When a person eats, the brain signals the stomach to start breaking down the food. Which two 1 point systems are involved in this process?*
Circulatory and respiratory
Nervous and digestive
Digestive and excretory
Muscular and digestive

Can you identify which of the following groups of organisms are, or are not, populations? a. the american bison (bison bison) and grey wolves (canis lupus) currently living in yellowstone national parkb. all of the rainbow trout (oncorhynchus mykiss that) that have ever lived in lake eriec. the group of american bison (bison bison) currently living in yellowstone national parkd. a group of calliope hummingbirds (selasphorus calliope) and a group of rufous hummingbirds (selasphorus rufus) living in the same new hampshire woodse. the northern cardinals (cardinalis cardinalis) living on opposite shores of lake champlain f. all of the whales currently living in the atlantic ocean off cape cod, massachusetts

In the water cycle , when does water undergo a chemical change

Iwill make you brainliest pleeze answer this fast i have to turn it in really soon brainliest promise easy question 6th grade ! a weather map shows a high pressure system with circles around it. what does this mean? a) an occluded front b) areas of equal altitude c) areas of equal pressure d) a stationary front