Answer:
<h2><u>
directional selection</u></h2>
Explanation:
This type of natural selection is referred to as . In this type of natural selection, either one phenotype is preferred or the other; therefore, there is no equilibrium between the populations of the phenotypes that are present.
Examples of organisms that have undergone directional selection are black bears during the ice ages, African chichlid and sockey salmon.
I had a question like this so i'm rolling with (B)
Answer:c. Steroids/cholesterols and phospholipids
Explanation:
The cell membrane structure exhibit a fluid mosaic model due to the presence of two types of membrane lipids these are phospholipids and sterols like steroids/cholesterols.
A phospholipid is a kind of lipid that is made up of glycerol, two fatty acids in tail and a head group associated with the head group. The biological membrane forms two layers of phospholipids with their tails that points inwards and the arrangement is called as the phospholipid bilayer.
The cholesterol is the another membrane lipid in the cell membrane. It is composed of fused carbon rings present along the side of phospholipids.
It is believed that this happens because some signals that regulate development are the same between different species and because <span>they share ancient genes. </span>These ancient genes are expressed during a middle "phylotypic stage" of embryonic development for all species.
For example, human and animal embryos go through very similar stages of early development and share similar features such as tails and gill-like structures. The major difference appears to be how long it takes to reach each of these same stages.