The answer is an enzyme.
When cutting DNA, scientist uses enzymes called restriction enzymes. These enzymes are naturally produced in bacteria as a defense against phages. So, enzymes cut DNA of the phages and thus inactivate it. Also, these enzymes do not cat DNA randomly, but on specific sites. This characteristic of restriction enzymes is used for some molecular biology techniques. All species' DNA contains target sites of restriction enzymes, but most organisms do not have restriction enzymes. Therefore, restriction enzymes are suitable for different techniques.
Answer:
The most effective experimental approach to assess the effects of elephant impact on vegetation is to assess plant responses under differences in elephant density. It is important that other factors, such as soils or habitat structure are held constant so that the only factor which varies is elephant density.
Explanation:
source: Studying Elephants icun.org
Answer:
Viruses use their own catabolic enzymes.
Explanation:
Viruses are the infective particles present in the environment which encloses their genetic material which could be wither RNA or DNA enclosed in the protein coat.
The protein coat is made of the capsomers which are arranged in the tubular structure forming capsid. The viruses do not contain the metabolic machinery of their own that is the reason that they do not have replication or transcription or translation machinery. For this they are dependent on the host organisms as they use their machinery.
Thus, the selected option is correct.
Answer: number 1
Explanation: that is when we could first sustain life because that is when we gained atmosphere and when we could hold carbon and oxogen