Puberty MCQ's Flashcards

1
Q

A useful measure of puberty in a bull is the age at which there are sufficient sperm present in the ejaculate to successfully breed females.
True
False

A

True

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2
Q

Puberty occurs at 6-7 months of age in
heifers.
gilts.
fillies.
bulls.

A

gilts.

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3
Q

Major factors affecting the timing of puberty involve hormonal, genetics, nutrional and environmental effects.
True
False

A

True

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4
Q

In the stallion, there is an initial increase in GnRH pulse amplitude and frequency which drives maturation of Leydig and Sertoli cells but does not result in an increase in testosterone.
True
False

A

True

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5
Q

Several months before sperm production in the stallion, FSH increases without an increase in LH. The FSH effects Sertoli cell multiplication and maturation.
True
False

A

True

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6
Q

Just before sperm production in the stallion, testosterone will begin to rise.
True
False

A

True

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7
Q

In the female, a decrease in estradiol negative feedback leads to increasing GnRH pulse frequency and amplitudes until a GnRH surge occurs. The resulting LH surge causes ovulation.
True
False

A

True

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8
Q

In the female, it is estradiol exposure that causes the formation of the GnRH surge center in the hypothalamus.
True
False

A

False

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9
Q

In the male, alpha fetal protein binds testosterone and prevents testosterone from entering into the brain. The GnRH surge center will then not develop as it requires testosterone conversion to estradiol.
True
False

A

False

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10
Q

The first ovulation in the female is associated without an estrus due to lack of previous progesterone in the female. In subsequent cycles, the progesterone during diestrus sensitizes the hypothalamus so that it will respond to lower estrogen levels and cause estrus behavior when estradiol increases from the preovulatory follicle.
True
False

A

True

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11
Q

A reduction in nutrition will not change the time of puberty in cattle.
True
False

A

False

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12
Q

The difference in age of puberty of brahma and jersey cattle is an example of genetic effects on puberty.
True
False

A

True

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13
Q

In the gilt, which of the following would result in the earliest age of puberty.
2 to 3 gilts housed together
15 - 20 gilts housed together
2-3 gilts housed together and given fence line contact with a boar twice a day
15-20 gilts housed together and exposed to fence line contact with a boar once a day

A

15-20 gilts housed together and exposed to fence line contact with a boar once a day

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14
Q

In an experiment, ewe lambs were ovarectomized before puberty and then given estradiol implants. LH was monitored and found to increase at the expected age of puberty. This experiment demonstrates
that the GnRH surge center develops at puberty.
that the negative feedback of estradiol on GnRH decreases as puberty approaches.
the increase in positive feedback of estradiol as puberty approaches.
that GnRH is not regulated by ovarian steroids.

A

that the negative feedback of estradiol on GnRH decreases as puberty approaches.

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15
Q

If ewe lambs were overectomized (ovaries removed) at 18 weeks of age and then given an estradiol implant, at about 27-34 weeks of age which of the following would be true?
LH levels would increase due to a change in the sensitivity of the hypothalamus to estradiol.
LH levels would decline due to negative feedback effects of estradiol on the hypothalamus.
LH levels would remain constant but estradiol levels would begin to increase.
The ewes would ovulate.

A

LH levels would increase due to a change in the sensitivity of the hypothalamus to estradiol

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16
Q
A