All questions of Molecular Basis of Inheritance for NEET Exam

Ribosomes are site of protein synthesis and are known as protein factory

Since The stop codons are UAA, UAG, and UGA.  They encode no amino acid. The ribosome pauses and falls off the mRNA.

Chromosomes are thread like structures of DNA and proteins that carry genetic information of organisms in the form of genes. The human chromosomes with least number of genes is Your chromosome.
Option " C " is correct answer.

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Bacteria can take up forigen DNA in a process called transformation. It occurs after restriction digest and ligation and transfers newly made plasmid to bacteria.
Bacteria with a plasmid are antibiotic resistant, and each will form a colony.

The hybridization of probes having radioactive isotopes with various sequence of nitrogen bases with ssVNTR is called southern blotting. Southern blotting is a laboratory technique used to detect a specific DNA sequence in a blood or tissue sample. A restriction enzyme is used to cut a sample of DNA into fragments that are separated using gel electrophoresis. The DNA fragments are transferred out of the gel to the surface of a membrane. The membrane is exposed to a DNA probe labeled with a radioactive or chemical tag. If the probe binds to the membrane, then the probe sequence is present in the sample. Hence, the correct answer is option 'B'.

B is correct refer to ncert for details

AAA for lysine AUG for methionine UUA for leucine CCC for proline. here only A option is correct . Only A is correctly matched .

It is possible to extract DNA from WBC, a root hair cell but not from body secretion ex sweat.

A is helicase, it unwind the DNA and B is SSB protien or single strand bonding protien it prevent the strands of DNA from sticking together again so that the replication can be made forward

Gel electrophoresis is a technique used to separate DNA fragments according to their size. DNA fragments are loaded into well at one end of a gel, and an electric current is applied to pull them through the gel. DNA fragments are negatively charged, so they move towards the positive electrode. Small fragments move farther while large fragments comes closer

Ribozymes: Catalysts of Life
Ribozymes are unique RNA molecules capable of catalyzing biochemical reactions, a role traditionally associated with proteins. The formation of peptide bonds is one of the key reactions facilitated by ribozymes.
Understanding Peptide Bond Formation
- Translation Process: During protein synthesis, ribosomes play a crucial role in linking amino acids together to form proteins.
- Role of rRNA: Ribosomal RNA (rRNA), a component of ribosomes, acts as a ribozyme. It catalyzes the formation of peptide bonds between adjacent amino acids in the growing polypeptide chain.
Mechanism of Action
- Amino Acid Activation: Transfer RNA (tRNA) brings amino acids to the ribosome, where the ribozyme catalyzes the reaction.
- Peptide Bond Formation: The ribozyme facilitates the nucleophilic attack of the amino group of one amino acid on the carbonyl carbon of another, resulting in the formation of a covalent peptide bond.
Significance in Biology
- Evolutionary Perspective: The presence of ribozymes supports the RNA world hypothesis, suggesting that early life forms relied on RNA for both genetic information and catalysis.
- Diversity of Functions: Beyond peptide bond formation, ribozymes are involved in various biological processes, including self-splicing introns and RNA processing.
Conclusion
In summary, the formation of peptide bonds is a crucial biochemical reaction catalyzed by ribozymes, particularly the rRNA in ribosomes. This highlights the versatility of RNA in essential biological functions, underscoring its importance in the molecular machinery of life.

BAC = bacterial artificial chromosome
YAC= yeast artificial chromosome... refer ncert class 12 bio..

Ncert bhi padhnliya kro

DNA polymerases are enzymes that synthesize DNA molecules from deoxyribonucleotides, the building blocks of DNA. These enzymes are essential for DNA replication and usually work in pairs to create two identical DNA strands from a single original DNA molecule. During this process, DNA polymerase "reads" the existing DNA strands to create two new strands that match the existing ones.

In bacteria, RNA polymerase is only responsible for elongation. It associates transiently with initiation-factor (σ) and termination-factor (ρ) to catalyse initiation and termination. This specificity is controlled by the association with these factors.

Understanding Genetic Coding
To determine how many bases are required to code for 20 amino acids, we need to explore how genetic information is encoded in DNA.
Base Pairing in DNA
- DNA consists of four nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G).
- These bases pair in specific combinations: A with T, and C with G.
Coding for Amino Acids
- In the genetic code, amino acids are specified by sequences of bases known as codons.
- Each codon is made up of three nucleotide bases.
Calculating Codons
- Since one codon consists of three bases, the number of unique codons can be calculated using the formula 4^n, where n is the number of bases in the codon.
- For three bases (n=3):
- 4^3 = 64 possible codons.
Mapping Codons to Amino Acids
- Out of these 64 codons, 61 encode for the 20 standard amino acids.
- The redundancy in the genetic code allows for multiple codons to code for the same amino acid.
Conclusion
- Since each amino acid is represented by a combination of three bases (codons), the minimum requirement for coding 20 amino acids is indeed 3 bases.
- Thus, the correct answer to the question is option 'C' (3 bases).
This understanding emphasizes the intricate relationship between DNA structure and protein synthesis, crucial for biological processes.

D option is correct bcz protein is a polypeptide and it's a primary structure of protein