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Correct answer is (a) MUTATIONS

To elaborate: POLYMORPHISM arises DUE to mutations. It can also be known as the discontinuous variation that is seen among the INDIVIDUALS of a species.

Correct answer is (a) True

The explanation: The small peaks formed by the DNA when kept in the DENSITY gradient centrifugation are CALLED as satellite DNA. These DNA sequences do not code for proteins. On the contrary, they form a large PORTION in the GENOME of humans.

Correct option is (b) Repetitive DNA

The best explanation: In DNA finger printing, the differences in the SPECIFIC regions of the DNA sequence are called as Repetitive DNA. In this part, a small structure of the DNA is repeated many TIMES. These repetitive STRUCTURES can be separated from the bulk genomic DNA. This is done by observing the different peaks ACHIEVED by them during the density gradient centrifugation.

Correct option is (a) True

To explain I WOULD SAY: DNA contains many repeated sequences in it. Sometimes it is noted to have more than hundreds or THOUSANDS of sequences in them. These sequences MIGHT not POSSESS any direct coding functions in them. This altogether makes the large portion of the human genome.

Right ANSWER is (a) 3164.7 million

Best explanation: NUCLEOTIDES are the organic carbon molecules. They contain both a NUCLEOSIDE and a PHOSPHATE group. Inside the human genome, there is a total of 3164.7 million nucleotides.

The CORRECT answer is (a) Based on microsatellites

The explanation: The genetic and the physical maps on the GENOME are assigned based on microsatellites. They are also assigned based on the act of polymorphism at the restriction endonuclease recognition SITES. The repetitive DNA SEQUENCES are called as microsatellites.

Right answer is (d) YAC (Yeast Artificial Chromosomes)

For explanation: Both BAC (Bacterial Artificial Chromosomes) and YAC (Yeast Artificial Chromosomes) ACT as a suitable vector for the process of cloning in HGP WHEREAS BACTERIA and yeast act as the HOST for cloning in HGP.

Correct option is (c) Bacteria

For explanation I would say: Bacteria and yeast are the most COMMONLY used hosts for the process of cloning in Human Genome PROJECT. Not all types of FUNGI can be used for this process. But yeast and BACTERIUM can be employed.

Correct ANSWER is (b) Expressed Sequence Tags

To explain: The methodologies for the HGP are INVOLVED in two major processes. ONE among them is ESTs (Expressed Sequence Tags). It is USED to identify all the genes that are expressed as RNA in HGP.

The correct OPTION is (d) Negative REGULATION

Easiest explanation: The regulation of a LAC operon by the repressor is known as negative regulation. At rare occasions, lac OPERONS are ALSO observed to be under the control of positive regulation. In negative regulation, the operon cannot transcribe the RNA polymerase enzyme.

The correct OPTION is (a) Lactose

For explanation I would say: The substrate for the enzyme β-galactosidase is lactose. The lac operon can EITHER be in its SWITCHED on or off position. This OPERATION is being regulated by lactose which is also known as the inducer.

Correct option is (c) Three

Easiest EXPLANATION: A lac OPERON consists of one regulatory gene (i) and three structural GENES (z, y and a). The “i” in regulatory gene is DERIVED from the word “inhibitor”.

Correct ANSWER is (C) Permease

Explanation: The structural gene (z) of the lac operon codes for β-galactosidase. It is RESPONSIBLE for the hydrolysis of polysaccharides. The ‘y’ genes CODE for permease. It increases the permeability of a CELL to β-galactosidase. The ‘a’ genes code for transacetylase.

The correct answer is (B) Lac operon

The BEST I can explain: Lac (lactose) operon has a polycistronic STRUCTURAL gene which is regulated by a common promoter and regulatory gene. It is MAINLY present in prokaryotes like bacteria. This TYPE of an arrangement is called as an operon in general.

Correct ANSWER is (b) Translation of the central dogma of DNA

For explanation: The central dogma of DNA occurs in its 2 STAGES. They are TRANSCRIPTION and translation. When the small subunit of the ribosome encounters an mRNA, the PROCESS of translation commences. The process of translation from the mRNA to the proteins occur.

Correct option is (a) True

Easiest explanation: The regulatory PROTEINS have the ability to act both as an ACTIVATOR and a repressor. They will be positive when they are ACTIVATORS. They will be negative when they are REPRESSORS.

The correct answer is (c) Reverse TRANSCRIPTIONAL level

The EXPLANATION: In eukaryotes, the REGULATION of gene expression occurs at various LEVELS. They are transcriptional level, processing level, transport of mRNA from the NUCLEUS to the cytoplasm and translational level.

Right choice is (d) Ribosomes

The explanation is: Lysosomes help in the BREAK down and digestion of the worn out or dead cell components. Mitochondria is known as the power house of the cell for the production of ATP MOLECULES. Nucleus helps in CARRYING the information from one GENERATION to the next generation. Ribosomes help in the SYNTHESIS of proteins.

