This set of Biology Multiple Choice Questions & Answers (MCQs) focuses on “Human Reproduction – Parturition and Lactation”.
1. The average duration of the gestation for humans is 9 months.
Explanation: The period from conception to birth of a viviparous organism is its gestation period. It varies for different organisms. It is 40 weeks approximately or 9 months for humans.
2. The act of delivering a fetus at the end of pregnancy is called ________
Explanation: Parturition, also known as childbirth, is the process in which vigorous contraction of the uterus is induced, leading to the expulsion of a fetus. It includes preparation of myometrium and cervix during pregnancy, uterine preparation, uterine contraction, and involution.
3. Vigorous contractions of the uterus during parturition are induced by ________
a) neuroendocrine mechanism
b) endocrine mechanism
c) embryo pushing out
d) uterine fluids
Explanation: Two major processes induce the contractions of the uterine wall during parturition. The hormones secreted from the pituitary and placenta alongside the reflexes induced by the oxytocin function to stimulate the muscle continuously. Thus this is a neuroendocrine process.
4. What is the correct sequence for parturition to occur?
a) Signal from fetus and placenta → Uterine contractions → Release of oxytocin → Rise in oxytocin secretion → Powerful contractions → Parturition
b) Uterine contractions → Release of oxytocin → Rise in oxytocin secretion → Powerful contractions → Signal from fetus and placenta → Parturition
c) Signal from fetus and placenta → Release of oxytocin → Uterine contractions → Rise in oxytocin secretion → Powerful contractions → Parturition
d) Release of oxytocin → Uterine contractions → Signal from fetus and placenta → Rise in oxytocin secretion → Powerful contractions → Parturition
Explanation: Parturition starts with the signal released by the fetus and the placenta. These act on the pituitary to release oxytocin. Oxytocin acts as a stimulant leading to contractions of the uterine muscles. The uterine contractions feedbacks to release more oxytocin from the pituitary. This results in more powerful contractions of the uterus until the baby is delivered in the process of parturition.
5. What is injected to induce delivery in humans?
Explanation: Oxytocin is the stimulant released from anterior pituitary to increase contractions of the uterine wall. Decreased levels of oxytocin can result in the inability to push the baby out. In such scenarios, the patient is injected with intravenous oxytocin to induce uterine contractions to deliver the baby.
6. Production of milk by mammary glands of female towards the end of pregnancy is called _________
Explanation: Mammary gland cells develop the potential to produce milk towards the end of pregnancy. This process is termed as lactation.
7. What is the milk produced in the initial few days of lactation called?
a) Corpus luteum
c) Corpus albicans
Explanation: The first couple of days after the onset of lactation, the milk produced from the mammary glands is yellowish and rich in nutrients and antibodies for the newborn baby. This is called colostrum.
8. What is colostrum rich in?
d) Life fluid
Explanation: The colostrum is produced by the mammary glands for the first few days after the baby is born. The purpose is to protect the baby from the antigens it will be exposed after entering the world for the first time. Hence it is enriched with antibodies.
9. Antibodies in colostrum provide new-borns with__________
b) long life
d) tall height
Explanation: The antibodies in the colostrum help the body of the baby, which has been exposed to the external world full of different antigens, the ability to fight. This is called immunity.
10. What is the period of pregnancy called?
b) Menstrual cycle
Explanation: The time taken by a developing embryo inside the womb of a placental mammal is called the gestation period, at the end of which a baby is delivered in the act of parturition.
11. What is the reflex that leads to the expulsion of baby called?
a) Feet withdrawal reflex
b) Knee jerk reflex
c) Fetal ejection reflex
d) Oxytocin reflex
Explanation: Parturition is initiated by the fetus and the placenta. Leading to oxytocin signaling and uterine contractions. This reflex is called fetal ejection reflex.
Sanfoundry Global Education & Learning Series – Biology – Class 12.
To practice all areas of Biology, here is complete set of 1000+ Multiple Choice Questions and Answers.
Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!