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Parturition and lactation - class-XI

Description: parturition and lactation
Number of Questions: 73
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Tags: biology animal physiology zoology menustral cycle in human human reproduction
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Milk secreted from the cells of alveoli of mammary lobes reaches nipple through lactiferous duct (L), mammary duct(M), mammary tubule (T) and mammary ampulla (A) in the following order

  1. TMAL

  2. MTLA

  3. MTAL

  4. ATML


Correct Option: A
Explanation:
  • Mammary glands or breasts are modified sweat glands that lie over the pectoral muscles. Each breast has a broad multiporous tip called nipple for the release of milk. A circular pigmented area called areola lies below it. Each breast contains 15-20 glandular lobes separated from one another by dense connective tissue and adipose tissue. Each lobe is further made of many lobules having glandular or secretory alveoli.
  • The cells of alveoli produce milk which is stored in the cavities or lumens of alveoli. Alveoli open into mammary tubules and then into mammary ducts. Mammary ducts form a mammary ampulla from which a lactiferous duct develops. Each lobe produces a separate lactiferous duct. The various lactiferous ducts open at the nipple by separate pores.
So, the correct answer is 'TMAL'.

Delivery of developed fetus is scientifically called ______________.

  1. Parturition

  2. Oviposition

  3. Abortion

  4. Ovulation


Correct Option: A
Explanation:

Parturition is the act of expelling the full-term young one from the mother's uterus at the end of gestation. Gestation (pregnancy) is completed in about 266 days from the mother's last menstruation.

Given below are three statements each with one or two blanks. Select the option which correctly fills up the blanks in, any two statements.
(A) In human beings, menstrual cycle ceases around 50 years of age; this is termed as  (i) .
(B) The milk produced during the initial few days of lactation is called  (i)  which contains several  (ii)  absolutely essential to develop resistance for the new-born babies.
(C) At the completion of the  (i)  division the primary oocyte divides into secondary oocyte and  (ii) .

  1. (A)-(i) menarche; (B)-(i) lactation, (ii) minerals

  2. (B)-(i) colostrum, (ii) antibodies, (C)-(i) first meiotic, (ii) first polar body

  3. (A)-(i) menopause; (C)-(i) second meiotic, (ii) second polar body

  4. (A)-(i) menopause; (B)-(i) corpus luteum, (ii) antibodies


Correct Option: B
Explanation:

The mammary glands of the female undergo differentiation after the pregnancy and starts producing milk towards the end of it, called lactation and the milk produced during these initial few days is referred to as colostrum. This contains many antibodies that is essential for the new born babies to develop resistance against any pathogen attack or disease. During oogenesis the gamete mother cell undergoes meiosis division to form the primary oocyte and this further divides into the secondary oocyte and a polar body by means of an unequal division. 

So, the correct option is ' (B)-(i) colostrum, (ii) antibodies, (C)-(i) first meiotic, (ii) first polar body'.

Intensely lactating mothers do not generally conceive due to the

  1. Suppression of gonadotropins

  2. Hypersecretion of gonadotropins

  3. Suppression of gametic transport

  4. Suppression of fertilization


Correct Option: A
Explanation:
Presence of prolactin hormone in the blood of lactating mothers suppresses the release of gonadotropins (FSH and LH) from the pituitary gland. Gonadotropins are required for ovulation to occur. Thus, in the absence of gonadotropins, ovum is not released and hence chances of fertilisation are nil upto 6 months following parturition (if the mother is regularly breast-feeding). Therefore, intensely lactating mothers do not generally conceive.
So, the correct answer is 'Suppression of gonadotropins'.

Which hormone stimulates the secretion of milk from female?

  1. Oxytocin

  2. Progesterone

  3. LH

  4. Prolactin


Correct Option: D
Explanation:

 Prolactin hormone is secreted by pituitary gland it stimulates the secretion of milk from mammals. It rises only when a baby suckles. Hormone oxytocin cause tiny muscles around the alveoli to squeeze the milk by using small tubes called milk ducts. Oxytocin is also responsible for contraction of uterus muscles, during and after birth. Prolactiiin and Oxytocin help the mother to form an emotional bond with her baby. Progesterone regulates the growth in size of alveoli and lobes. Estrogen stimulates the milk duct system to grow. Follicle stimulating hormone, luteinizing hormone and human chorionic gonadotropin control the level of estrogen and progesterone production.    

Select the correct statement.

  1. hPL plays a major role in parturition.

  2. Fetus shows movements first time in the ${7}^{th}$ month of pregnancy.

  3. Signal for parturition comes from fully developed fetus and placenta.

  4. Embryo's heart is formed by the ${2}^{nd}$ month of pregnancy.


Correct Option: C
Explanation:

Parturition, also called birth or childbirth, process of bringing forth a child from the uterus, or womb. The prior development of the child in the uterus is described in the article human embryology. The process and series of changes that take place in a woman’s organs and tissues as a result of the developing fetus are discussed in the article pregnancy. Parturition is induced by a complex neuroendocrine mechanism. The signals for parturition originate from the fully-developed foetus and the placenta which requires the release of oxytocin from the posterior lobe of the maternal pituitary.

