Only plants have chloroplast and a cell wall
<span>Cattle and sheep are exposed to lead and zinc when these poisons are in the grass/soil.
Cattle and sheep graze on the grass, and thus they intake these minerals, such as lead and zinc when they come in contact with grass or earth they may eat along with grass. Thus they are exposed to them via eating.
</span>
Answer:
D
Explanation:
D is the only option where the cause of the pollution is not something man-made.
<u>Answer</u>: an all or none response
According to the all-or-none law, it a certain threshol is crossed by a stimulus' strenght, it will cause a response in the nerve cell or muscle fiber. However, the strenght of the response will always be the same and will not vary with different stimulus strengths. The only requirement is for the threshold to be crossed.
Finish. The work is done then the work is finish.
