Answer:
Non-coding DNA regions play important roles in regulating transcriptional activity by encoding different types of non-coding RNAs (ncRNAs), acting as scaffold attachment regions, acting as enhancer specific regions, etc.
Explanation:
Historically, it had been believed that non-coding DNA sequences were 'junk DNA' since they don't encode for proteins (beyond the sequences that are transcribed into functional non-coding RNAs, i.e., transfer RNA and ribosomal RNA). However, in the last years, it has been shown that non-coding DNA sequences play critical roles in regulating gene expression and genome function. For example, evolutionary conserved non-coding RNAs (ncRNAs) with regulatory roles on gene expression such as, for example, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been mapped in non-coding DNA sequences, thereby evidencing the functional significance of these regions. In consequence, the conservative nature of certain non-coding DNA sequences evidence that mutations in such regions may have significant deleterious effects, and thereby they could have a negative impact on the fitness of the individual.
Answer: Option C
Explanation:
Protein building begins on the DNA strand. Usually, the DNA contains genetic information which flows from nucleic acids to proteins in a series of steps:
1) Replication: this is the first step. It involves the copying of parental DNA into daughter copies.
2) Transcription: this is the second step. Here, parts of the coded genetic message in DNA are copied precisely in the form of RNA - in the form of messenger RNA (mRNA).
3) Translation: this is the third step. Here, genetic message coded in mRNA is translated, on the ribosomes, into a protein with a specific sequence of amino acids.
Simply put, DNA makes RNA, and RNA makes protein.
Answer: It is because it makes it more efficient to study organisms.
Explanation: Biologist classify organisms by considering similarities between them. The organisms which have closely related characteristics are placed in a separate domains by biologists. Domains are further divided into 6 Kingdoms. According to modern classification system, domain is largest unit of biological classification.
