How does the blastocyst ensure its own survival in the uterus ?

(a) What do you understand by the term 'variation' ? (b) Name two human traits which show variation . (c) How does the creation of variation in a species ensure its survival ?

Fixing up of the blastocyst in the wall of the uterus is known as:

The implantation process involves the following steps : (I) The morula continues to divide and transforms into blastocyst as it moves further into the uterus. (II) The uterine cells divide rapidly and the blastocyst gets covered by them. (III) Morula is formed. (IV)As the zygote moves through the isthmus of the oviduct towards the uterus, it undergoes mitotic division and forms 2, 4, 8, 16 daughter cells called blastomeres. Choose the correct sequence:

During Implantation, the blastocyst beco,es embedded in which layer of the uterus?