When white blood cells encounter an infection in the body, they create chemicals and enzymes that activate receptor sites on the that then signal the brain that the body is sick?

Which best explains why viruses do not have special structures or enzymes that allow them to make their own food? viruses can use energy in living cells that they infect. viruses can replicate inside a host that they infect. viruses can cause contagious illnesses in host cells. viruses integrate their rna or dna into infected cells.

In this experiment, the was intentionally manipulated. it is the independent variable. the dependent variables that were measured were the

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.