I would say the last one. Yes, the coral reef in the south is being threaten but, it’s not the only one. Many other reefs are being threatened. Why? To find the problem to this reef you need to find the problems of other reefs and compare the data. Which ever the most problem cause you get rid of that first.
Answer:
Much change is due to random genetic drift rather than positive selection. Some are harmful and are likely to be eliminated by natural selection – by death of the embryo, for instance. ...
Answer:
The elemental is required in very small amount. (Ans. A)
Explanation:
Trace element is also known as micro-nutrient. It is also defined as any chemical element required by living organisms in a minute or small amounts which is usually part of the vital enzyme (cells produced by catalytic protein).
Exact needs of trace elements vary among species, like commonly required plant trace elements are cooper, zinc, manganese, boron, and molybdenum. Animals commonly required iodine, manganese, and cobalt.
Absence of necessary plant trace elements required by plants in the soil causes deficiency disease, lack of animal trace elements used by animals in the soil may not harm plants, but, animals feeding on those plants develop their deficiency disease.
So, the adjective trace means that the elemental is required in a very small amount.
