Answer: A protein domain is a region of the protein's polypeptide chain that is self-stabilizing and that folds
independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist of several domains.
One domain may appear in a variety of different proteins. Molecular evolution uses domains as building blocks and these may be recombined in different arrangements to create proteins with different functions.
In general, domains vary in length from between about 50 amino acids up to 250 amino acids in length.
The shortest domains, such as zinc fingers, are stabilized by metal ions or disulfide bridges. Domains often form functional units, such as the calcium binding EF-hand domain of calmodulin.
Because they are independently stable, domains can be "swapped" by genetic engineering between one protein and another to make chimeric proteins.
The variety of all life forms on Earth.
Answer:
Crossing over is a biological occurrence that happens during meiosis when the paired homologs, or chromosomes of the same type, are lined up. Hope this helps :)
Explanation:
The correct answer is (a.) liver. The liver contains the tubules with sinusoids which is lined with macrophages that leads to the central venous structure. A liver is a vital organ that serves as a gland that plays an important role in animal's and vertebrae's metabolism.
