Most respiratory illnesses are spread primarily through contact, droplets, or through the air.
Answer: The correct answer is (D) Both A and B
Explanation:
When an axon is depolarized at halfway to the threshold level,the action potential will be generated that would travel 'downstream' i.e towards the synapse and 'upstream' i.e back towards the cell body. This is because both channels on either sides are not under refractory period,i.e they are open.
The correct answer is B.
Air pollution can cause cardiovascular diseases as the pollutants in the air can damage your heart and lungs. This isn't always the case but if you live in a highly polluted area you are running the risk of developing a cardiovascular disease as well as other diseases related to the inhalation and exposure of toxins and chemicals in the air.
