Question

Example from a previous chapter: What can be said about the leading versus the lagging strand in DNA population? A) The leading strand is replicated continuously for the entire length of the chromosome, while the lacking strand is replicated in pieces B) The lagging strand is synthesized in a semiconservative fashion while the leading strand is synthesized in a conservative fashion. C) Synthesis of the lagging strand requires more helicase enzymes than synthesis of the leading strand. D) The lagging strand has a higher mutation rate than the leading strand. The correct answer is A. Answer is wrong because DNA replication happens in a semi-conservative manner for all DNA molecules. Answer is wrong because only one helicase is needed at the replication fork. Answer Dis wrong because there is only one type of DNA polymerase to elongate the new DNA strands, and it has a fixed mutation rate. Question 2 1 pts • This question focuses on the structure and function of ncRNAs. • This question is asking you to weigh and judge, or evaluate the functions of various ncRNA to determine which one most likely has several stem loop structures. An ncRNA consists only of several stem loop structures. What is a likely function of this ncRNA? A) Regulating transcription by guiding histone modifying complexes to specific target genes. B) Inactivating the X chromosome in mammals by binding to DNA C) Binding to other ncRNAs and preventing them from performing their function. D) Inhibiting translation by binding to an mRNA E) Binding to components of the ribosome and facilitating its assembly HTML Editor BIA-A-LE* XX - Paragraph - MacBook Air

hi! it has to be answered in the format shown above the question. so you say the correct answer but then you go through each one and say why the other choices are incorrect one by one.

Answer 1

The answer to Question 2 is option is option D Inhibting translation by binding to mRNA

The miRNA have several stem loop structures and is involved in inhibition of tranlsation by binding with mRNA and degrades or destabilizes the mRNA by cleaving it or by shortening its poly A tail or by reducing the efficiency of the translation process.

The rest of the options belong to other ncRNA which do not have several stem-loop structures. The only option that may give a doubt is to consider tRNA is made of stem loop structure but it is limited to only 3 stem loops in its structure.

option 1A)  Regulating transcription by guiding histone modifying complexes to specific target genes it is done by lncRNAs (long non coding RNA) whose structure have several stem loops but also has single stranded regions in contrary to the questions' requirement of only several stem loops.

1B) Inactivating the X chromosome in mammals by binding to DNA is carried out by xist ncRNA which are also long ncRNA have only two stem loop structures in addition to big circular structures and again does not satisfy the condition.

1C) Binding to other ncRNAs and preventing them from performing their function this is carried out by snoRNA they modify the chemical structures of other ncRNA. Their structure includes stem loop, stem box and single stranded regions.

1D is the answer as discussed.

1E)  Binding to components of the ribosome and facilitating its assembly - rRNA forms the majority of the ribosomal structure which are dense circular structures, tRNA partially forms a part of the ribosome and facilitates translation although they have only 3 stem loop structures and also they do not help in the assembly of ribsome per se.