Abiologist discovered a young, four-legged animal. the animal had lungs, seemed to fertilize internally, and its outer surface was covered with scales. in which class of animals is the biologist likely to place the animal? a. fish b. mammals c. amphibian d. reptile

The correct answer is option D. Reptiles

Explanation:

The group of animals with four legs, having lungs, fertilize internally and the outer surface is covered with scales are classified as reptiles and such animals should be placed in class reptiles. Reptiles generally have tetrapods or four-legged except few such as snakes, most of the reptiles fertilize internally and also have scales on the outer surface such as snakes.

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.