Questions: Reptilian embryos will not dry out in a desert habitat because reptiles' eggs are protected by a jellylike coating reptiles produce lots of defensive slime the placenta facilitates exchanges between the mother and the embryo reptiles produce shelled amniote eggs

The answer is the fourth one (or D): reptiles produce shelled amniote eggs.

Explanation for each option:

1. Reptiles' eggs are protected by a jellylike coating: This is incorrect. Jellylike coatings are characteristic of amphibian eggs, not reptilian eggs. Amphibian eggs are typically laid in water and have a gelatinous covering, which would not prevent desiccation in a desert environment.

2. Reptiles produce lots of defensive slime: This is incorrect. Reptiles do not produce defensive slime. This characteristic is more commonly associated with certain amphibians and fish.

3. The placenta facilitates exchanges between the mother and the embryo: This is incorrect. While placental exchange is a feature of mammals, reptiles do not have a placenta. Reptilian embryos develop within eggs, not within the mother's body.

4. Reptiles produce shelled amniote eggs: This is correct. Reptiles lay amniote eggs, which have a protective shell and several membranes that prevent desiccation and provide a stable environment for the developing embryo. This adaptation allows reptilian embryos to survive in dry, terrestrial habitats, including deserts.

Summary: Reptilian embryos will not dry out in a desert habitat because reptiles produce shelled amniote eggs.