BIO 163 EXAMINATION TEST 2025/2026 QUESTIONS AND
SOLUTIONS RANKED A+
✔✔Cortical reaction - ✔✔- Sperm actually penetrates through
- Prevention of fertilization of more than one sperm
- Proteins in zona pellucida crosslink to become impenetrable so that more sperm
doesn't come in, would lead to too many chromosomes in egg
✔✔Sex determination - ✔✔Males are XY, females are XX
✔✔Mullerian duct - ✔✔Forms the uterus, uterine tubes, and part of the vagina -- men
lose
✔✔Wolffian duct - ✔✔Forms epididymis, ductus deferens, and seminal vesicles in men
-- women lose
✔✔Secondary sex organs - ✔✔Other organs essential to reproduction, help transport
sperm
✔✔Secondary sex characteristics - ✔✔- Not essential for reproduction
- Physical characteristics that differentiate in sexes (height, muscle, etc)
- Maintained by sex hormones
✔✔Scrotum - ✔✔Thick external sac that surrounds testis
✔✔Outside testis - ✔✔Thin smooth muscle layer and fascia (connective tissue)
✔✔Inside scrotum - ✔✔- Cremaster smooth muscle
- Parietal tunica vaginalis
- Space
- Visceral tunica vaginalis
- Testes
✔✔Testes - ✔✔- Protected by scrotum
- Produces sperm
- Two lobes: tunica albuginea (dense connective tissue) and tunica vaginalis (visceral
layer)
✔✔Main cells in testes - ✔✔1. Interstitial leydig cells: produces testosterone
2. Spermatogonia: divide to become sperm
3. Susentacular sertoli cells: support sperms
✔✔Spermatogenesis steps - ✔✔1. Starts with immature sperm cell
2. Sustentacular cells surround developing sperm
, 3. As sperm cell travels to lumen, undergoes meiosis (single cell divides twice to
produce more genetic material)
4. Mature sperm develops tail and loses cytoplasm
5. Single spermatogonia produces four sperm cells
✔✔Hernia - ✔✔Any tissue forced out of position, can cause bulging in scrotum
✔✔Epididymis - ✔✔Function: helps sperm maturation and stores until release
- Sperm starts at head and is matured at tail
- Rete testis connects main seminiferous tubules with epididymis
- Tail joins with ductus deferens
✔✔Ductus deferens - ✔✔Function: carries sperm to ejaculatory duct
- During orgasm, peristalsis moves sperm from epididymis to ductus deferens
- Ductus deferens part of spermatic cord → cord that leaves scrotum
✔✔Ejaculatory duct - ✔✔- Short passage way between ductus and urethra
- Merges with duct of seminal vesicle to enter prostate
✔✔Male urethra - ✔✔- Passage of urine and semen
- Runs from urinary bladder to glans penis
✔✔Semen composition - ✔✔1. Seminal vesicles → sticky yellow fluid containing
enzymes
2. Prostate gland → thin milky fluid activating spermatozoa
3. Bulbourethral glands → pre-cum
✔✔Role of testoserone - ✔✔- Triggers puberty
- Maintains sex organs
- Maintains secondary sex characteristics (voice, body hair, facial hair, muscle)
- Stimulates sperm
✔✔Erections - ✔✔- Three erectile tissues supplied by cavernosal arteries
- Stimulated by parasympathetic system; vasodilation levels in penis increase, increase
blood flow
✔✔Male sexual response - ✔✔Excitement, plateau, orgasm -- emission, orgasm --
ejaculation, resolution
✔✔Excitement - ✔✔- Parasympathetic system → increased heart rate, BP, respiratory
rate
- Initiated by stimuli
- Nervous system triggers release of nitrous oxide → smooth muscle of blood vessels
relax
SOLUTIONS RANKED A+
✔✔Cortical reaction - ✔✔- Sperm actually penetrates through
- Prevention of fertilization of more than one sperm
- Proteins in zona pellucida crosslink to become impenetrable so that more sperm
doesn't come in, would lead to too many chromosomes in egg
✔✔Sex determination - ✔✔Males are XY, females are XX
✔✔Mullerian duct - ✔✔Forms the uterus, uterine tubes, and part of the vagina -- men
lose
✔✔Wolffian duct - ✔✔Forms epididymis, ductus deferens, and seminal vesicles in men
-- women lose
✔✔Secondary sex organs - ✔✔Other organs essential to reproduction, help transport
sperm
✔✔Secondary sex characteristics - ✔✔- Not essential for reproduction
- Physical characteristics that differentiate in sexes (height, muscle, etc)
- Maintained by sex hormones
✔✔Scrotum - ✔✔Thick external sac that surrounds testis
✔✔Outside testis - ✔✔Thin smooth muscle layer and fascia (connective tissue)
✔✔Inside scrotum - ✔✔- Cremaster smooth muscle
- Parietal tunica vaginalis
- Space
- Visceral tunica vaginalis
- Testes
✔✔Testes - ✔✔- Protected by scrotum
- Produces sperm
- Two lobes: tunica albuginea (dense connective tissue) and tunica vaginalis (visceral
layer)
✔✔Main cells in testes - ✔✔1. Interstitial leydig cells: produces testosterone
2. Spermatogonia: divide to become sperm
3. Susentacular sertoli cells: support sperms
✔✔Spermatogenesis steps - ✔✔1. Starts with immature sperm cell
2. Sustentacular cells surround developing sperm
, 3. As sperm cell travels to lumen, undergoes meiosis (single cell divides twice to
produce more genetic material)
4. Mature sperm develops tail and loses cytoplasm
5. Single spermatogonia produces four sperm cells
✔✔Hernia - ✔✔Any tissue forced out of position, can cause bulging in scrotum
✔✔Epididymis - ✔✔Function: helps sperm maturation and stores until release
- Sperm starts at head and is matured at tail
- Rete testis connects main seminiferous tubules with epididymis
- Tail joins with ductus deferens
✔✔Ductus deferens - ✔✔Function: carries sperm to ejaculatory duct
- During orgasm, peristalsis moves sperm from epididymis to ductus deferens
- Ductus deferens part of spermatic cord → cord that leaves scrotum
✔✔Ejaculatory duct - ✔✔- Short passage way between ductus and urethra
- Merges with duct of seminal vesicle to enter prostate
✔✔Male urethra - ✔✔- Passage of urine and semen
- Runs from urinary bladder to glans penis
✔✔Semen composition - ✔✔1. Seminal vesicles → sticky yellow fluid containing
enzymes
2. Prostate gland → thin milky fluid activating spermatozoa
3. Bulbourethral glands → pre-cum
✔✔Role of testoserone - ✔✔- Triggers puberty
- Maintains sex organs
- Maintains secondary sex characteristics (voice, body hair, facial hair, muscle)
- Stimulates sperm
✔✔Erections - ✔✔- Three erectile tissues supplied by cavernosal arteries
- Stimulated by parasympathetic system; vasodilation levels in penis increase, increase
blood flow
✔✔Male sexual response - ✔✔Excitement, plateau, orgasm -- emission, orgasm --
ejaculation, resolution
✔✔Excitement - ✔✔- Parasympathetic system → increased heart rate, BP, respiratory
rate
- Initiated by stimuli
- Nervous system triggers release of nitrous oxide → smooth muscle of blood vessels
relax
