<span>Messages to the brain travel along the nerves, which are strings of long thin cells called neurons</span>
Distribution of phenotypes within a population may be impacted by different types of natural selection. These types of selection include;
Directional selection involves a change in the environment shifts of phenotypes observed. Example is the giraffe neck-length, where the length got longer and longer over time to reach the leaves at the top of trees.
Stabilizing selection , this is a selection where an average phenotype is favored. example is number of eggs laid by birds such that too many eggs will be a waste of energy because some chicks would starve.
Disruptive selection is a selection where individuals with an average value of a trait are affected most while those with values below average are affected least. Example small individuals are capable of hiding from predators while big individuals can not fit in the hiding place but instead will fight with predators.
There are two basic types of ER. Both rough ER and smooth ER have the same types of membranes but they have different shapes. Rough ER looks like sheets or disks of bumpy membranes while smooth ER looks more like tubes. Rough ER is called rough because it has ribosomes attached to its surface.
<span>The double membranes of smooth and rough ER form sacs called </span>cisternae. Protein molecules are synthesized and collected in the cisternal space/lumen<span>. When enough proteins have been synthesized, they collect and are pinched off in </span>vesicles<span>. The vesicles often move to the Golgi apparatus for additional protein packaging and distribution. </span>
Smooth ER (SER)<span> acts as a storage organelle. It is important in the creation and storage of lipids and </span>steroids<span>. Steroids are a type of ringed organic molecule used for many purposes in an organism. They are not always about building the muscle mass of a weight lifter. Cells in your body that release oils also have more SER than most cells. </span><span>
God Bless:)</span>
