A dichotomous key helps you identify unknown specimens based on their traits because there are only two options available per trait. Selecting one from the two options (usually contrasting characteristics) from each step leads to smaller and smaller groups until the option is reduced to single and unique trait of an organism.
Considering you need to identify an organism. So, on the top of they key is animal with options: (a) with red blood cells and (b) no red blood cells. The option you will select is no red blood cells and under option b, you’re given two choices again: (a) hard bodies and (b) soft bodies. You’ll select soft bodies, then two options again are given: (a) with shell and (b) without shell. The option you’ll select would be without shell, and so on.
The structure is a phospholipid bilayer. There are many phospholipids which contain a water loving phosphate end and a water hating lipid (fatty) end. The phosphate ends all point out words while the fatty ends are inside.
The purpose is protection of the cell as well as allowing certain molecules to enter and exit the cell
A tissue that appears to have long fibers that appear striated, with the nuclei are pushed off to the side of the fibers is a Skeletal muscle.
The cells of a Skeletal muscle are large,long and <span>cylindrical</span>
<span>and appear striated (banded)
They are also attached to bones</span>
