a and p final exam

The period of gestation that is characterized by rapid fetal growth and adipose tissue deposition is the ________ trimester(s).

third

The outer layer of cells separating the outside world from the blastocoele is called the

trophoblast

What must be present for albinism to occur?

two recessive alleles

In males, meiosis involves ________ cycle(s) of cell division and produces ________ cells, or gametes, each containing 23 individual chromosomes.

two; four

The yolk stalk and body stalk fuse during week five, forming the ________.

umbilical stalk

During the secretory phase of the uterine (menstrual) cycle,

uterine glands enlarge.

The organ that provides mechanical protection and nutritional support for the developing embryo is the

uterus

Which structure(s) in the female has(have) the same embryological origin as the corpus spongiosum in males?

vestibular bulbs

The first extraembryonic membrane to appear is the ________.

yolk sac

Which extraembryonic membrane is an important site of blood cell production?

yolk sac

Which of the following is a major hormonal event at the onset of puberty?

The anterior lobe of the pituitary gland becomes more sensitive to GnRH.

Choose the correct statement regarding semen.

The fluid component of semen is a mixture of glandular secretions with a distinct ionic and nutrient composition.

The most common viable chromosome abnormality is ________.

Trisomy 21

By week three of development, the mesoderm extends along trophoblast structures, forming the ________.

chorionic villi

The division of the zygote into two blastomeres occurs during

cleavage

Which process, one that occurs during the first trimester, is characterized by the zygote becoming a "pre-embryo"?

cleavage

The anterior enlargement of erectile tissue in females is known as the

clitoris

The female structure that is derived from the same embryonic structures as the penis in males is the

clitoris

When the alleles of a gene are both expressed equally, the alleles show a mechanism of inheritance called ________.

codominance

A relatively common inherited autosomal recessive disorder is ________.

cystic fibrosis

The muscle in the wall of the scrotum is the

dartos muscle

The stage of labor during which the fetus begins to shift toward the cervical canal is the

dilation stage

A(n) ________ allele will always be expressed regardless of what the other allele happens to be.

dominant

Oogenesis begins

during embryonic development.

Gastrulation produces an oval, three-layered sheet known as the

embryonic disc

Which uterine layer consists of a superficial functional zone and a deeper basilar zone?

endometrium

"Hot flashes" in menopause typically begin while levels of ________ are declining.

estrogen

Just prior to menses,

estrogen and progesterone levels drop

Identify the notable risk factor associated with breast cancer.

family history of breast cancer

If an X-carrying sperm fertilizes an egg, the resulting zygote will be ________.

female only

The shallow recess surrounding the cervical protrusion is known as the

fornix

During female sexual arousal, the ________, which resemble the male bulbo-urethral glands, discharge their secretions near the vaginal entrance

greater vestibular glands

The conversion of mammary glands from resting to active states requires the presence of both placental hormones and ________.

growth hormones, prolactin, and thyroid hormones

If an individual carries two different alleles of the same gene, he or she is ________ for the trait determined by that gene.

heterozygous

Paired chromosomes are called

homologous chromosomes.

The elastic epithelial fold of variable size, which partially blocks the entrance to the vagina, is called the ________.

hymen

Fertilization of the ovum usually occurs

in the upper 1/3 of the uterine tube

Female orgasm is accompanied by peristaltic contractions of the uterine and vaginal walls and by rhythmic contractions of which of the following muscles?

ischiocavernosus and bulbospongiosus

Which of the following is(are) described as an adipose-containing, fleshy structure that encircles and partially conceals external genital structures?

labia majora

During pregnancy,

maternal tidal volume increases.

At which gestational age do basic heart structures, major blood vessels, lymph nodes, and ducts form?

month 2

The mesoderm forms (the)

muscle

The period from birth to the end of the first month is known as (the) ________.

neonatal period

Parasympathetic innervation of the penile arteries involves neurons that release ________ at their synaptic terminals.

nitric oxide

Capacitation

occurs after spermatozoa mix with secretions of the seminal glands.

Contraction of the cremaster muscle

occurs when the testes are suddenly exposed to a cold environment

The process of oogenesis produces ________ viable ovum/ova.

one

Sperm carry

one X or one Y sex chromosome.

Ova carry

one X sex chromosome.

