The X can possibly be the sex chromosome. Like for human female we have the XX chromosomes and when the allele is on the X chromosome we write as X with a R as the superscript on top right.
The Alveolar macrophages, Cilia and the mucus layer
The part of the brain that controls body movements and process information from the sense organs is : 1. Cerebral Cortex
Basically, Cerebral cortex is the part of the brain that control all conscious movement of your body
Hope this help
They pollinate plants, which saves farmers work. Insects such as bees and butterflies help to pollinate plants.
Clouds are formed when air contains as much water vapor as it can hold. This is called the saturation point, and it can be reached in two ways. First, moisture accumulates until it reaches the maximum amount the volume of air can hold. The other method reduces the temperature of the moisture filled air, which in turn lowers the amount of moisture it can contain. Saturation, therefore, is reached through evaporation and condensation, respectively. When saturation occurs, moisture becomes visible water droplets in the form of fog and clouds.
(weather.gov) talks about more for a better understanding!