The correct answer is "<span>a layer of smooth </span><span>muscle".
</span>In an individual's mouth, gut, and the small intestine, the mucosa, which holds tiny glands, which secrete juices in order to assist in digesting food<span>. The </span>digestive<span> tract also holds a layer of smooth </span>muscle, which <span>aids in breaking down </span>food<span> and move it along the digestive tract.</span>
Organisms eat plants, which is comprised of carbohydrates; those carbohydrates come from Carbon<span> dioxide in the atmosphere. Thus, an abiotic factor (</span>carbon<span>dioxide) helps create a </span>biotic<span> factor (the plants made out of carbohydrates).</span>
Idk the options but it could be genetic variation
If it is a healthy environment then the atmosphere will be happy meaning no dirty streets etc
