Answer:
More exposure causes mutation in bacteria.
Explanation:
More exposure to the antibiotic by non-resistant bacteria causes change in its structure against the environment and as a result of that change the bacteria get resistance against that antibiotic. No, farmers should not be allowed to put low doses of antibiotics in animal feed because it has no effect on the antibiotic-resistant bacteria. The farmer should use another antibiotic on the antibiotic-resistant bacteria which they have no resistance.
The correct option is B.
In the ecosystem, energy flows from one trophic level to the other. The first trophic level is that of the producers which use the energy of the sun to produce their own food. Out of the energy obtained from the sun by the producers only about 3% of it is converted into food products. The second trophic level is made up of the herbivores and the omnivores which eat the plant. Only about 10% of the energy from the plant is transferred to the animals in the second trophic level. These second trophic level animals will also transfer about 10% of the energy they obtain to the animals in the third trophic level when they are eaten. Thus, it can be seen that the energy that is transferred in the ecosystem is gradually reducing from one trophic level to another.
Answer:
pH meter and pH paper.
Explanation:
There are a few other ways that are commonly used, including titration, but most are tedious and require detailed hands-on work. A pH meter is normally assisted by the use of a computer or a digital user interface. The use of pH paper can be likened to the use of a Galileo thermometer.
Answer:
A.The hole in the ozone layer
Explanation:
• Montreal protocol is an international treaty that was signed to control the use of substances that are resulting in the depletion of the ozone hole.
This treaty was signed in the year 1987 and became effective form 1989.
• Since the time that this treaty has come into force, there has been a significant improvement in the ozone hole that was observed over Antarctic as it's size has decreased.
• This improvement has been possible because the treaty helped to phase out chemicals such as chlorofluorocarbons, carbon tetrachloride, etc. that are responsible for ozone hole depletion.
They do not have external ears like us. but they do have ear holes located directly behind their eyes. frogs ear holes are covered with thin tympanic membranes or the eardrums that protect the inner ear cavity.
