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.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.