Answer:
The correct answer d. one of the atoms sharing electrons is much more electronegative.
Explanation:
If one of the atoms is more electronegative than the others, like the oxygen in the water molecule, it will allow this atom to attract the other's electrons turning itself into a negative pole and turning the others into a positive pole. In the water, oxygen is more electronegative and that's why it becomes the negative part and the hydrogens become the positive.
Prophase, metaphase, anaphase, and telophase
Answer:
The answer is 'D'- Unusual number of sick or dying people.
Explanation:
Biological incident can be defined as <em>diseases which occur naturally in humans or are spread through terrorist motives</em>. There are lot of red flags which should be noticed before the disease reaches a peak limit.
The first sign of a biological incident will be reported by the medical authorities as there will be a <u>large number of people getting sick or dying</u>.
Either the deaths will be caused due to spread of a communicable disease or a biological agent has been released on purpose.
Dissolved oxygen refers to the oxygen present in water which is necessary for many forms of aquatic life. Any change in the amount of dissolved oxygen affects the aquatic life.
Fishes, invertebrates and the aquatic plants need dissolved oxygen for respiration. Microbes like bacteria and fungi also require it for the breakdown of organic matter. A decrease in dissolved oxygen affects the growth, reproduction of fishes and mortality of fishes rises. This results in the accumulation of dead fishes called the fish kill leading to water pollution. Decrease in dissolved oxygen also affects the growth of other aquatic forms and results in the accumulation of organic material in the water body. This is because it results in increased BOD (biochemical oxygen demand) which is the amount of oxygen required by the aerobic microorganisms to breakdown the organic matter.