Question

An egg of bird was coated with varnish and then incubated. The egg did not hatch because the developing embryo:

• A. Could not utilise the yolk in the presence of excess amount of nitrogenous wastes
• B. Died because of toxic effect of varnish
• C. Could not excrete and died
• D. Died because of depleted oxygen availability

Answer 1

The correct option is D

Died because of depleted oxygen availability

The correct option is D:

Explanation of the correct option:

1. The eggs of birds are oviparous animals that are rich in yolk and help the full development of the embryo.
2. Even though the fertilization is internal, there is a gaseous exchange with the environment once the egg is laid.
3. Hence the oxygen exchange is depleted when varnish or paint is coated on the egg where an embryo cannot be developed.

Explanation of the incorrect option:

Option A:

1. The egg of birds is rich in yolk and helps full development of the embryo
2. However, eggs have a porous calcium-rich shell surrounded.
3. The fertilization is internal.

Option B:

The developing embryo died not because of the toxicity of varnish.

Option C:

The egg does not excrete.

Final answer: An egg of a bird was coated with varnish and then incubated. The egg did not hatch because the developing embryo died because of depleted oxygen availability