In eukaryotes, transcription occurs in the nucleoid. (T/F) Chargaff\'s rules sta
ID: 87420 • Letter: I
Question
In eukaryotes, transcription occurs in the nucleoid. (T/F) Chargaff's rules state that the amount of DNA base pairs (G:C and A:T) varies from species to species. (T/F) The only difference between DNA and RNA is that DNA contains deoxyribose instead of ribose. (T/F) Gene expression can be regulated by post-transcriptional RNA editing/processing. (T/F) Gene expression can be regulated at the level of protein synthesis. (T/F) Three types of RNA (mRNA, rRNA, and tRNA) are required for translation. (T/F) Complimentary base-pairing is important for DNA replication, transcription and translation. (T/F) A point mutation is more likely to be damaging than a frameshift mutation. T/F The primary structure of a protein is encoded by the base sequence of DNA. T/F The DNA sequence 3'-TAC GAT -5' would be transcribed to RNA sequence: 5' ATG CTA-3' T/F The DNA code is considered unambiguous because a given codon only specifies one amino acid T/FExplanation / Answer
20) False
In eukaryotes, transcription occurs in the nucleus. Nucleoid is an irregular shaped region enclosed by a cell in prokaryotes which store the genetic material i.e DNA. It is analogous to nucleolus of eukaryotes.
21) True
Chargaff's second rule called as second parity rule states that the composition of DNA base pairs i.e nucleotides varies from species to species.
22) False
There are two differences between DNA and RNA which are as follows:
1) DNA contains four nucleotide bases namely adenine, thymine, cytosine and guanine. RNA also contains four nucleotide bases but the thymine is replaced by uracil.
2) DNA has deoxyribose sugar whereas RNA has ribose sugar.
23) False
Gene expression can be regulated by RNA editing at the post-translational level and RNA processing at translational level. Regulation by transcription factors and regulatory elements occurs at the post-trancriptional level.
24) True
Gene expression can be regulated at the level of protein synthesis (translation process). Proteins undergo various modifications such as phosphorylation, glycosylation, etc.
25) True
In eukaryotes, the three types of RNA are required for the synthesis of proteins. The translation of mRNA into proteins is carried by tRNA and ribosome (a constituent of rRNA that is made up of proteins).
26) True
Complementary base pairing is important to conserve the base sequence of DNA. Replication involves the synthesis of new DNA strand from the old template strand by complementary base pairing. In transcription, mRNA is formed by pairing with the complementary bases of DNA. In translation, tRNA forms the complimentary base pairing with the codons of mRNA.
27) False
Point mutation is caused by the deletion or addition of a single nucleotide base which is replaced by another nucleotide base whereas frameshift mutation is caused by the deletion or addition of more than one nucleotide bases.It shifts or disrupts the reading frame of codons (a triplet of nucleotides is known as a codon). Hence, a frame shift mutation is more damaging than a point mutation.