So the correct option is 'signal for parturition comes from fully developed foetus and placenta'.

Corpus luteum develops from

  1. Oocyte

  2. Nephrostome

  3. Graafian follicle

  4. None of the above


Correct Option: C
Explanation:

After ovulation the lining of the (graafian) follicles grow inward, forming corpus luteum (yellow body), which temporary function as endocrine tissue. It secrete estrogen and progesterone, which stops additional ovulation, and thickening of uterine wall. If pregnancy does not occur within 14 days corpus luteum degenerates and menstruation follows.

Gestation period is the duration

  1. Of fertilization

  2. Between egg growth and ovulation

  3. Between fertilization and parturition

  4. None of the above


Correct Option: C
Explanation:
The gestation period is the duration between fertilization and parturition. Gestation period is the time in which a foetus develops, beginning with fertilization and ending at birth.
Fertilization is the process of fusion of two types of gametes (spermatozoon and ovum), so as to form a diploid zygote.
Parturition is the act of expelling the full term young ones from the mother's uterus at the end of gestation.

Gestation period in human beings is about 

  1. 10 weeks

  2. 28 weeks

  3. 32 weeks

  4. 36 weeks


Correct Option: D
Explanation:

Gestation (pregnancy) is completed in about 266 days from the mother's last menstruation. The gestation period of human beings is 270 days to 280 (approximately). It is usually about 266 days i.e., 36 weeks.

The process of delivery of the feotus is called 

  1. Parturition

  2. Implantation

  3. Fertilisation

  4. Lactation

  5. Ovulation


Correct Option: A
Explanation:

Parturition can be defined as the act of expelling the full term young ones from the mother's uterus at the end of the gestation period. In other words, the process of delivery of the fetus is known as parturition.

Delivery of developed foetus is

  1. Ovulation

  2. Oviposition

  3. Parturition

  4. Abortion


Correct Option: C
Explanation:

The delivery of the developed foetus after 9 months is known as parturition. Ovulation is the release of the secondary oocyte from the ovary. 

Oviposition is known as the egg-laying stage.
Abortion is the ending of the pregnancy before time. If it is abrupt then it is known as a miscarriage but if the abortion is surgical and through pills, it is known as induced abortion.
So, the correct option is 'Parturition'.

Thick yellow, high protein fluid produced by mammary glands of a woman during first $2-3$ days after child birth is

  1. Meconium

  2. Hymen

  3. Cumulus oophorus

  4. Colostrum


Correct Option: D
Explanation:
The mammary glands undergo differentiation during pregnancy and start producing milk towards the end of pregnancy by the process called lactation.
The milk produced during the initial few days of lactation – colostrum. It is thick and yellow in colour. It contains several antibodies essential to develop resistance for new-borns.
so, the correct option is 'Colostrum'.

State whether the following statements are true or false.
Prolactin stimulates milk secretion and growth of breast.

  1. True

  2. False


Correct Option: A
Explanation:
Prolactin regulates the growth of the mammary glands and formation of milk in them. Prolactin has a wide variety of effects. It stimulates the mammary glands to produce milk (lactation). Increased serum concentrations of prolactin during pregnancy cause enlargement of the mammary glands and prepare for milk production.
So, the correct option is 'True'.

Breast feeding suspends pregnancy due to

  1. Post pregnancy lower levels of FSH and LH

  2. Post pregnancy higher levels of FSH and LH which puts a negative check on ovulation

  3. Inhibiting the release of FSH by prolactin and thus countering the effects of FSH on the ovarian follicles

  4. Increasing the release of inhibin by prolactin and thus countering the effects of FSH on the ovarian follicles


Correct Option: C
Explanation:

The hypothalamus secretes the Gonadotropin-releasing hormone which is responsible for menstruation sequence. The GnrRH repressed by the prolactin hormone, which encourages the production of milk. Without the GnRH release, the menstrual cycle wont begin a new event of pregnancy.

As long as prolactin level are high, GnRH generally won't be release. Now GnRH is responsible for the release of the follicular stimulating hormone. The hormone FSH is responsible for the formation of ovarian follicle. So, as GnRH is stopped there will be an inhibition in the release of FSH by prolactin and thus thus it counter the effects of FSH on the ovarian follicle. So, there will be a delay in ovulation that will automatically prevent pregnancy. 
So, the correct option is 'Inhibiting the release of FSH by prolactin and thus countering the effects of FSH on the ovarian follicle'.

Which of these is not an important component of the initiation of parturition in humans?

  1. Synthesis of prostaglandins

  2. Release of oxytocin

  3. Release of prolactin

  4. Increase in estrogen and progesterone ratio


Correct Option: C
Explanation:

  • Parturition is a phenomenon of giving birth. It is a process of delivering a child from the womb to the outside. It is usually initiated by the release of oxytocin hormone. 
  • This hormone increases the contraction of uterine muscles. Prostaglandins are synthesized and released in response to the oxytocin hormone. Also, an increase in estrogen and progesterone ratio indicates the initiation of the parturition process. 
  • Prolactin hormones are released after the parturition in order to secrete the milk from the mammary gland.

Thus, the correct answer is 'Release of prolactin.'

Which of the following statement is incorrect regarding the parturition?

