Restriction enzymes and or restriction endonucleases are involved at recognizing specific sequence of nucleotides and cutting or splicing them at appropriate regions to produce fragments that can either be sticky ends or blunt ends depending on where they cut and the nature of nucleotides involved within the fragments. They play an important role in genetic engineering, as geneticists can use them for placing into extra chromosomal information and or content of plasmids in certain bacteria, from other sources, for instance antibiotics, grow and or produce many individual colonies of bacteria, isolate them and one would have many sequences for instance that can code for an antibiotic that can be extracted and used further. Assuming the bacteria's plasmid can take in that sequence.
If a species is said to be extinct, then that species is reduced to zero. There are none living in existence. The affects to other organisms of its extinction would depend on their value to the ecosystem. Regardless, extinction completely stops evolution of the species extinct.
4 i guess........................
Answer:
In most trees, the area just under the bark layer contains moisture in the form of sap and water. And since water is a better electrical conductor than wood, lightning striking a tree tends to travel just underneath the bark.
The list that is composed of substances that are widely used for many years without apparent ill effects is the GRAS. GRAS is an abbreviation for generally recognized as safe; it is an American food and drug adminstration designation where chemical or substance added to food is considered safe by experts, and therefore, it is exempted from the usual federal food, drug, and cosmetic Act.
