Question

Choose the correct answers from the alternatives given.
Primary tissue layers first appear

• A. in the egg cortex
• B. in the gastrula
• C. during cleavage
• D. in primary organs

Answer 1

The correct option is B in the gastrula

The germ layers develop early in embryonic life, through the process of gastrulation. During gastrulation, a hollow cluster of cells called a blastula reorganises into two primary germ layers, an inner layer, called endoderm, and an outer layer, called ectoderm.

So the correct option is ' in the gastrula '.