  1. The signals of parturition originate from fully developed foetus and ovary

  2. Relaxin hormine relaxes the pubic symphysis during parturition

  3. Thyroxine is a main parturition hormone

  4. HCG is responsible for labour pain


Correct Option: C
Explanation:

Parturition is the process of giving birth to the child.

A)its signal starts from the mature fetus.
B)Relaxin hormone relaxes the pubic symphysis during parturition by softening and lightening pubic symphysis.
C)Oxytocin is the main parturition hormone.
D)HCG is responsible for labor pain.
So the correct option is 'Thyroxine is the main parturition hormone'.

Foetal ejection reflex triggers the release of 

  1. Prolactin by maternal pituitary

  2. Prolactin by foetal pituitary

  3. Oxytocin by foetal pituitary

  4. Oxytocin by maternal pituitary


Correct Option: D

The haemoglobin of a human foetus

  1. Has a higher affinity for oxygen than that of an adult

  2. Has a lower affinity for oxygen than that of the adult

  3. Its affinity for oxygen is the same as that of an adult

  4. Has only $2$ protein subunits instead of $4$


Correct Option: A
Explanation:
  • The oxygen is needed for aerobic respiration and diffuses from a region of high to low concentration from the mother's blood to the blood of the foetus. 
  • The haemoglobin of the foetus has a higher affinity for oxygen than that of adult haemoglobin and so the efficiency of exchange is increased

So, the correct answer is 'Has a higher affinity for oxygen than that of an adult'

If a couple has four girls ,the probability of fifth child being male is _________.

  1. $50\%$

  2. $25\%$

  3. $75\%$

  4. $100\%$


Correct Option: A
Explanation:

The gender of the consecutive children does not depend on each other. So, every time the couple has a kid, there is equal chances of them having a girl or a boy. Therefore, the probability would be 50% reasonably. 

In human beings, pregnancy lasts for $9$ months. The gestation period of dog, elephant, cat and cow is given. Which of the following is wrong match?

  1. Animal - Dog, Gestation period - $60-65$ days

  2. Animal- Elephant, Gestation period - $607-641$ days

  3. Animal - Cat, Gestation period - $52-65$ days

  4. Animal - Cow, Gestation period - $330-345$ days


Correct Option: A
Explanation:

Gestation length varies by age of dam, breed, and sex of the calf. Gestation length ranges from 279 to 287 days. For most breeds, 283 days is common. In dogs, the entire gestation period is approximately nine weeks, or 63 days, although it can range from 58 to 68 days. Cat pregnancy normally lasts between 63 to 67 days, but it can be tough to know exactly how long a cat is pregnant for. The cat gestation period can vary from as short as 61 days to as long as 72 days. so, 'the correct option is-Animal - Cow, Gestation period - 330−345 days'

In which month, can the foetal movements be observed?

  1. $1^{st}$

  2. $5^{th}$

  3. $3^{rd}$

  4. $4^{th}$


Correct Option: B
Explanation:
During the first pregnancy, it may not feel that the baby will move until closer to 25 weeks. By the second pregnancy, some women start to feel movements as early as 13 weeks. The first kicking activity is seen in the 5th month.
So, the correct option is '5th'. 

Find the correct statements.
a. By the end of $2^{nd}$ month of pregnancy, foetus limbs and digits develop
b. By the end of $1^{st}$ trimester, most of the major organs are formed in basic form.
c. Signal for parturition originates from fully developed foetus and placenta
d. Lactation starts after the end of pregnancy period

  1. a & c

  2. c & d

  3. b, c & d

  4. a, b, c & d


Correct Option: D
Explanation:

It has been observed that by the end of the second month of pregnancy period, the foetus develops limbs and digits. Also, by the end of the first trimester (12 weeks), most of the major organs are developed, for instance, the limbs and external genital organs. The signals for parturition derives from the fully developed foetus and the placenta that further leads to mild uterine contraction referred to as foetal ejection reflex. By the end of pregnancy, the mammary glands initiate producing milk by the lactation process. 

So, the correct answer is option D, a, b, c & d. 

The process of releasing the ripe female gamete(ovum) from the ovary is called?

  1. Parturition

  2. Ovulation

  3. Fertilisation

  4. Implantion


Correct Option: A

Milk ejection hormone in a lactating mother is?

  1. Prolactin

  2. Oxytocin

  3. Progesterone

  4. Estrogen


Correct Option: A
Explanation:

Lactation is the method of synthesizing and secreting milk from the postpartum female breast mammary glands in reaction to a child sucking in the nipple. Mammary glands, which are enclosed in the breasts, produce the milk. The mammary gland consists of milk-carrying lactiferous ducts that grow and branch widely in reaction to estrogen, growth hormone, cortisol and prolactin during pregnancy.The prolactin of the pituitary hormone is extremely influential in establishing and maintaining the supply of breast milk. It is also essential for mobilizing breast milk maternal micro vitamins and minerals.

Foetal ejection reflex in human female is induced by?

