"does stress during a woman's first trimester of a pregnancy affect the infant's birth weight? " is a

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.

How can you keep track of variables in a science experiment?

Penelope studies how the structure and function of the nervous system is related to behavior. she is a psychologist