Answer: (B) Pre-zygotic; post-zygotic.
Explanation:
Prezygotic isolation occurs before fertilization of eggs. It occurs between the two sex gametes and deter sexual reproduction between different species.
However, individuals are considered to be diverge on the phylogeny tree and different species, when they cannot reproduce.
Mechanisms of prezygotic isolation include habitat isolation, gamete isolation, mechanical isolation, behavioral isolation, and mating seasons.
Whereas, postzygotic isolation prevents the formation of fertile offspring. This phenomenon leads to production of an hybrid offspring from different species and this is a form of speciation in nature.
Mechanisms of postzygotic isolation include hybrid inviability, hybrid breakdown, and hybrid sterility.
Answer:
1. Space-filling
2. Ribbon model
3. Wire frame
4. Simple shape
5. Simplified diagram
Explanation:
"attached is the question"
A protein can be visualized using different types of models. The models you use will depend on what you want the viewer to understand. A space-filling model would show all the atoms that composes a protein. This type of model makes use of spheres, emphasizing the globular structure of the atoms. They are proportional to the actual size of the atom they represent. Each type of atom is a different color. Even the distances of the spheres are proportional to its size to help viewers better see the actual shape of the protein. Ribbon model is also a 3D representation of a protein. It shows the only the backbone of the protein. It highlights the folds and coils in a protein, generally the organization. Some versions show the α-helices as ribbons and β-strands are shown as arrows. Wire frame model is like the ribbon model but it also shows the side chains. It shows the different atoms that are involved. Thin wires show the bonds made between the atoms and the wires bend show the relative location of the atoms. A simple shape focuses more on the function of the protein overall rather than the internal structures. The shape does not represent a particular protein, merely using a general shape to represent a protein. A simplified diagram shows more detail than the simple shape. It shows the internal structures as well but like the simple shape model, it focuses more on the function of the protein. A version of it is a solid shape, which does not show the internal structure.
Protects brain and spinal cord from trauma, as well as supplies nutrients to nervous system tissue. It also removes waste from cerebral metabolism.
