Chapters 27 & 28 – Flashcards
Unlock all answers in this set
Unlock answersquestion
Gonads begin to develop
answer
5 to 6 weeks after fertilization
question
_____ determines whether an organism will be genetically male or female
answer
the sperm
question
The gene that codes for the testis-determining factor (TDF) is found in or on
answer
the Y chromosome
question
The penis is homologous to
answer
the clitoris
question
The _____ is the gonad and the _______ is the gamete
answer
Testis; sperm
question
When it is cold the _____ contracts and draws the testes closer to the body to keep them warm
answer
cremaster muscle
question
The countercurrent heat exchanger that prevents arterial blood from overheating the testes is
answer
the pampiniform plexus of veins
question
The blood testis barrier
answer
prevents antibodies in the blood from getting to the germ cells
question
By volume most of the semen is produced in the
answer
seminal vesicles
question
Why would an enlarged prostate gland interfere with urination
answer
it compresses the urethra
question
The ______ are the sites of sperm maturation and storage
answer
ductus epididymides
question
When do the testes start secreting testosterone
answer
in the first trimester of fetal development
question
Which of the following hormones directly stimulates the development of male secondary sex characteristics
answer
testosterone
question
Which of the following is an androgen
answer
testosterone
question
____ stimulates the interstitial cells of the testes to secrete _____
answer
Luteinizing Hormone(LH); testerone
question
Which hormone suppresses spermatogenesis without affecting testosterone secretion
answer
inhibin
question
The ______ have no adrogen receptors and do not respond to it
answer
germ cells
question
Testosterone inhibits
answer
gonadotropin-releasing hormone (GnRH) secretion
question
Changes called male climacteric are a consequence of
answer
decreased secretion of testosterone
question
In the process of sperminogenesis, ______ become______
answer
spermatids; spermatozoa
question
In meiosis, each parent cell produces
answer
four haploid cells
question
As a result of spermatogenesis and spermiogenesis, the final cells produced are called _____ but they and all the stages leading up to them can be called _______
answer
gametes; germ cells
question
At the end of meiosis I there are ______, whereas at the end of meiosis II there are
answer
two haploid cells; four haploid cells
question
The most important role of meiosis in sexual reproduction is
answer
that it prevents the chromosome number from doubling in each generation
question
At what stage does a developing sperm cell begin to grow a tail
answer
spermatid
question
Sperm cells get energy to power their movement from _____ contributed by the ______
answer
fructose;seminal vesicles
question
Male infertility (sterility) refers to
answer
the inability to fertilze an egg
question
The acrosome contains enzymes used to
answer
penetrate barriers surrounding the ovum
question
____ have 46 chromosomes whereas _____ have 23
answer
Primary spermatocytes; spermatids
question
A sperm count lower than _____ million sperm per mL of semen is usually associated with infertility (sterility)
answer
20 to 25
question
The _____ arteries rhythmically constrict and dilate causing the uterine mucosa to blanch and flush with blood
answer
spiral
question
After puberty the vaginal lining becomes ______ to ______
answer
stratified squamous epithelium; resist abrasion
question
The ______ is the site of attachment of the embryo
answer
endometrium
question
Mammary glands develop within the breast primarily
answer
during pregnancy
question
Breast size is determined by
answer
the amount of adipose tissue
question
The earliest sign of puberty in girls is
answer
the onset of breat development
question
_____ are feminizing hormones
answer
estrogens
question
_____ act primarily in the uterus
answer
progesterone
question
The midlife change in estrogen and progesteron is called_____ whereas the cessation of menstruation is called______
answer
climacteric;menopause
question
The ovum finalizes meiosis
answer
during fertilization
question
Most ovulation homee test kits measure _____ surge, which happens about 24 hours before ovulation
answer
LH
question
After expelling the oocyte, the follicle becomes the _____ and secretes______
answer
corpus luteum; estrogen and progesterone
question
Oogenesis starts
answer
during embryonic development
question
In the adult ovary, more than 90% of the follicles are found as
answer
primordial follicles
question
During the follicular phase, granulosa cells secrete _____ which stimulates the secretion of ______
answer
estradiol;LH
question
Which of these blood hormone levels reaches its maximum during the luteal phase
answer
progesterone
question
______ inhibits the secretion of ______ during the female sexual cycle.
answer
Estradiol and progesterone; FSH and LH
question
In early pregnancy _____ stimulates growth of the corpus luteum
answer
human chorionic gonadotropin
question
The basis of pregnancy test kits is the presence of ______ which is secreted by ______
answer
human chorionic gonadotropin (HCG); blastocyst and placenta
question
The basis for contraceptive pills is that they mimic the _____ feedback effect of _______
answer
negative;estrogens and progesterone
