Answer:
Explanation:
Endocrine cells in the pancreas are referred to as Islets of Langerhan. There are two major types; Beta cell that produce insulin and alpha cells that produce glucagon.
They are identified when viewed under slides based on their colour reactions with histological dyes. Tinctorial techniques that can be used to identify them under microscope includes; Mallory-Heidenhain azan trichrome, chromium hematoxylin and phloxine, aldehyde fuchsin, and silver impregnation methods.
Islets of Langerhan cells make up minority of the cell. Majority of them are for exocrine functions.
Because they want to know the existence of aliens
Answer:
growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone, follicle-stimulating hormone, luteinizing hormone, and prolactin.
Explanation:
The skin acts as a barrier for protecting the body from the harmful things such as sun rays, moisture, cold.
<u>Explanation:</u>
Skin plays an important role in regulating body temperature. It helps to prevent harmful substances enter into our body, and does not allow to loss water in our body. Its form the barrier that prevents harmful substances and microorganisms enter in our body.
Our skin is the protecting layers and against loss of water and blood from our body. Its help us to maintain the constant body temperature. The important role of the skin us to protect our body from the ultraviolet rays.
Answer:
The correct answer is : A.
Explanation:
- This is because of the following reasons:
- Escherichia coli is a bacteria and hence is a prokaryote.
- The cloning of human (eukaryote) genes is done to obtain in-vitro protein expression which are to be used a pharmaceutical compounds.
- Although the phenomenon of Central Dogma takes place in both Prokaryotes and Eukaryotes, the mechanism is very different.
- Some of the differences includes:
- Eukaryotic genes contain certain non-protein encoding sequences called the Intron sequences which needs to be removed from the transcribed mature mRNA by Spliceosome. This phenomenon is absent in prokaryotes as they do not possess introns. Hence, proper processing of eukaryotic mRNA is not possible in prokaryotes.
- The mature eukaryotic mRNA has a 5' cap and 3' polyadenylated tail which is added by a capping enzyme and a poly-A polymerase enzyme to increase their stability. This will not be possible in a prokaryote as they lack these enzymes.
- The translation of membrane proteins and secretory proteins is carried on by the ribosomes bound to the endoplasmic reticulum. This structure is absent in prokaryotes, hence they will be unable to produce a proper polypeptide sequence.
- Finally, the eukaryotic proteins undergo various modifications after formation, like methylation, acetylation, etc. These reactions cannot be carried out in a prokaryote as they lack the respective enzymes.
- Hence, we see a properly folded functional eukaryotic protein cannot be produced in a prokaryote.
