Biology 1 Marks Question

Transcription: The process of copying genetic information from one strand of the DNA into RNA is known as transcription. RNA is assembled simply based on complementarity of the DNA strand, only uracil is substituted in place of thymine. Only a small segment of DNA that codes for a polypeptide is copied.

Promoter: It is a region of DNA that helps in initiating the process of transcription. It serves as the binding site for RNA polymerase.

mRNA: 5'-A U G CAU G CAU G C AU G CA UGCAUGCAUGC-3'.

Translation: It refers to the process of polymerisation of amino acids to form a polypeptide. The order and sequence of amino acids are defined by the sequence of bases in the mRNA. It occurs in cytoplasm in both prokaryotes and eukaryotes.

tRNA: tRNA or transfer RNA is a small RNA that reads the genetic code present on mRNA. It carries specific amino acid to mRNA on ribosome during translation of proteins.

The DNA strands are complementary to each other with respect to base sequence. Hence, if the sequence of one strand of DNA is 5'-ATGCATGCATGCATGCATGCATGCATGC-3’ Then, the sequence of complementary strand in 5' to 3' direction will be 3'-TACGTACGTACGTACGTACGTACGTACG-5’ Therefore, the sequence of nucleotides on DNA polypeptide in 5' to 3' direction is 5'-GCATGCATGCATGCATGCATGCATGCAT-3’.

Polymorphism: The variation in DNA arising through mutation at non-coding sequences is known as Polymorphism. Such variations are unique to specific sites of DNA and can occur due to deletion, insertion or substitution of bases. It can be observed by making fragments of DNA sample and separating them through electrophoresis. The polymorphism in a DNA sequence is the basis of genetic mapping of the human genome as well as DNA fingerprinting.

Exons: Exons are the coding sequences of DNA that are transcribed and translated.

Bioinformatics: It is the application of computer science and information technology which deals with handling, storing of huge information of genomics, processing information, analyzing data and creating new knowledge.

The OH-group is present at the 2-position.

AUG.

Ribosomes.

False.

True.

Sometimes cattle or even human beings give birin to their youngones that are having different sets of organs like limbs/ position of eye, etc. It happens due to the disturbance in coordinated regulation of expression in sets of genes, which are associated with organ development .

After splicing, tailing occurs at the 3' end of hnRNA.

Intron is considered to be the reminiscent of antiquity.

The precursor RNA transcribed by RNA polymerase that contains both exons and introns.

In semiconservative DNA replication, each replicated DNA molecule consists of an old and a new strand i.e., one parental strand and one newly formed daughter strand.

DNA is a giant molecule and there are technical limitations in sequencing very long segments of DNA; hence DNA has to be cut into smaller fragments.

Methionine and tryptophan.

Polynucleotide phosphorylase.

RNA polymerase can polymerise the RNA strand only in 5' → 3' direction.

The triplet base present on the tRNA which is complementary to codon on mRNA is called anticodon.

Transformation is a phenomenon by which the DNA isolated from one type of cell, when introduced into another type, is able to bestow some of the properties of the former to the latter.

Uracil 'U'.

DNA replication takes place during s-phase of the cell cycle.

The RNA polymerase-II transcribes the precursor of mRNA, the heterogeneous nuclear RNA (hnRNA).

Elongation step in transcription is catalysed by the enzyme DNA-dependent RNA polymerase.

Sickle cell anaemia/Thalassemia/Phenyl ketonuria.

Guanine pair with cytosine and adenine pair with thymine.

A segment of DNA, Coding for a polypeptide.

Eight.

Lysine and arginine.

During conversion of hnRNA into functional mRNA, at 3’ end.

Synthesis of polypeptide chain terminates when a nonsense codon of mRNA reaches the A-site. There are three nonesense codon UAA, UAG and UGA, which are not recognised by any of the tRNAs. Therefore no more amino-acyl tRNA reaches the A site. The P site t-RNA is hydrolysed and the completed polypeptide is released in the presence of GTP dependent release factor.

Point mutation.

Caenorhabditis elegans.

Methionine, Tryptophan.

Griffith concluded that the R-strain bacteria had somehow been transformed by heat-killed S-strain bacteria. This must be due to transfer of genetic material.

Lagging strand (3' → 5').

The presence of 2'-OH group in every ribonucleotide makes RNA labile and reactive.

DNA was first isolated by Friedrich Meischer in 1869 who named it as nuclein.