Question

Recognize the figure and find out the correct matching.

• A. (A) a-morula, b-blastocyst
• B. (B) a-blastocyst, b-morula
• C. (C) a-blastocyst, b-gastrula
• D. (D) a-morula, b-gastrula

Answer 1

Answer: (A)

(A) a-morula, b-blastocyst

Answer 2

Explanation:
Fertilization results in the formation of a zygote that takes place in the oviduct. This zygote then undergoes a series of changes before it actually gets implanted in the uterus. Zygote first undergoes cleavage and results in the formation of 16 cells known as a morula. This is a solid ball and is represented by figure a. The morula then enters the uterus and undergoes changes. The 16 celled morula further forms 32 cells and these then start arranging in two layers: outer trophoblast and inner embryonal mass. This also forms a cavity and is known as a blastocyst and the structure is known as a blastula. This now gets implanted in the uterus. Thus figure b is a blastocyst. Hence, the correct option is (A).