<span>A: food chain
</span><span>In many functions of a living organism, it cannot make its own energy. It uses energy from its environment, retrieves and converts into a usable and edible matter. Organisms that can do this process is the autotrophs, they can facilitate photosynthesis which they gather energy from the sun, water and carbon dioxide in order to create energy by then, the transfer of this energy to other organism is played by the food chain –food web. </span>
Cells are the basic unit of structure and function in organisms.
Needless to say, organisms can’t be a thing if cells didn’t exist.
A gymnosperm is <span>a plant that has seeds unprotected by an ovary or fruit. Gymnosperms include the conifers, cycads, and ginkgo.</span>
The t<u>unica media</u> is composed of an endothelial layer that is continuous with the endocardium of the heart.
<h3>What is tunica media?</h3>
Collagen, elastin, and smooth muscle cells make up tunica media. It is located halfway between the tunica externa and the tunica intima. The transverse arrangement of its strands and color make the middle coat (tunica medium) distinct from the inner (tunica intima). It not only supports the vessel but also alters the vessel's width to control blood pressure and flow.
Elastic fibers make up the majority of the tunica media in bigger vessels. The number of elastic fibers reduces as arteries get smaller, whereas the number of smooth muscle fibers grows. The strongest of the three layers is the tunica adventitia, which is the top layer. Elastic and collagenous fibers make up its structure.
Learn more about tunica media here:
brainly.com/question/15395381
#SPJ4