Answer:
The correct answer is "proteins are extracted from an environment, fragmented, and adaptors are added".
Explanation:
The missing options of this question are:
A) Software aligns sequences and assemble large portions of genome.
B) The samples are subject to polymerase chain reaction for amplification.
C) The sequences of the amplified fragments are determined by next-generation methods.
D) Proteins are extracted from an environment, fragmented, and adaptors are added
The correct answer is option D) Proteins are extracted from an environment, fragmented, and adaptors are added.
Metagenomic sequencing refers to the amplification and determination of all nucleotide sequences in a sample, which might contain multiple microorganisms and viruses in order to understand the presence and proportions of microbiota. Metagenomic sequencing involves the use of next-generation methods, to amplify and characterize all the nucleotides sequences. It is false to affirm that the proteins are extracted directly from the environment in this technique, since metagenomic sequencing is focused on the nucleotide sequences.
Answer: a) true
Explanation: The fluid inside the egg helps in the survival of embryo and maintain fluid environment.
Answer:
Because DNA polymerase can synthesize DNA strands in 5' to 3' direction only.
Explanation:
The 5' end of one DNA strand is present opposite to the 3' end of the other strand. But DNA polymerase enzyme can elongate the primers in 5' to 3' direction only. Formation of a phosphodiester bond between the existing nucleotide and the incoming nucleotide requires the free 3'OH. This 3' OH serves in the nucleophilic attack during the formation of the bond.
Therefore, the lagging strand is synthesized discontinuously in the form of short DNA fragments. These are called Okazaki fragments. Primers are formed for short distances which in turn are elongated by DNA polymerase to form the Okazaki fragments. On the other hand, the synthesis of the leading strand occurs continuously in the same direction in which the replication fork moves.
