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ANSC 4395 Exam 3 Actual Exam 2026/2027 |
Advanced Animal Science Genetics & Statistics |
Questions and Answers Graded A | Course Blueprint
Aligned | Pass Guaranteed - A+ Graded
SECTION 1: REPRODUCTIVE PHYSIOLOGY (12 Questions - 24%)
Q1: In cattle, which hormone surge triggers ovulation and subsequent corpus luteum formation?
A. Estrogen
B. Progesterone
C. Luteinizing hormone (LH)
D. Follicle-stimulating hormone (FSH)
Correct Answer: C [CORRECT]
Rationale: The LH surge from the anterior pituitary triggers final follicular maturation, ovulation
of the dominant follicle, and luteinization of granulosa and theca cells to form the corpus luteum,
which then produces progesterone to maintain the luteal phase.
Q2: Which species exhibits seasonal polyestrus with ovulation induced by coital stimulation?
A. Cattle
B. Swine
C. Sheep
D. Horses
Correct Answer: C [CORRECT]
Rationale: Sheep are short-day breeders (seasonal polyestrus) during fall/winter, and while most
ovulation is spontaneous, the ram effect can induce ovulation through pheromonal and physical
stimulation, though true coital-induced ovulation is most characteristic of cats and rabbits;
however, among livestock, sheep show the strongest seasonal breeding patterns tied to
photoperiod.
,2
Q3: The average gestation length for horses is approximately:
A. 114 days
B. 150 days
C. 283 days
D. 340 days
Correct Answer: D [CORRECT]
Rationale: Equine gestation averages 340 days (11 months), with normal range 320-360 days;
this is the longest gestation among common livestock species, requiring extended nutritional
planning and monitoring for broodmares.
Q4: In swine, the estrous cycle length is approximately:
A. 17 days
B. 21 days
C. 28 days
D. 45 days
Correct Answer: B [CORRECT]
Rationale: Swine exhibit a 21-day estrous cycle (range 18-24 days) with estrus lasting 40-60
hours; the follicular phase is 5-7 days, luteal phase 14-16 days, making synchronization
protocols effective with prostaglandins administered days 12-16.
Q5: Which hormone maintains pregnancy by suppressing luteolysis and uterine contractions?
A. Estrogen
B. Progesterone
C. Prostaglandin F2α
D. Oxytocin
Correct Answer: B [CORRECT]
Rationale: Progesterone, produced by the corpus luteum (and placenta in some species), inhibits
uterine contractions, suppresses estrus, prevents luteolysis via inhibition of oxytocin receptors,
and prepares the uterus for embryo implantation and maintenance.
Q6: SATA - Hormonal Control: Which hormones are produced by the anterior pituitary
gonadotropes? Select all that apply.
, 3
A. GnRH
B. FSH
C. LH
D. Prolactin
E. Estrogen
F. Oxytocin
Correct Answers: B, C, D [CORRECT]
Rationale: The anterior pituitary produces follicle-stimulating hormone (FSH), luteinizing
hormone (LH), and prolactin from gonadotrope and lactotrope cells; GnRH is hypothalamic,
estrogen is ovarian/ placental, and oxytocin is hypothalamic/posterior pituitary in origin.
Q7: Embryo transfer in cattle typically involves flushing embryos at what stage of development?
A. 2-cell stage (Day 1)
B. Morula to blastocyst (Days 6-8)
C. Gastrula (Day 14)
D. Fetus (Day 30)
Correct Answer: B [CORRECT]
Rationale: Bovine embryos are nonsurgically flushed from the uterus at the morula to blastocyst
stage (Days 6-8 post-ovulation) when they have descended from the oviduct; this timing
optimizes recovery rates (70-80%) and embryo viability for cryopreservation or fresh transfer.
Q8: Calculation - Estrus Synchronization: A producer wants to synchronize 50 heifers using the
Ovsynch protocol. GnRH costs $12/dose and PGF2α costs $8/dose. What is the total drug cost
per heifer?
A. $20
B. $28
C. $32
D. $40
Correct Answer: C [CORRECT]
Rationale: The Ovsynch protocol requires 2 GnRH injections (Day 0 and Day 9) and 1 PGF2α
injection (Day 7): (2 × $12) + (1 × $8) = $24 + $8 = $32 per heifer; this protocol synchronizes
ovulation without heat detection, enabling timed AI.
