Which of the following is the best example of structural adaptations? dropping leaves for plants, quills for porcupines
leaf type for plants, quills for porcupines
leaf type for plants, learning to ride a bicycle for humans
dropping leaves for plants, migration for sea turtles
HELP

Astudent wants to test the hypothesis that fertilizer improves the growth rate of grass seeds. to test this hypothesis, the student put the same amount of grass seed in 3 containers with the same type of soil. the student measured the growth at the end of the week. all plants received equal amounts of water and sunlight. if you were asked to graph this data, what would you place on the x-axis? a. fertilizer b. water c. plant growth d. week one