मानव भ्रूणीय विकास के दौरान निम्नलिखित में से कौन सा अंग सबसे पहले बनता है और कार्यात्मक होता है?

The embryo begins to differentiate itself into three distinct layers known as:

The protective fluid that surrounds and cushions the developing embryo inside the gestational sac is called:

A nurse educating postgraduate nursing students explains early embryonic development. Which finding best confirms that an embryo has progressed beyond the morula stage but has not yet implanted?