ANSC 4395 Exam 3 Actual Exam 2026/2027 |
Advanced Animal Science Genetics & Statistics |
Questions and Answers Graded A | Course Blueprint
Aligned | Pass Guaranteed - A+ Graded
SECTION 1: REPRODUCTIVE PHYSIOLOGY (12 Questions - 24%)
Q1: In cattle, which hormone surge triggers ovulation and subsequent corpus luteum formation?
A. Estrogen
B. Progesterone
C. Luteinizing hormone (LH)
D. Follicle-stimulating hormone (FSH)
Correct Answer: C [CORRECT]
Rationale: The LH surge from the anterior pituitary triggers final follicular maturation, ovulation
of the dominant follicle, and luteinization of granulosa and theca cells to form the corpus luteum,
which then produces progesterone to maintain the luteal phase.
Q2: Which species exhibits seasonal polyestrus with ovulation induced by coital stimulation?
A. Cattle
B. Swine
C. Sheep
D. Horses
Correct Answer: C [CORRECT]
Rationale: Sheep are short-day breeders (seasonal polyestrus) during fall/winter, and while most
ovulation is spontaneous, the ram effect can induce ovulation through pheromonal and physical
stimulation, though true coital-induced ovulation is most characteristic of cats and rabbits;
however, among livestock, sheep show the strongest seasonal breeding patterns tied to
photoperiod.
,2
Q3: The average gestation length for horses is approximately:
A. 114 days
B. 150 days
C. 283 days
D. 340 days
Correct Answer: D [CORRECT]
Rationale: Equine gestation averages 340 days (11 months), with normal range 320-360 days;
this is the longest gestation among common livestock species, requiring extended nutritional
planning and monitoring for broodmares.
Q4: In swine, the estrous cycle length is approximately:
A. 17 days
B. 21 days
C. 28 days
D. 45 days
Correct Answer: B [CORRECT]
Rationale: Swine exhibit a 21-day estrous cycle (range 18-24 days) with estrus lasting 40-60
hours; the follicular phase is 5-7 days, luteal phase 14-16 days, making synchronization
protocols effective with prostaglandins administered days 12-16.
Q5: Which hormone maintains pregnancy by suppressing luteolysis and uterine contractions?
A. Estrogen
B. Progesterone
C. Prostaglandin F2α
D. Oxytocin
Correct Answer: B [CORRECT]
Rationale: Progesterone, produced by the corpus luteum (and placenta in some species), inhibits
uterine contractions, suppresses estrus, prevents luteolysis via inhibition of oxytocin receptors,
and prepares the uterus for embryo implantation and maintenance.
Q6: SATA - Hormonal Control: Which hormones are produced by the anterior pituitary
gonadotropes? Select all that apply.
, 3
A. GnRH
B. FSH
C. LH
D. Prolactin
E. Estrogen
F. Oxytocin
Correct Answers: B, C, D [CORRECT]
Rationale: The anterior pituitary produces follicle-stimulating hormone (FSH), luteinizing
hormone (LH), and prolactin from gonadotrope and lactotrope cells; GnRH is hypothalamic,
estrogen is ovarian/ placental, and oxytocin is hypothalamic/posterior pituitary in origin.
Q7: Embryo transfer in cattle typically involves flushing embryos at what stage of development?
A. 2-cell stage (Day 1)
B. Morula to blastocyst (Days 6-8)
C. Gastrula (Day 14)
D. Fetus (Day 30)
Correct Answer: B [CORRECT]
Rationale: Bovine embryos are nonsurgically flushed from the uterus at the morula to blastocyst
stage (Days 6-8 post-ovulation) when they have descended from the oviduct; this timing
optimizes recovery rates (70-80%) and embryo viability for cryopreservation or fresh transfer.
Q8: Calculation - Estrus Synchronization: A producer wants to synchronize 50 heifers using the
Ovsynch protocol. GnRH costs $12/dose and PGF2α costs $8/dose. What is the total drug cost
per heifer?
A. $20
B. $28
C. $32
D. $40
Correct Answer: C [CORRECT]
Rationale: The Ovsynch protocol requires 2 GnRH injections (Day 0 and Day 9) and 1 PGF2α
injection (Day 7): (2 × $12) + (1 × $8) = $24 + $8 = $32 per heifer; this protocol synchronizes
ovulation without heat detection, enabling timed AI.
