1. Japanese gardeners regularly trim away parts of the root
system to assist in dwarfing a plant. A plant’s food is
obtained through photosynthesis in the leaves; can you
suggest why trimming the roots can cause dwarfing?
2. It was suggested that roots perceive gravity through the
root cap. Would it really matter if roots grew randomly
in the soil instead of responding to gravity?
3. From the viewpoint of the plant, can you suggest a
practical reason for branch roots originating internally
instead of at the surface?
4. When you eat a yam or a sweet potato, what kinds of
compounds and cells are you consuming?
5. Persons associated with commercial nurseries and
greenhouses often sterilize their soil by heating it to get
rid of pests, but then they have to wait for a short time
after it has cooled to use it. Why?

1. Trimming the roots could cause dwarfing because nutrients are obtained through the roots, which aid in growing the plant.

2. Yes! You wouldn't want roots going upwards towards the stem, or in whatever direction they pleased. That they go downward assists the stability of the plant (like it not falling over).

3. So that they don't break off from the soil. They wouldn't anchor the plant if they were at the surface only.

4. Yams and sweet potatoes contain starch, which is a carbohydrate derivative of glucose.

5. They need to moderate the amount of heat they apply. The plants won't grow well in the heated soil because the organic matter in soil that helps plant growth isn't present. Although sterilization can kill bacteria and small animals like nematode worms, it should be done in moderation.

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.