The heart and arteries are key structures in which system?
a.
digestive system
b.
nervous system
c.
respiratory system
d.
circulatory system

Flock x flock y flock z total pieces of food eaten (from previous page) 147 93 60 food percentage* % % % simulated number of birds in flock for 3rd generation** * divide each flock's total pieces of food by 300, the total number of pieces of food eaten. ** multiply the food percentage for each flock by the total number of birds (30).

What environmental cues and landmarks do the geese use to determine the timing and direction of their migration over the mountains? how do they find their way?

Which macromolecule catalyzes chemical reactions this be considered enzyme chemical reactions thus he considering enzymes