Answer: Option A
Explanation:
When Andrew was exposed to the virus causing chicken pox he got infected and the virus crossed the blood brain barrier.
During the early stages when Andrew was a child there will be as such no effect of the virus in the brain.
During the early stage the virus will remain in the brain and cause harm in the later days when Andrew will be older.The virus can alter the brain functions such as homeostasis, blood brain barrier functions.It enters the brain while damaging the nervous system.
Answer:
A lunar eclipse can only occur when there is a full moon.
Explanation:
A lunar eclipse occurs when the Moon, Earth and Sun are aligned on a straight line. This alignment completely blocks the sunlight and moon is under the shadow of Earth. In this phase, moon often look red because of reflection of infrared radiations. This happens only where there is a full moon.
It is not possible to occur moon eclipse in any phase because if sunlight would reach the moon surface directly, it is not a moon eclipse Further, lunar eclipse can last upto a few hours because the shadow of Earth is greater because of its size compared to the moon's size and it takes a while until moon is completely out of that shadow. Lastly, a lunar eclipse doesn't create an eerie color in the sky rather a red color due to infrared radiations.
Answer:
Overfishing is one of the major concern no a days in aquatic systems. overfishing is resulting in the extinction of aquatic organisms and it can lead to several damage to other living organism.
Prawns and small fishes are important organisms in food web or in aquatic system as they maintain the bacterial level or other microorganism level in control.
Prawn and small fishes utilize oxygen and nutrients present in water to survive, if they will get extinct the amount of nutrient and oxygen left will be used by the bacteria and mold living in the system which can have bad impact on human and other organism.
Heron and pelican populations depends on prawn and small fishes for survival as they feed on them and when there will be not sufficient population of prawn and small fishes, there are chances that heron and pelican populations can also get extinct.
The answer is rain percolates through the pavement into the ground below, causing cracks in the pavemen
