Bronchoconstriction happens when smooth muscles around the lungs constrict and block the flow of air in the lungs. This can happen because of internal factors due to diseases such as asthma and inflammatory diseases, but it can also be caused by external factors such as changes in humidity, temperature, and pressure of the air and also excessive workout.
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pollen is important in fertilization because pollen carries male gamete and it helps in transportation of male gamete during fertilization in mainly gymnosperms and angiosperms.
A role in ones environment is a niche
<span>(2) increased exposure to ultraviolet light. The ozone layer protects us from UV light.</span>
The answer is 1. hope this helps