  1. Differentiation of mammary gland

  2. Pressure exerted by amniotic fluid

  3. Release of oxytocin from pituitary

  4. Fully developed foetus and placenta


Correct Option: D
Explanation:
  • When a woman is in a lithotomy or semi-sitting position, the Foetal Ejection Reflux is impaired and the increased pain caused by the sacrum’s inability to move as the baby descends can be intolerable
  • Foetal ejection reflex in human female is induced by fully developed foetus and placenta. so, option D is correct

Gestation period of rabbit is

  1. 18 - 20 days

  2. 28 - 32 days

  3. 48 - 50 days

  4. 60 - 70 days


Correct Option: B
Explanation:

Gestation period is the time taken for embryo development after fertilization of egg in the female animal. 

In humans the gestation period is approximately 38 weeks. The gestation periods of chimpanzees (237 days), gorilla (257 days) and orangutan (260 days) indicate that the approximate nine-month gestation period predates the emergence of human beings as a species. 
The gestation periods of other animal reveals, that the length of the gestation period is largely a matter of the animal specie's size. Asian elephants have a gestation period of 645 days and African elephants 640 days. Dogs and other canines have a gestation period of about 60, which is also the period for cats. Even within the species of apes and monkeys gestation period seem to be a matter of size. For Rhesus monkeys it is 164 days and baboons 187 days. 
For small animals such as rabbits the period is about 33 days and for mice about 20 days. Thus, it appears that it takes a longer time for a big animal such an elephant to grow a baby than for a smaller animals, such as a mouse.

Monoestrous cycle animals may have

  1. One ovulation each month

  2. One egg

  3. One breeding season in a year

  4. One menses each month


Correct Option: C
Explanation:

Estrous cycle, or oestrous cycle, is the reproductive cycle found in most mammalian placental females, whereby there are recurring periods when the female is fertile and sexually receptive (estrus) interrupted by periods in which the female is not fertile and not sexually receptive (anestrus). 

Animals that have estrous cycles reabsorb the endometrium (inner membrane of the mammalian uterus) if conception does not occur during that cycle. The estrous cycle is contrasted with the menstrual cycle in which the endometrium is shed through menstruation when pregnancy does not occur and in which the female may be sexually receptive at any time during the cycle. 
There are many variations among animals in terms of their estrous cycles. Some may undergo estrous only one time a year during a particular season (monoestrous example white-tailed deer, foxes), while others may undergo a succession of cycles (polyestrous) during a certain time of the year if they do not become pregnant (horses, sheep), and others may undergo cycles throughout the whole year (mice, cows, pigs).

Gestation period is minimum in which of the following?

  1. Rabbit

  2. Man

  3. Elephant

  4. Mouse


Correct Option: D
Explanation:

Gestation period is the time taken for embryo development after fertilization of egg in the female animal. In humans the gestation period is approximately 38 weeks. 

The gestation periods of chimpanzees (237 days), gorilla (257 days) and orangutan (260 days) indicate that the approximate nine-month gestation period predates the emergence of human beings as a species. The gestation periods of other animal reveals that the length of the gestation period is largely a matter of the animal specie's size. 
Asian elephants have a gestation period of 645 days and African elephants 640 days. Dogs and other canines have a gestation period of about 60, which is also the period for cats. Even within the species of apes and monkeys gestation period seem to be a matter of size. For Rhesus monkeys it is 164 days and baboons 187 days. 

For small animals, such as rabbits the period is about 33 days and for mice about 20 days. Thus, it appears that it takes a longer time for a big animal such an elephant to grow a baby than for a smaller animal such as a mouse.

Child birth is called as

  1. Pregnancy

  2. Parturition

  3. Menstruation

  4. Menopause


Correct Option: B
Explanation:

Parturition is the process of expulsion of the child from the uterus or womb. It involves three stages- shortening and the opening of the cervix, descent and birth of the baby, and pushing out of the placenta. It is also known as childbirth. Thus the correct answer is option B.

Gestation period of rat is

  1. 20 - 22 days

  2. 28 - 32 days

  3. 52 - 65 days

  4. 60 - 65 days


Correct Option: A
Explanation:

The gestation period is the time in which the fetus develops, which starts with the fertilization and ends with the birth. The gestation period of brown rat is 21 days.
Thus, the correct answer is option (A), '20-22 days'.

Forceful muscular contraction of uterine wall is involved in.

  1. Implantation

  2. Lactation

  3. Micturition

  4. Parturition


Correct Option: D

The gestation period of elephants is about 

  1. 11 months

  2. 10 months

  3. 15 months

  4. 22 months


Correct Option: D
Explanation:
For mammals, the gestation period is the time in which a foetus develops, beginning with fertilization and ending at birth. The duration of this period varies between species.
Gestation period of an elephant (Asian) is 616 days and elephant (African) is 645 days, approx 22 months.

Assertion : Predation is an interspecific interaction with a feeding strategy.

Reason :  Predation and their prey maintain fairly stable population through time and rarely one population become abundant or scarce.


  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion

  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion

  3. If the assertion is true but the reason is false

  4. If both the assertion and reason are false

  5. If the assertion is false but reason is true


Correct Option: A
Explanation:

Predation is an interspecific interaction with a feeding strategy i.e., one species (prey) is eaten up by another (predator). The number of predator usually depends upon the population of prey, but the later is also controlled by predators. Thus, predatory and the prey maintains fairly stable population through time and rarely one population becomes abundant or scarce.

