Label or a placard colored black and white with a skull and crossbones falls under which class

The correct answer is class-6 toxic and infectious components.

Explanation:

A placard or a label colored black and white with a skull and crossbones comes under class-6 health hazards. The class-6 is further sub differential into two categories, that is, class 6.1 and class 6.2.  

Class 6.1 signifies toxic substances, which possess the tendencies to cause serious injury or death or harm human health is inhaled or swallowed or coming in contact with skin.  

Class 6.2 comprises infectious substances, which are anticipated to constitute pathogens. The pathogens are illustrated as microbes that can result in diseases in animals or humans.  

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.

protist eukaryotes that are not plants, animals, or fungi ("misfits")