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