Gestation period of $280$ days is calculated from time of
  1. Last menstruation

  2. Fertilization

  3. Next menstruation

  4. Puberty


Correct Option: A
Explanation:

The gestation period is calculated from the first day of the last menstrual period. This is used to calculate the expected date of delivery (EDD).

So the correct answer is A.

Gestation period in humans is

  1. $7$ months

  2. $9$ months

  3. $25$ months

  4. $8$ months


Correct Option: B
Explanation:

Gestation period is the time period of pregnancy. It is approximately 9 months in humans. So the correct answer is B.

Gestation period is duration 
  1. Between egg growth and ovulation

  2. Between fertilization and parturition

  3. Between preparation of sex cells and fertilization

  4. None of the above


Correct Option: B
Explanation:

Development of fetus from the time of conception until birth is called as gestation period.

So the correct option is 'Between fertilization and parturition.'

Foetal ejection reflex in human female is induced by

  1. Release of oxytocin from pituitary

  2. Pressure exerted by amniotic fluid

  3. Differentiation of mammary glands

  4. Fully developed foetus and placenta


Correct Option: D
Explanation:

Parturition is an induced Complex neuroendocrine mechanism. In this signals are originated from a fully developed fetus and placenta. This lead to mild uterine contractions and hence fetal ejection reflex. Then oxytocin acts on uterine muscles leading to strong uterine contractions. This further continues to stronger and stronger contractions. As a result, the baby is expelled out of the uterus with placenta through the birth canal. 

So, the correct answer is 'fully developed fetus and placenta'

Which of the following is not the reason for very high load of bilirubin in a new born?

  1. Excessive red blood corpuscles in the new born burst, releasing bilirubin.

  2. Insoluble bilirubin in the intestine is reabsorbed by the blood.

  3. Liver of the new born is too young to cope with the heavy load of bilirubin.

  4. Mother's milk contains a high amount of bilirubin.


Correct Option: D
Explanation:

End of pregnancy leads to the initiation of the lactation period. This helps the mother in feeding the newborn. The milk produced during the initial few days of lactation is called colostrum which contains several antibodies and high content of bilirubin which protects the newborn baby.

So, the correct option is 'Mother's milk contains a high amount of bilirubin'.

Match the columns and find the correct options.

Column I Column II
a Parturition p Attachment of zygote to endometrium
b Gestation q Release of egg from Graafian follicle
c Ovulation r Delivery of baby from uterus
d Implantation s Duration between pregnancy and birth
e Conception t Formation of zygote by fusion of egg and sperm
u Stoppage of ovulation and menstruation
  1. a-q, b-s, c-p, d-t, e-r

  2. a-s, b-r, c-p, d-t, e-q

  3. a-t, b-p, c-q, d-r, e-s

  4. a-r, b-s, c-q, d-p, e-t


Correct Option: D
Explanation:

Parturition is also called as childbirth. It is the act of delivering baby from uterus. Gestation is a period of developing embryo from conception to birth. It is a duration considered between pregnancy and birth. Ovulation is a process of releasing of egg from the ovary or Graafian follicle. Implantation is the process in which fertilized egg or zygote adheres or attaches to the endometrium wall of the uterus. Conception is the act of conceiving  a baby. In this, zygote is formed from the fusion of egg and sperm.

Thus, the correct answer is 'a-r, b-s, c-q, d-p, e-t.'

Which is called milk ejection hormone?

  1. Prolactin

  2. Oxytocin

  3. Vassopressin

  4. Luteinizing hormone


Correct Option: B
Explanation:

The release of the hormone oxytocin from maternal pituitary which leads to the milk ejection.  Oxytocin stimulates the muscle contraction surrounding the breast to squeeze out the milk. 

so, the correct option is 'Oxytocin'.

Signals for parturition originate from

  1. Fully developed foetus only

  2. Placenta only

  3. Oxytocin released by maternal pituitary

  4. Both A and B


Correct Option: D
Explanation:

Parturition is an induced Complex neuroendocrine mechanism. In this signals are originated from a fully developed fetus and placenta. This lead to mild uterine contractions and hence fetal ejection reflex. Then oxytocin is released from maternal pituitary and it acts on uterine muscles leading to strong uterine contractions. This further continues to stronger and stronger contractions. As a result, the baby is expelled out of the uterus with placenta through the birth canal. 

so, the correct option is 'Both A and B'.

Which of the following statement is correct?

  1. Foetal heart is formed in second month

  2. Foetus shows movements for the first time in seventh month

  3. hPL has a major role in parturition

  4. Signal for parturition comes from fully developed foetus and placenta


Correct Option: D
Explanation:

Parturition is an induced Complex neuroendocrine mechanism. In this signals are originated from a fully developed fetus and placenta. This lead to mild uterine contractions and hence fetal ejection reflex. Then oxytocin acts on uterine muscles leading to strong uterine contractions. This further continues to stronger and stronger contractions. As a result, the baby is expelled out of the uterus with placenta through the birth canal. 

Which of the following hormones initiate parturition?

