Answer:tailing at 3' end protects mRNA from attack by 3' exonuclease and 5' capping is useful for recognition of mRNA
Explanation:
The mRNA formed and released from the DNA template is known as primary transcript. In mammalian system, it undergoes intensive modification to become the mature mRNA.
Post transcription processing includes removal of Introns, splicing of exons, poly-A tailing at 3'end and capping at 5' end.
The Poly-A tailing at 3' end occurs in the nucleoplasm, the 3' end is polyadenlated involves with 20-250 nucleotides long. This tail protects mRNA from attack by 3' exonuclease activity
5' end capping end also is done in the nucleus. The cap is useful in recognition of mRNA by the translating machinery.
Answer:
The respiratory and circulatory systems bring oxygen and nutrients to the cells. The respiratory and circulatory systems work together to maintain homeostasis. The respiratory system moves gases into and out of the blood. The lungs contain the bronchi, bronchioles, and alveoli.
Explanation:
The production, maintenance and distribution of lymphocytes &The return of fluid and solutes from peripheral tissues to the blood.
The answer is A. The sulfur-filled fluid that comes from the vents is lethal to some animals.
Deep-sea vents are hydrothermal vents at the bottom of the oceans. The mineral water that comes from them is rich in sulfide and methane and can be lethal to the most of animals. However, some bacteria are able to survive in such conditions thanks to the process of chemosynthesis. Chemosynthesis is a process in which some bacteria produce sugar, similarly to photosynthetic process. But, while in photosynthesis the energy of Sunlight is used to convert carbon dioxide and water into sugar and oxygen, in chemosynthesis, carbon dioxide, oxygen, and hydrogen sulfide are used to produce sugar, along to water and sulfur. This process is preferable when there is no light and the environment is rich in sulfide or methane, such in deep sea vents.