What will be the sequence of mRNA produced by the following stretch of DNA? [2019]
3′ ATGCATGCATGCATG 5′ TEMPLATE STRAND
5′ TACGTACGTACGTAC 3′ CODING STRAND
3′ AUGCAUGCAUGCAUG 5′
5′ UACGUACGUACGUAC 3′
3′ UACGUACGUACGUAC 5′
5′ AUGCAUGCAUGCAUG 3′
Match the following RNA polymerase with their transcribed products: [2019]
1. RNA polymerase I — (i) tRNA
2. RNA polymerase II — (ii) rRNA
3. RNA polymerase III — (iii) hnRNA
Select the correct option from the following:
1 - i, 2 - iii, 3 - ii
1 - i, 2 - ii, 3 - iii
1 - ii, 2 - iii, 3 - i
1 - iii, 2 - ii, 3 - i
Select the correct statement. [2018]
Franklin Stahl coined the term “linkage”.
Punnett square was developed by a British scientist.
Spliceosomes take part in translation.
Transduction was discovered by S. Altman.
(2)
Franklin Stahl along with Matthew Meselson proved semi-conservative mode of replication in DNA. Punnett square was developed by a British geneticist, Reginald C. Punnett. Spliceosome formation is part of post-transcriptional change in eukaryotes. Transduction was discovered by Joshua Lederberg and Norton Zinder in the bacterium Salmonella.
AGGTATCGCAT is a sequence from the coding strand of a gene. What will be the corresponding sequence of the transcribed mRNA? [2018]
AGGUAUCGCAU
UGGTUTCGCAT
ACCUAUGCGAU
UCCAUAGCGUA
(1)
Coding strand and mRNA have same nucleotide sequence except, ‘T’ – Thymine is replaced by ‘U’ – Uracil in mRNA.
Which of the following RNAs should be most abundant in animal cell? [2017]
tRNA
mRNA
miRNA
rRNA
(4)
rRNA (ribosomal RNA) is the most abundant of all types of RNA (70–88%). Hence, it will be present in highest amount. Percentage of tRNA and mRNA is 15% and 2–5% respectively. miRNA (micro RNA) are 21–22 bp long RNA that bring degeneration of mRNA.
Spliceosomes are not found in cells of [2017]
fungi
animals
bacteria
plants
(3)
Spliceosomes help in removal of introns. They will not occur in prokaryotes because prokaryotes do not have introns and thus, processing does not require splicing of mRNA.
The equivalent of a structural gene is [2016]
muton
cistron
operon
recon
(2)
Cistron (or gene) is a length of DNA that contains the information for coding a specific polypeptide chain or a functional RNA molecule (i.e., transfer RNA or ribosomal RNA). Hence, cistron is a unit of function. Currently such a gene is called structural gene.
Which of the following rRNAs acts as structural RNA as well as ribozyme in bacteria? [2016]
5S rRNA
18S rRNA
23S rRNA
5.8S rRNA
(3)
23S rRNA acts as structural RNA as well as ribozyme in bacteria.
DNA-dependent RNA polymerase catalyses transcription on one strand of the DNA which is called the [2016]
template strand
coding strand
alpha strand
antistrand
(1)
The strand of DNA on which RNA polymerase binds to catalyse transcription is called template strand. It is also known as master or antisense strand. It has the polarity of 3′ → 5′.
Select the correct option. [2014]
Direction of RNA synthesis - 5′ – 3′
Direction of reading of the template DNA strand - 3′ – 5′
Direction of RNA synthesis - 3′ – 5′
Direction of reading of the template DNA strand - 5′ – 3′
Direction of RNA synthesis - 5′ – 3′
Direction of reading of the template DNA strand - 5′ – 3′
Direction of RNA synthesis - 3′ – 5′
Direction of reading of the template DNA strand - 3′ – 5′
(1)
RNA polymerase initiates and extends the RNA (chain elongation) and functions always in 5′ to 3′ direction. The structural component of DNA has 3′ to 5′ polarity. It is also called template DNA strand or antisense (–) strand.