  1. ACTH, hCG, oxytocin

  2. ACTH, corticosteroid, oxytocin

  3. Corticosteroid, ACTH, prostaglandin

  4. ACTH, progesterone, hCG


Correct Option: B
Explanation:

Parturition is the process in which a mother gives birth to its young one. It initiates when the message initiating parturition starts with the fetal brain, its control of ACTH release from the pituitary, and increased cortisol production by the fetal adrenal. The cortisol stimulates placental enzymes which cause placental progesterone to be made into estrogen. Oxytocin leads to the contraction of smooth muscles of myometrium of the uterus, which directs the full term foetus towards the birth canal.

So the correct option is 'ACTH, corticosteroid, oxytocin'.

Forceful muscular contractions of uterine wall are involved in

  1. Implantation

  2. Lactation

  3. Micturition

  4. Parturition


Correct Option: D
Explanation:

Parturition or childbirth is the event of bringing a child into the world from the uterus of the mother. It is the apotheosis of pregnancy. It involves forceful muscle contractions of the uterine wall which push the child out of the womb through the vaginal canal.

So, the correct answer is 'Parturition'.

The signals for parturition originate from

  1. Placenta only

  2. Placenta as well as fully developed foetus

  3. Oxytocin released from maternal pituitary

  4. Fully developed foetus only


Correct Option: B
Explanation:

Parturition is the process of giving birth or delivery. The signals for parturition originate from the placenta as well as fully developed foetus. Both these induces uterine contractions. These uterine contractions are called as foetal ejection reflex. This then stimulates the release of oxytocin hormone from the maternal pituitary gland. 

Thus, the correct answer is 'Placenta as well as fully developed foetus.'

An animal with gestation period of more than one year is

  1. Cow

  2. Dog

  3. Camel

  4. Rat


Correct Option: A
Explanation:

  • Gestation length of a cow ranges from 279-287 days and is usually 283 days. 
  • The gestation period of a dog usually ranges from 58-68 days. 
  • The camel has a gestation period of 13-14 months or 410 days approximately. 
  • The gestation period of a rat varies from 21-23 days (rarely 26 days). 
Hence the correct answer is 'Camel'.

Short term immunity is provided by 

  1. Lysozyme

  2. Serum

  3. Vaccine

  4. Colostrum


Correct Option: D
Explanation:

Colostrum is the name given to the first milk produced by the mammary glands of mammals. It consists of various antibodies that provide natural passive immunity to the newborns. This immunity is transient and does not have a latent period or a negative phase.

So, the correct answer is 'Colostrum'.

Women who consumed thalidomide as antivomiting drug during early months of pregnancy gave birth to children with

  1. Harelip

  2. Extra fingers and toes

  3. Undeveloped limbs

  4. No spleen


Correct Option: C
Explanation:
Thalidomide is a teratogen. It is prescribed to pregnant woman to get relief from nausea during pregnancy. Teratogens are the drugs which can cause foetal abnormalities if given to a pregnant woman. These drugs can cross the placenta as it does not acts as a barrier. Thalidomide is a synthetic teratogen which causes phocomelia, a condition of undeveloped limbs (or seal like limbs) in new born babies. Sometimes, the fingers are also fused.
So, the correct answer is 'Undeveloped limbs'.

Fetal ejection reflex in human female is induced by

  1. Differentiation of mammary glands

  2. Pressure exerted by amniotic fluid

  3. Release of oxytocin from pituitary

  4. Fully developed fetus and placenta


Correct Option: D
Explanation:

Foetal ejection reflex in human female is induced by fully developed foetus and placeta which causes mild contraction. This induces the release of oxytocin from maternal posterior pituitary ultimately leading to parturation due to strong contractions.

So, the correct option is 'fully developed foetus and placenta'.

At the time of child birth, which harmone is secreted?

  1. Glucocorticoid

  2. Progesterone

  3. Relaxin

  4. Thyroxine


Correct Option: A

If both ovaries are removed from  a pregnant human female in first trimester of pregnancy then it will lead to : (Explain) the answer also)

  1. Absorption

  2. Normal development

  3. Irregular ovulation no fixed time interval

  4. Menarche


Correct Option: A

Which foetal hormone signals that it is mature now to take birth?

  1. Relaxin

  2. Oxytocin

  3. ACTH

  4. Progesterone


Correct Option: A
Explanation:

  • Relaxin is a hormone secreted by the placenta that causes the cervix to dilate and prepares the uterus for the action of oxytocin during labour.
  • Relaxin is a protein hormone of about 6000 Da.
  • Relaxin is produced by the ovary and the placenta.
So, the correct answer is 'Relaxin'

The normal gestation period in humans is 

  1. 270 days

  2. 290 days

  3. 280 days

  4. 295 days


Correct Option: C
Explanation:
Gestation period is the time period of foetal development from the day of conception until birth. The normal gestation period in humans is about 40 weeks or 280 days. This time period is calculated after the onset of woman's last period.
So, the correct answer is '280 days'.

Choose the correct answers from the alternatives given.
The period of time from conception of the zygote to delivery of the fetus is called

  1. implantation

  2. gastrulation

  3. fertilization

  4. gestation


Correct Option: D
Explanation:
 Gestation in mammals is the time between conception and birth, during which the embryo or fetus is developing in the uterus. The gestation period in humans is about 40 weeks.
So the correct option is 'gestation'.

