B) They supply the body’s cells with oxygen
Answer:
Infectious diseases are caused by pathogens, which include bacteria, fungi, protozoa, worms, viruses, and even infectious proteins called prions. Pathogens of all classes must have mechanisms for entering their host and for evading immediate destruction by the host immune system. Most bacteria are not pathogenic.
Explanation:
The answer is hox gene.
Hox genes are responsible for an embryo's body plan. They determine different body structures - legs, vertebrae, antennae, wings, depending on groups. Mutation in hox genes is serious mutation since it affects the early stages of embryo and consequently, normal development. If a mutation occurs in the hox gene for legs growth, the legs will not develop.
<span>maintains a constant INTERNAL environment
so other options included internal variable and external environment. but its internal and environment</span>
