Molecular Basis of Inheritance MCQs for NEET — Botany Questions with Answers

An operon is a functioning unit of genomic DNA that contains a cluster of genes under the control of a single promoter. It contains a regulator gene, promoter gene, operator gene, and structural genes. The regulator gene produces a repressor protein that can bind to the operator region to control the transcription of the structural genes.

E. coli produces β-galactosidase, thiogalactoside transacetylase, and lactose permease during lactose catabolism. Lactose dehydrogenase is not involved in this process. Thus, option o3 is the correct answer.

The Human Genome Project (HGP) is not an Indian scientific research project. It was an international research project with the aim of mapping all the genes of the human genome. Thus, option o1 is the correct answer as it is the incorrect statement.

Humans have approximately 50 times more genes than E. coli. E. coli has about 4,000 genes, while humans have around 20,000-25,000 genes. Thus, option o4 is the correct answer.

1. Ligase: Joins short segments of DNA together, which is correct.
2. Helicase: Breaks the hydrogen bonds between complementary pairs during DNA replication, which is also correct.
3. DNA Polymerase: It synthesizes DNA molecules from nucleotides, not cuts DNA at specific sequences.
4. Gyrase: It relieves the strain while double-strand DNA is being unwound by helicase, not joins weak hydrogen bonds.

In eukaryotes, DNA replication is bidirectional and has multiple origins of replication. This allows the large quantity of DNA to be replicated quickly and accurately.

Eukaryotes typically have Okazaki fragments that are 100 to 200 nucleotides long, whereas fragments in prokaryotic E. coli can be 2,000 nucleotides long. The reason for this discrepancy is unknown. Each eukaryotic chromosome is composed of many replicating units of DNA with multiple origins of replication.

RNA-dependent DNA polymerase, also known as reverse transcriptase, is the enzyme that synthesizes DNA from an RNA template. This process involves the formation of phosphodiester bonds.

chargaffs rule of complementarity of bases