Distortion of the cervix stimulates maternal release of which hormone?

oxytocin

In females, engorgement of the erectile tissues of the clitoris is due to ________.

parasympathetic activation

If dozens of sperm did not release hyaluronidase, no single sperm could

penetrate the corona radiata.

The layer of visceral peritoneum of the uterine wall is called the ________.

perimetrium

Spermatozoa are moved along the ductus deferens by

peristaltic contractions.

In polygenic inheritance,

phenotypic characteristics are determined by interactions among several genes.

Which of the following phenotypic characteristics is an example of "codominance"?

presence of A or B antigens on red blood cell membranes

What is the function of the gonads?

produce the gametes and hormones

The most commonly prescribed oral contraceptives use small amounts of estrogen, or only

progesterone.

The principal hormone secreted by the corpus luteum, which prepares the uterus for pregnancy, is

progesterone.

The chorionic villi

provide the surface area for gaseous exchange between fetal and maternal bloodstreams.

An allele that is ________ will be expressed only if it is present on both chromosomes of a homologous pair

recessive

Which of the following is a hormone secreted by both the placenta and the corpus luteum during pregnancy, and functions in suppressing the release of oxytocin?

relaxin

Slender, tightly coiled tubules originate at the seminiferous tubules and form a maze of passageways called the

rete testis

The ejaculatory duct in males is produced by the junction of the ductus deferens with the ________.

seminal gland duct

The vagina

serves as a passageway for the elimination of menstrual fluids.

Hemophilia is a(n) ________.

sex-linked trait

In spermiogenesis, the small, relatively unspecialized gametes that physically mature are called

spermatids

The physical maturation of sperm is called ________.

spermiogenesis

Which of the following results from endodermal contributions?

stem cells that produce gametes

Which of the following is a recessive trait?

straight hair

The hormone responsible for initiating a male's sexual maturation and the appearance of secondary sex characteristics is

testosterone

If the parents are AA and aa, the offspring are all expected to be

Aa

Neural tube formation occurs during which gestational age?

1 month

The human genome consists of approximately 3.2 billion base pairs. Protein-coding genes represent ________ of the total genome.

2

The average length of the uterine (menstrual) cycle is ________ days.

28

The following is a list of structures of the male reproductive tract.1 - ductus deferens2 - urethra3 - ejaculatory duct4 - epididymisThe correct order in which spermatozoa pass through these structures from the testes to the penis is

4, 1, 3, 2.

Human somatic cells contain ________ chromosomes.

46 or 23 pairs of

The fluids contributed by the seminiferous tubules and epididymis account for about how much of the volume of semen?

5%

________ is characterized by failure of the testes to descend into the scrotum by the time of birth.

Cryptorchidism

Which statement regarding placental circulation is true?

Deoxygenated maternal blood re-enters the mother's venous system through small uterine veins.

Regarding hormones and body temperature, which statement is true?

During the follicular phase, when estrogen is the dominant hormone, the resting body temperature is 0.3∘C lower than it is during the luteal phase.

During the male climacteric,

FSH and LH levels rise.

Which statement regarding the neonatal renal system is true?

Glomerular filtration is normal.

Roughly twelve days after ovulation, the corpus luteum becomes nonfunctional and hypothalamic production of ________ increases.

GnRH

Which of the following is an autosomal dominant inherited disorder?

Huntington's disease

Which anterior pituitary lobe hormone targets the interstitial cells of the testes?

LH

________ are produced at the end of the meiotic divisions in the seminiferous tubules.

Spermatids

Which statement is true regarding conjoined twins?

Splitting of the blastomeres or of the embryonic disc is not complete.

Genes that appear on the X chromosome are said to be ________.

X-linked

The normal pair of sex chromosomes in males is

XY

The vestibule is

a central space surrounded by the labia minora.

A blastocyst is

a hollow ball of cells.

The extraembryonic membrane that forms the urinary bladder is the

allantois.

In adult males, the testes secrete ________.

androgens

The interstitial cells of the testes secrete which reproductive hormone(s)?

androgens

The reddish brown skin that surrounds the nipple is called the

areola.

The small, paired glands at the base of the penis that produce a lubricating secretion are the

bulbourethral glands.

To become active, motile, and fully functional, sperm cells must undergo the process of ________.

capacitation

The tubular structure of the uterus that projects a short distance into the vagina is called the

cervix

Which extraembryonic structure is created as migrating mesodermal cells form a layer beneath the trophoblast, separating it from the blastocoele?

chorion