plzzzzzzzz answer quick.

Asked by khushal305 | 28th May, 2009, 07:31: PM

Expert Answer:

The valves in heart prevent the backflow of blood and maintains the blood flow in only one direction.

 

Growth in plants takes place with the help of substances called Auxins. In normal conditions, with sufficient light, the plant grows straight up, since the auxins are evenly distributed. But in the above mentioned case, light does not fall evenly on all sides of the plant. More auxins accumulate in the cells on the shady side, as compared to the other side. This causes the shady side to grow and elongate faster. This leads to the bending of the plant shoot towards the light.

Answered by  | 29th May, 2009, 09:00: PM

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