Why are the leaves in the cactus plant modified to form spines?

Ricardo notices that when he plays soccer in the rain, his ball does not seem to go as far after a kick. what is the best scientific question that ricardo could ask about this observation? is soccer better played in the rain or sun? how does rain affect the distance a soccer ball can travel? how does rain affect the speed of a soccer ball? is soccer affected by the rain?

The distant ancestors of tigers may have had bodies without stripes. use the theory of natural selection to explain how tigers may have evolved to have stripes.

Acell goes through cellular respiration and produces atp which it then uses to move a molecule across the cell membrane. how does the energy in the original glucose molecule change during this process? (2 points)