Pregnancy And Embryonic Development:Human Reproduction NCERT In Hindi&English

pregnancy,embryonic developments,

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Hello students,In this section,we are going to look NCERT important topic Pregnancy and Embryonic development of Human Reproduction. First took a NCERT paragraph or sentence then It was explained in simple english words and Hindi too.

Main contents of this article

|| Pregnancy ||Essential Hormones ||Embryonic Development during pregnancy ||MCQ Pregnancy and Embryonic Development || Answer Sheet ||


The fertilized ovum (embryo) travels down into the uterus this process is called Implantation and It leads to pregnancy then and embryonic development.

NOTE: To better understand to this topic I recommended have a glance Gametogenesis

Explanation of above paragraph

Implantation: when an embryo attached to the uterus wall,

After Implantation pregnancy stage starts

Implantation:Jab embryo uterus se jodta hai es parkirya ko Implantation kahte hai

Implantation kay bad pregnancy ka awasth aata hai

The embryo travels toward to uteru, after implantation, finger -like projections appear on the trophoblast known as “chorionicvill,” The chorionic vill  are surrounding surrounded by the uterine tissue and maternal blood.

Explanation of above paragraph


Trophoblast:Just after four days of fertilization, the ouster layer of blastomere parents of some cells

Chorionicvill: Some fingers like stracture appears on trophoblast.


Fertilization kay 4 days baad blasto- meres kay bahari hisse par kuch c- ells present hota hai jise Trophobla-st khate hai

Kuch fingers like stracture trophob-last par nazar aata hai jiise Chorionicvill kahte hai aur mother blood aur uterus kai wall ghere rahta hai


The chorionic villi and the uterine tissue (tissue of uterus) become interdigitated with each other and jointly from a structural and functional unit between developing embryo (foetus) and mother (maternal)body called placenta. However, Important function of placenta that is facilitate the supply of oxygen and supply of nutrients to the embryo. And It also removal of carbon dioxide and excretory/waste maternals produced by the embryo.

Explanation of above paragraph


  • Placenta:The chorionic villi and uterine tissue interlock like fingers of two clasped hands
  • Placenta is an organ that provide all facilities to growing foetus.
  • The chorionic vill and uterine tissue became interdigitated
  • Placenta works structral and functional unit between developing fetal and maternal body.
  • Supply Oxygen and Nutrients to the embryo it very important function of placenta
  • Removal of carbon dioxide and waste materials products which is produced by embryo



  • Chorionic villi aur uterine tissue apas mai yese mile hote hai jaise dono hatho kai fingers ko aapas fasate hai
  • Placenta ak organ hai jo garv ma baby ki development mai har trah ki Suvidha deta hai
  • Chorionic vill Aur uterine tissues interdigit Hote Hain
  • Maternal body aur developing foetus ke liye Placenta stractural and functional work karta hai
  • Yah embryo ko Oxygen aur Nutrients supply karta hai jo bhut important function hai
  • Carbon dioxide and waste materials ko remove karta hai jo embryo ke dwara utpad H-ota Hai

The placenta  connects to the embryo through an umbilical cord which helps in the transport of substances to and from the embryo.

Explanation of above paragraph



  • BY umbilical cord connects to the embryo and helps in transport of substance to the embryo and also from the embryo


  • Placenta, Embryo se umbilic-al cord ke dwara judta hai hi or ah umbilical cord transpo-rt ka Karya karta hai matern-al body se embryo or embryo se maternal body tak

Essential hormones

Hormones those are essential and required for pregnancy and embryonic development.The placenta also acts as an endocrine tissue and produces several hormones like human chorionic gonadotropin (hCG), human placental lactogen (hPL), estrogens, progestogens, etc. In the later phase of pregnancy, a special hormone called relaxin is also secrete by the  ovary.

And, must remember that hCG, hPL and relaxin produces in women only during pregnancy.  

Explanation of above paragraph


  • The placenta works as like an endocrine tissues
  • It produces hormones like human chorionic gonadotropin (hCG), human placental lactogen hPL estrogen, progestogens
  • Later phase of pregnancy a hormone is relaxin secrete by ovary



  • Palacenta endocrine tissue ke Tara-h Karya karta hai
  • Yah hormone ka utpad karta hai Jaise a human chorionic gonadotropin (hCG), human placental lactogen (hPL estrogen, progestogens
  • Pregnancy ke bad wale page mein Ek hormone Relaxin Jo ovary se a secret Hota Hai


In addition, during pregnancy and embryonic development  the levels of other hormonès like estrogens, progestogens, cortisol, prolactin, thyroxine, etc. increases several folds in the maternal blood. Increased production of these hormones is necessary for supporting the fetat growth, metabolic changes in the mother and maintenance of pregnancy. 

Explanation of above paragraph


  • Hormones like estrogens pro-gestogens, coristol, prolactine, thyroxine increases several folds in maternal body during pregnancy and embryonic development
  • These hormones is essential for fetal growth, metabolic changes in the mother and maintenance of pregnancy.


