Answer:
a. mimicry
Explanation:
Stick bugs are perhaps one of the better known examples of insect mimicry. Their twig-like appearance helps to defend them against predators that hunt by sight.
This question is rather subjective: the answer depends on how the question is interpreted. Many people would say climate change is the greatest risk to water supply, but the question mentions 'Earth's water supply'. It is a fact that the amount of water on Earth has not changed. Climate change is shifting climatic patterns, so some areas experience more droughts, whereas others experience more floods, but the amount of water on Earth still stays the same. My answer is therefore that pollution poses the greatest risk to Earth's water supply. Pollution decreases the amount of water we can safely use without expensive treatment. Some water pollution, such as certain toxic metals, pesticides or endocrine disruptors, simply can't be detected or treated using conventional water testing and treatment. Modern civilisation is resulting in unsustainable amounts of pollution being released into our rivers and lakes, and sooner or later, a threshold of no return will be reached, where ecological collapse will mean we won't be able to rely on these water resources for fresh water anymore.
A bacteria is a prokaryotic microorganism that can either be beneficial, or harmful to the body. A virus is acellular, and has no cellular structure, and needs a living host to survive; it causes illness in the host, which causes an immune response. Bacteria are alive and can be treated with an antibiotic if it is harmful to the body. Since viruses are considered nonliving, the virus itself cannot be eliminated, but the symptoms can be treated. Another thing a virus can do that a bacteria can't is genetically program itself into the cells, which means that if you get it once, the symptoms can show up throughout the course of the human's life.
Answer:
example of active immunity is a)vaccine
The hormone is called adrenaline