How would an asthma attack affect oxygen delivery in the body

Which statement is true about the cell theory? a) it is well-supported by evidence. b) it is unchangeable and permanent.

The nervous system interacts with the endocrine system by a. using hormones as connections b. sending nerve impulses directly to glands c. using neuroendocrine cells as connections d. sending neurotransmitters directly to neurons

What is used as a template during replication? a- mrna b- trna c- rrna d- dna