Which hormone maintains the viability of the corpus luteum?

HCG

Diploid

In a organism that reproduces sexually, a cell containing two homologous sets of chromosomes, one set inherited from each parent; a 2n cell has 46 chromosomes

Meiosis

In a sexually reproducing organism, the division of a single diploid nucleus into four haploid daughter nuclei. produce haploid gametes from diploid cells in the reporductive organs of the parents

Haploid

In the life cycle of an organism that reproduces sexually, a cell contains a single set of chromosomes; a n cell has 23 chromosomes

A surge in __________ directly triggers ovulation.

LH- When estrogen reaches a certain level in the body, it triggers a positive feedback loop that triggers an LH surge. This triggers ovulation.

four haploid cells.

Meiosis starts with a single diploid cell and produces

Karyotypes

a display of micrographs of the metaphase choromosomes of a cell, arranged by size and centromere position

Which of the following implants in the mucosa of the endometrium?

blastocyst, after 7 days

Which of these does NOT empty materials into the area of the prostatic urethra? prostate ductus (vas) deferens bulbo-urethral gland seminal gland

bulbo-urethral gland

Once sperm are deposited into the vagina, sperm motility must be enhanced and they must be prepared to release hydrolytic enzymes from their acrosomes. What is this process called?

capacitation

Which structure(s) of the female's external genitalia has/have erectile tissue?

clitoris

Which of the following is the first barrier that must be penetrated by the sperm in order to fertilize an oocyte?

corona radiata

What ovarian structure forms at the beginning of the secretory phase, encouraging its progress, and then degenerates just before menses?

corpus luteum The corpus luteum forms at the beginning of the secretory phase and produces hormones that support the uterus. When it degenerates about 12 days later, the uterus enters menses.

The small blue circles in the figure just inside the oocyte membrane represent vesicles containing calcium ions that are spilled into the extracellular space to prevent polyspermy. When does this take place?

just after the sperm's head enters the oocyte membrane -The release of calcium into the extracellular space occurs just after the sperm head enters the oocyte. The calcium effectively blocks sperm receptors in the zona pellucida.

Which of the following female structures is homologous to the male scrotum?

labia majora

What does the ductus arteriosus become at birth?

ligamentum arteriosum

When does the total number of chromosomes get reduced from 46 pairs to 23 individual chromosomes?

meiosis 1

Which layer of the uterus is made of smooth muscle?

myometrium

The result of polyspermy in humans is ________.

non functional zygote

Sperm is produced in the __________. ductus deferens epididymis seminiferous tubules ejaculatory duct

seminiferous tubules

The __________ is shed during each menstruation and is then regenerated by the __________.

stratum functionalis; stratum basalis

What is the testicular target for follicle-stimulating hormone (FSH)?

sustentocytes

What is the testicular target for follicle-stimulating hormone (FSH)? interstitial endocrine cells (Leydig cells) spermatogonia spermatozoa sustentocytes (Sertoli cells)

sustentocytes (Sertoli cells)

Which of the following is the site where sperm are stored until they are ejaculated? tail of the epididymis body of the epididymis rete testis seminiferous tubule

tail of the epididymis

Which of the following is/are contained within the spermatic cord? testicular arteries and veins epididymis seminiferous tubules rete testis

testicular arteries and veins

Which hormone promotes the formation of secondary sex characteristics such as the appearance of pubic, axillary, and facial hair; enhanced hair growth on the chest; and a deepening voice?

testosterone

Human egg and sperm are similar in that ________.

they have the same number of chromosomes

What is the function of meiosis? -to produce cells with double the chromosome number of the original cell -to produce genetically identical cells through the two nuclear divisions -to produce cells with half the chromosome number of the original spermatogonium or oogonium -to produce four cells, each with identical chromosomes

to produce cells with half the chromosome number of the original spermatogonium or oogonium

What cellular area shown in the figure secretes human chorionic gonadotropin (hCG)?

trophoblast is the answer the inner cell mass becomes the embryonic disc and then the embryo proper.

If gametes were diploid like somatic cells, how many chromosomes would the zygote contain?

twice the diploid number, and with every succeeding generation, the chromosome number would continue to double and normal development could not occur

Which of the following cells remains at the basal lamina to continue the pool of dividing germ cells? type A daughter cells type B daughter cells primary spermatocytes secondary spermatocytes

type A daughter cells