Correct answer is (c) 80

The explanation: Ribosomes consists of structural RNAS and they also POSSESS about 80 different TYPES of PROTEINS in them. A RIBOSOME can either be in its active state or inactive state. While it is in its inactive state, it will exist as 2 subunits.

Right choice is (a) Charging of tRNA

To explain: In order to FORM a peptide BOND, a certain quantity of energy is required. The first phase in this process is known as charging of tRNA. It is also known as Aminoacylation of tRNA. In this process, the amino ACIDS are activated in the presence of ATP and are linked to their cognate tRNA.

The correct choice is (b) Translation

For explanation I would say: There are certain sequences for the bases PRESENT in the mRNA. The order and sequence of the AMINO acids are defined by them. And so, transcription is a PROCESS where the POLYMERISATION of the polypeptide leads to the formation of amino acids.

The CORRECT answer is (B) Bases that are complementary to the code

For explanation I would say: The stop codons are UAA, UAG and UGA. These codons are absent in the tRNA molecules. tRNA POSSESSES an AMINO acid acceptor end which is the site for binding the amino acids. FINALLY, the anticodon loop of the tRNA contains bases that are complementary to the codes.

Correct CHOICE is (d) TRNA

Best explanation: The tRNA was known by the name sRNA in its early DAYS. sRNA stands for soluble RNA. This was even before the postulation of the genetic code.But, the role of tRNA as an ADAPTER was assigned much later.

Correct answer is (b) FRANCIS Crick

The explanation is: Amino acids do not have any structural specialties to read a CODE. Francis Crick came up with an IDEOLOGY that an adapter molecule will be PRESENT. This adapter molecule will be capable of both reading the code and ALSO on binding itself to the specific amino acid.

The correct OPTION is (a) True

For EXPLANATION I would say: In the earlier days, Francis Crick FELT that a mechanism has to be there to read the codes. This was because amino acids possess no structural specialities to do that. And so, he POSTULATED that there had to be an ADAPTER molecule.

The correct choice is (B) When it codes for 1 amino acids

Explanation: One codon codes for only one amino acid. And so, the CODING is said to be unambiguous and specific. In some cases, one amino acid is coded more than once by MANY codons. These are CALLED are degenerates.

Correct option is (d) 61

Explanation: There are a total of 64 codons. Among these 64 codons, 61 codons are responsible for CODING the amino acids. The remaining 3 codons do not take PART in producing the amino acids. On the other hand, they are responsible for stopping the PRODUCTION of amino acids. Hence, they are CALLED as “STOP Codons”.

Correct answer is (d) 4

For explanation I would SAY: George GAMOW who was a physicist mentioned that to be able to CODE for 20 amino acids, we require 4 bases. The code should also be MADE up of 3 NUCLEOTIDES. The code should be made up of bases in a particular combination.

Correct ANSWER is (b) Genetic CODE

The explanation: The change in NUCLEIC acids is responsible for the change in AMINO acids in the protein. This observation LED to the proposition of genetic code. Genetic code is responsible for directing the sequence of amino acids during protein synthesis.

Right ANSWER is (b) 200-300

For explanation I WOULD say: During the additional process of tailing that is undergone by the hnRNA, adenylate RESIDUES are added to it. An approximate count of 200-300 adenylate residues are added to it at the 3’-end of the hnRNA.

The correct OPTION is (a) Splicing

To elaborate: The ancient FEATURE of a genome is represented by its split-gene ARRANGEMENTS. The presence of introns is a reminiscent of its antiquity. And so, the PROCESS of splicing gives a representation about the DOMINATION of the world of RNA (RNA-world).

The correct CHOICE is (d) SPLICING

Explanation: The primary TRANSCRIPT CONSISTS of both the exons and the introns, and they are non-functional. And so, the introns are removed and the exons are ARRANGED in a well-defined manner. This process is called as splicing.

The CORRECT option is (b) Elongation

For EXPLANATION I would say: There are three stages in the transcription process. They are initiation, elongation and termination. Among these three, the stage of elongation is catalyzed by the RNA POLYMERASE ENZYME.

The correct choice is (c) RNA polymerase

The explanation is: The RNA polymerase BINDS to the promoter REGION of the DNA molecule. After the attachment of the RNA polymerase enzyme to the promoter, the process of transcription is being INITIATED.

Right ANSWER is (b) It brings the AMINO ACIDS and reads the genetic code

The explanation is: The role of mRNA is to PROVIDE the template strand. The role of TRNA is to bring the amino acids and read the genetic code. rRNA plays the structural and catalytic role during the process of translation.

Right option is (c) A segment of DNA CODING for polypeptides

For explanation I WOULD say: A CISTRON is the segment of a DNA. It is responsible for coding polypeptide chains. This is seen during the process of protein SYNTHESIS.

Right option is (b) Eukaryotes

The best I can explain: Cistrons are the segments of the DNA HELICAL STRUCTURE which code for polypeptide chains. The structural gene in the transcription UNIT can be either monocistronic or POLYCISTRONIC. The monocistronic genes are mostly present in eukaryotes.