Step 1: Understanding reptilian eggs.
Reptiles are amniotes that lay shelled eggs adapted for terrestrial reproduction. Their eggs show special adaptations to prevent water loss and support embryo development outside water.
Step 2: Meaning of cleidoic egg.
A cleidoic egg is a closed, shelled egg that prevents dehydration. It allows development of the embryo in a self-contained aquatic environment within the shell.
Step 3: Amniotic nature.
Reptilian eggs are amniotic because they possess extra-embryonic membranes like amnion, chorion, and allantois. These membranes protect and nourish the developing embryo.
Step 4: Yolk content (megalecithal).
Reptilian eggs contain a large amount of yolk, making them megalecithal. This yolk provides nutrition for the developing embryo throughout development.
Step 5: Evaluation of options.
Other options are incorrect because reptiles do not have microlecithal, centrolecithal, or alecithal eggs. Their eggs are always yolk-rich and amniotic.
Step 6: Final conclusion.
Thus, reptilian eggs are cleidoic, amniotic, and megalecithal.