Colostrum (mother's milk produced immediately after child birth) is beneficial for immunity of the human infant because it contains

  1. $IgF$

  2. $IgC$

  3. $IgB$

  4. $IgA$


Correct Option: D
Explanation:

Colostrum is the form of milk produced by the mother, after the birth of the baby. This is the first milk and is known to contain nutrients, proteins, antibodies and many growth factors essential for the growth and development of immunity in the baby. This milk contains high amounts of IgA. This antibody is required to protect the mucous membranes present in the throat, lungs and intestine of the baby from infection. 

Thus, the correct answer is option D. 

At the time of birth, a baby girl has thousands of immature eggs.

  1. True

  2. False


Correct Option: A
Explanation:

  • Unlike spermatogenesis, oogenesis starts in embryonic life with the formation of oogania ( gamete mother cells ).
  • Oogania starts dividing and enter into a prophase-I stage of the meiosis. They get arrested at this stage and they are called as primary oocytes now. 
  • These oocytes are basically immature eggs and they are present in thousands within each ovary of a baby.
So, the correct option is 'True'.

Mother's milk is preferred to cow's milk because it contains

  1. More fats and more lipids

  2. Less lopids and more fats

  3. More lipids and less fats

  4. Less fats and less lipids


Correct Option: D
Explanation:

Whole cow's milk also contains too much protein, sodium, potassium, phosphorus and chloride which may put a strain on an infant's immature kidneys. In addition, the proteins, fats and calcium in whole cow's milk are more difficult for an infant to digest and absorb than the ones in breast milk. So, the correct option is "D" (Less fats and less lipids).

Column I contains terms and Column II contains definitions. Match them correctly and choose the right answer.

Column I Column II
A Parturition 1. Attachment of zygote to endometrium
B. Gestation 2. Release of egg from Graafian follicle
C. Ovulation 3. Delivery of baby from uterus
D. Implantation 4. Duration between pregnancy and birth
E. Conception 5. Formation of zygote by fusion of the egg and sperm
6. Stoppage of ovulation and menstruation
  1. A - 2, B - 4, C - 1, D - 5, E - 3

  2. A - 4, B - 3, C - 1, D - 5, E - 2

  3. A - 5, B - 1, C - 2, D - 3, E - 4

  4. A - 3, B - 4, C - 2, D - 1, E - 5


Correct Option: D
Explanation:

The duration of pregnancy from conception till birth is known as gestation. It occurs for a duration of 40 weeks. The release of eggs from the ovaries (or the mature graafian follicle) is known as ovulation. Implantation is the process in which the embryo in the blastocyst stage is implanted in the uterus. When the egg fuss with the sperm resulting in the formation of zygote it is known as conception. Parturition is the act of childbirth in which the baby is delivered from the uterus. So, the correct option is 'A - 3, B - 4, C - 2, D - 1, E - 5'.

The function of oxytocin is to help in

  1. child birth

  2. growth

  3. lactation

  4. gametogenesis


Correct Option: A
Explanation:

Oxytocin i a hormone released by the posterior pituitary that helps the muscles of the uterus to contract during parturition (child birth). It also stimulates the release of prostaglandins that help cause further contraction. So, the correct option is 'child birth'.

Estrogen progesterone ratio increases during end of the 3rd trimester. This is responsible for increasing

  1. Lactation

  2. Uterine contractions

  3. Oxytocin secretion

  4. Dilation of uterus


Correct Option: A
Explanation:

  • The increased levels of oxytocin at the time of parturition are responsible for vigorous uterine contractions and the dilation of the uterus. 
  • The estrogen-progesterone ratio increases during the end of the 3rd trimester which results in the increased ability of the mammary glands for lactation.

So, the correct answer is 'lactation'.

Increase in concentration of which hormone determines the time of child birth?

  1. hCG

  2. hPL

  3. Oxytocin

  4. Progesterone


Correct Option: C

The mother gives birth to the child when the development of the _____ is complete.

  1. Utrus

  2. Zygote

  3. Foetus

  4. None of these


Correct Option: C

The act of expelling the full term foetus from the uterus is termed as

  1. Gestation

  2. Implantation

  3. Parturition

  4. Capacitation


Correct Option: C
Explanation:

The process of delivery of foetus is called as parturition. Parturition is the act of expelling the full-term foetus from the mother's uterus at the end of gestation. In this process fully developed foetus produces foetal ejection reflex which stimulates pituitary to release oxytocin hormone. This hormone causes vigorous uterine contraction that leads to the delivery of feotus. This process is also known as the delivery of the foetus when the pregnancy period gets over. The importance of parturition is that the event results in the foetus to come out of the womb. The process is accompanied with the onset of lactation.

Thus, the correct answer is option C. 

Gestation period of Salamandra atra is 

  1. 200 days

  2. 540 days

  3. 36 months

  4. 440 days


Correct Option: C
Explanation:

Salmonella atra is an amphibian having one of the longest gestation periods among animals existing on this earth. They have a gestation period between 36-48 weeks.

They are unique in the sense that it has an ovo-viviparous method of reproduction by which it gives birth on land to fully metamorphosed offspring causing such a long gestation period.
So, the correct option is '36 months'.

