Question

Vascular and excretory organs are formed from

• A. Endoderm
• B. Mesoderm
• C. Ectoderm
• D. None of the above

Answer 1

The correct option is B Mesoderm

The inner cell mass of the blastocyst after implantation differentiates into an outer ectoderm, middle mesoderm and inner endoderm. These layers then develop into tissues and organs of the embryo. Endoderm gives rise to certain organs including the colon, stomach, intestines, liver, lungs and pancreas. Mesoderm gives rise to heart, kidneys, gonads, genital ducts, cartilage, muscles, blood cells, and other structures. Ectoderm forms the outer linings like the epithelium, brain, spinal cord, nerves, ears, nails and hair.

The vascular organs include the heart and related organs and excretory organs include the kidney, bladder etc.

So the correct answer is B.