Which process normally occurs at the placenta? (1) Oxygen diffuses from fetal blood to maternal
blood.
(2) Materials are exchanged between fetal and
maternal blood.
(3) Maternal blood is converted into fetal blood.
(4) Digestive enzymes pass from maternal blood
to fetal blood.

Did you know that a single bee would have to go to over 2 million flowers to make a single pound of honey?

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

Adaptive radiations can be a direct consequence of four of the following five factors. selectthe exception. a) vacant ecological niches b) genetic drift c) colonization of an isolated region that contains suitable habitat and few competitor species d) evolutionary innovation e) an adaptive radiation in a group of organisms (such as plants) that another group uses as food