Which grouping has gestation period in decreasing order?

  1. Cow, Horse, Goat, Monkey and Swine/ Pig

  2. Horse, Cow, Goat, Monkey and Swine

  3. Money, Cow, Horse, Goat and Swine

  4. Monkey, Horse, Goat, Cow and Swine


Correct Option: B
Explanation:

The horse has a gestation period of around 342 days whereas it is around 289 days for the cow.

Goat has a gestation period of 165 days and for Monkey, it is 155 to 160 days. Pig has the least gestation period of around 116 days.
So, the correct option is  'Horse, Cow, Goat, Monkey, and Swine'

Oxytocin is helpful in

  1. Semen formation

  2. Parturition

  3. Diuresis

  4. Molecular development


Correct Option: B
Explanation:

Oxytocin is a hormone which is released from the pituitary gland. It is responsible for the muscular contraction which occurs during the parturition. The fully developed baby exerts a pressure on the walls of the uterus and as a result, it signals the pituitary gland to release oxytocin. The muscular contractions are responsible for the expulsion of the baby out of the uterus.

So, the correct option is 'Parturition'.

Which of the following relates to the term "after-birth"?

  1. Amniotic fluid passing out

  2. Expulsion of baby

  3. Expulsion of placenta, umbilical cord and foetal membrane

  4. Secretion of hormone relaxin


Correct Option: C
Explanation:

Parturition or childbirth is the event of bringing a child into the world from the uterus of the mother. It involves forceful muscle contractions of the uterine wall which push the child out of the womb through the vaginal canal. Several events take place after the birth of the child, including expulsion of the placenta, umbilical cord, and fetal membrane.

So, the correct answer is 'Expulsion of the placenta, umbilical cord, and fetal membrane'.

Foetal ejection reflex in human female induces

  1. Release of hormones from placenta

  2. Growth and development of ovarian follicles

  3. Release of oxytocin from maternal pituitary

  4. Release of gonadotrophins

  5. Release of prolactin from pituitary


Correct Option: C
Explanation:

Foetal ejection reflex occurs at the time of parturition and are gentle uterine contactions produced by the placenta. This may occur due to extremely high levels of adrenaline during childbirth. Since parturition is a neuro-endocrine process, oxytocin is released by the neurohypophysis of maternal pituitary which stimulates stronger contractions of the uterus and induces labour pain, with decreasing progesterone levels and marks the end of the gestation period. Hence, the correct answer is 'Release of oxytocin from maternal pituitary'.

Choose the correct answers from the alternatives given.
Which of the germ layers is best associated with development Of the heart?

  1. Ectoderm

  2. Mesoderm

  3. Endoderm

  4. All of these


Correct Option: B
Explanation:

The ectoderm, which is made up of columnar cells, forms the epidermis of the skin, nervous system, cornea, lens, retina, salivary glands and the enamel of teeth. The mesoderm gives rise to the dermis of skin, gonads, heart, blood and lymph, kidney, reproductive ducts and most of the muscles. The last layer, the endoderm gives rise to the gastric and intestinal glands, liver, pancreas, lining of the middle ear.

So the correct option is 'Mesoderm'.

The fluid released from the vagina lust prior to childbirth is

  1. Baby's accumulated urine

  2. Amniotic fluid

  3. Mothers plasma from the umbilical cord

  4. Baby's plasma from its fetal circulation


Correct Option: B
Explanation:

The amniotic fluid is the protective liquid contained by the amniotic sac of a gravid amniote. This fluid serves as a cushion for the growing fetus but also serves to facilitate the exchange of nutrients, water, and biochemical products between mother and fetus. Amniotic fluid is present from the formation of the gestational sac. The forewaters are released when the amnion ruptures prior to childbirth.

So the correct option is 'amniotic fluid'.

During parturition which joint allows smooth movement of the foetus?

  1. Amphiarthrosis

  2. Syndesmoses

  3. Pubicsmphysis

  4. Gomphosis


Correct Option: A
Explanation:

During pregnancy in the human, hormones such as relaxin allows the pelvic bones to be more flexible for delivery. The gap of the symphysis pubis, normally is 4–5 mm but during pregnancy there is an increase by at least 2–3 mm. The symphysis pubis separates to some degree during childbirth hence pubic symphysis is an amphiarthrodial joint.

So, the correct option is 'Amphiarthrosis'.

Milk secretion is caused by :-

  1. Progesterone

  2. PRH

  3. PRL

  4. Oxytocin


Correct Option: D
Explanation:

Oxytocin is a peptide hormone secreted by the posterior pituitary. It is also a neuropeptide, used for inter-neuron communication. This hormone is responsible for secretion or ejection of milk. PRH or prolactin releasing hormone is responsible for the release of Prolactin or PRL, which is a hormone responsible for milk production. Progesterone inhibits lactation during pregnancy.

So, the correct option is 'Oxytocin'.

What is "After birth" referred to?

  1. Amniotic fluid passing out

  2. Expulsion of baby

  3. Expulsion of placenta, umbilical cord and foetal membrane

  4. Secretion of hormone relaxin


Correct Option: C
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