FERTILISATION AND IMPLANTATION Flashcards
(22 cards)
Release of semen into the vagina by the penis is called _____________
Insemination
The motile sperms swim rapidly and go through what path ?
Cervix –> Uterus –> Ampullary region of fallopian tube
Ovum released by ovary does not transport and stays at its original location.
True/false
False
Transported to ampullary region
Fertilisation takes place in the ______________
ampullary region
Why do all copulations not lead to fertilisation and pregnancy?
Ovum and sperms have to be transported simultaneously to ampulla for fertilisation.
Process of fusion of a sperm with an ovum is called _____________
Fertilisation
During fertilisation, sperm comes in contact with the ____________ of the ovum and induces changes in the ________ that helps in __________.
Zona pellucida layer, membrane , blocking entry of additional sperms to ensure that only one sperm can fertilise an ovum.
The secretions of ________ help the sperm to enter the cytoplasm of the ovum through the ____________ and the __________
Acrosome, zona pellucida, plasma membrane
The entry of sperm induces ____________
completion of meiosis of secondary oocyte
The 2nd meiotic division is equal and results in formation of 2 polar bodies.
True/false
False
Unequal, 2nd polar body and haploid ovum(ootid) formed
Sex of the baby is decided at which stage?
When the haploid nucleus of sperm and that of ovum fuse to form diploid zygote.
75 % of sperms carry the X sex chromosome and 25% carry the Y.
True/false
False
50-50
The zygote carrying ________ develops into female while that carrying ________ develops into male
XX sex chromosomes, XY sex chromosomes
Scientifically, it is correct to say that the sex of baby is determined by mother.
True/false
False
The mitotic division starts as the zygote moves through the ____________ of the oviduct towards the uterus and the process is called _________.
Isthmus, Cleavage
Cleavage in the zygote forms daughter cells called ___________
Blastomeres
Embryo with ________ (no.) blastomers is called Morula.
8-16
As the morula moves further into the ________, it transforms into ____________
Uterus, blastocyst
How are the blastomeres arranged in blastocyst?
Outer layer - trophoblast
Inner group of cells attached to trophoblast - inner cell mass
Functions of inner and outer layer of blastocyst?
Trophoblast attached to endometrium
Inner cell mass gets differentiated as embryo
After attachment, ________ cells divide rapidly and covers __________
Uterine, blastocyst
Blastocyst becomes embedded in myometrium of uterus and the process is called gestation that leads to pregnancy.
True/false
False
endometrium, implantation