  • Hormone estrogen, progest-ogens, coristol,prolactine, thyroxine etc pregnancy and embryonic development kai duran bahut Sare maternal blood Folds ka increase karta hai
  • Yeah hormone fetal growth, mother mai metabolic change, aur pregnancy maintenance ke liye bahut Jaruri Hota Hai

Immediately after implantation, the inner cell mass (embryo) differentiates into two important layers, an outer layer called ectoderm and an inner layer called endoderm

However a mesoderm soon appears between the ectoderm and the endoderm. These’ three layers give rise to all tissues (organs) in adults.  It needs to be mentioned here that the inner cell mass contains certain significant cells called stem cells which have the strength to give rise to all the tissues and organs

Explanation of above paragraph


  • Soon after implantation the embryo differentiates into two important layer inside endoderm outside ectoderm then after a middle layer called mesoderm.
  • Thses three layers are respon-sible for all tissues and organs formation.
  • Stem cells: which have poten-tials to give rise to all tissue and organs.



  • Implantation ke turant bad embryo two importance layer Mein differentiated Hota Hai, Andar side wali layer ko endoderm aur bar side layer ko ectoderm Kaha Jata Hai Iske alawa middle wali layer ko mesoderm Kahate Hain
  • Yah teeno layers Sabhi tissue or organs ke formation ke liye responsible hai
  • Stem cell Jo Sabhi organs aur tissues ke formation ke liye capable hota hai

Embryonic development during pregnancy:


The human pregnancy lasts 9 months. In human beings after one month of pregnancy, the empbryo’s heart is formed.  The first sign of growing fetal may be noticed by listening to the heart sound carefully through the stethoscope instrument.  By the end of the second month of pregnancy, the foetus well develops limbs and digits. 

By the end of 12 weeks (first trimester), most of the major organ systems (like heart,kidney liver etc) are formed, for example, the limbs and external genital organs are well developed.

Explanation of above paragraph


  • After one month of pregnancy heart makes
  • By the stethoscope heart sound listening
  • Second month end,limbs and digits developed.
  • End of 12 week organs like heart, kidney, lung etc are developed.


  • One month pregnancy mai heart banjata hai
  • Stethoscope se heart beats sound suna ja sakta hai
  • Second months kai end mai limbs and digits ka vikash hota hai
  • End of 12 week organs like heart, kidney, lungs ets ka vikash hojata hai

And by the end of about 24 weeks (end of second trimester), the body is covered with fine hair. eye-lids separate, and eyelashes are formed. At last, by the end of nine months of pregnancy, the foetus is fully developed and is ready for delivery.

Explanation of above paragraph


  • End of 24 weeks body with fine hair, eye-lids separate and eyelashes are formed


  • After 24weeks, body mai fine hair,eye-lids ka alag hona aur eyelashes ka development hone lagta hai

MCQ Pregnancy And Embryonic development

1 The signals for parturition originate from

(a) Pressure exerted by amniotic fluid

(c)Fully developed foetus and placenta

(b) Release of oxytocin from pituitary

(d)Differention of mammary glands

2 The layer of uterus which becomes much eroded due to present placental villi is known as

(c) Endothelium

(d) Endoderm

(b) Endometrium

(d) Trophoblast

3 which of the following hormones is not secreted by human placenta

(a) hCG




4 match the following and choose the correct option

Column 1

A trophoblast

B cleavage

C Inner cell mass

D Inner cell mass

Column 2

1 embedding of blastocyst site in the endometrium

2 Group of cell that would differentiate and form as embryo

3 Outer layer of blastocyst attached to the endometrium

4 Mitotic division of zygote


(a) A-2 B-1 C-3 D-4

(b) A-3 B-4 C-2 D-1

(c) A-3 B-1 C-2 D-4

(d) A-2 B-4 C-3 D-1

5 Identify the correct statement from the following options

(a) High levels of estrogen triggers the voluntary surge

(b) Oogonial cell start to proliferate and give rise to functional ovum in regular cycles from poverty onword.

(c) Sperm released from seminiferous tubules are highly motile

(d) Progesterone level is high during the post of ovulatory phase of menstrual cycle

6 Which layer develops first during embryonic development

(a) Ectoderm

(b) Endoderm

(c) Mesoderm

(d) Both a&b

7 The process by which ova format is known as



(b) Ovulation

(d) Oviparity

8 Which is immortal

(a) Plasma cell

(b)Brain cell

(b) Germ cell

(d)Kidney cell

9 Which one of the following is not the function of placenta

(a) Secretes Oxytocin during parturition

(b) Facilitates supply of Oxygen and nutrients to embryo

(c) Secrets estrogen

(d) Facilitates remove of carbon dioxide and waste material from embryo

10 Several hormones like hCG, hPL, estrogen, progesterone are produced by


(c)Corpus luteum

(b) Amonion

(d) Placenta

11 The process of delivery of the foetus is called


(c) Fertilization


(d) Lactation


1 c 2 b 3d 4 b 5d 6 c 7a 8 b 9a 10d 11a

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