Answer: False
A lake is a water body that is surrounded by land. The water in the lake comes from melting glaciers, rain, groundwater, rivers. Lake formation also occurs when a water body is restricted to it's natural flow. Erosion due to wind and water will limit the life of lake. As, soil removed during landslides or mudslides from hills or mountains get settled as debris at the bottom of lake will cause water pollution. Also, soil coming from agricultural field through water will carry in it fertilizers ,which will promote excessive plant and algal growth in lakes therefore, oxygen content of lake water will decrease which lead to death of animals residing in lake hence, will ultimately lead to water pollution ,which will be responsible for limiting the life of lake.
An atom is unlikely to react when it is stable. That is when it's shell is complete. Due to the completion of the shell, no other electron can combine through any form of bonding. Hope i helped.
DDT stands for dichloro-diphenyl-trichloroethane. The first kind of synthetic/artificial insecticides came into use in the 1940s. The earlier usage of DDT include: a) Killing of malarial vectors, b) Combatting Typhus and other insect borne human diseases, c) As a pest control in crops d) as a pest control in garden, live stock production and even at homes.
The negative impact of DDT could be felt for the first time when the pests that were earlier killed by use of DDT have now become pesticides resistant. In the 1950s in USA, the regulatory measures were adopted to reduce the usage of DDTs as its effects as a pesticides were no more long significant and also it was creating detrimental physical and psychological impacts on the human and environment.
It was in 1972 that the U.S. Environmental Protection Agency cancelled the order for banning the usage of DDT based on the adverse impact it produced on the environment, human and other life forms. Since then continuous studies are being conducted to analyse the impact of DDTs. In some later years it was established that DDT is the cause of producing tumors in liver.
Some of the common negative impacts produced by DDT as per the U.S. Department of Agriculture :
a) The non destructive nature – DDT can not be destroyed and thus it remains persistent in the atmosphere
b) It attacks the tissues of living organisms especially the animals and humans ( fatty tissue)
c) It can penetrate the atmosphere to deeper extent.
Now as per the current stuation, The use of DDT is controlled and other alternatives of pest control organisms is being deduced. As per the treaty of Stockholm Convention on POPs (Persistent organic pollutants) , usage of DDT for malarial control is justified but it puts a restrictive use of DDT as pesticides in other areas.
Well to I don't know what you mean by in the following cases but, a dependent variable is the variable being tested and measured and also relies on the independent. While on the other hand the independent variable is the variable that is being changed or controlled.
Insulin receptors regulate glucose level in blood. Without that, glucose level would uncontrolled (not normal) (high and low) and it would be impossible to maintain homeostasis. I Hope I Helped You Good Luck.
