Give three important distinguishing characters of arthropods, reptiles and mammals.
Three important distinguishing characters of arthropods, reptiles and mammals are: (i) Arthropods: - Arthropods have jointed appendages, segmented bodies divided into the head, thorax, and abdomen, a hard non-living chitinous exoskeleton, and compound eyes. Example: - Insects, centipedes, etc. (ii) Reptiles: - They are cold-blooded, the body is covered by scales, possess two pairs of limbs and lay eggs. Example: - Lizard, snake etc. (iii) Mammals: They are warm-blooded, have a hairy body, an external ear, give birth to young, have small pointed teeth, and a long snout. Example: - Dog, monkey, lion etc.
