CSIR NET 2024 | Life Science: Fundamental Processes | 6 May

The human α-tropomyosin gene is alternatively spliced to produce several forms of α-tropomyosin mRNA in various cell types (Figure).
 
For all forms of the mRNA, the encoded protein sequence is the same for exons 1 and 10. Exons 2 and 3 are alternative exons used in different mRNAs, as are exons 7 and 8
 
Consider the following statements:
A) Exons 2 and 3 must have the same number of nucleotides.
B) Exons 2 and 3 must each contain an integral number of codons (that is, the number of nucleotides divided by 3 must be an integer).
C) Exons 2 and 3 must each contain a number of nucleotides that when divided by 3 leaves the same remainder (that is, 0, 1, or 2).

 
Which of the following statements about exons 2 and 3 is the most accurate?

A gene 'Z' has two promoters. One promoter (PI) is used when the cell is stimulated by a particular steroid hormone, while the second promoter (PII) is used when the steroid hormone is absent. The single mRNA from transcription using PII is much shorter than that of the single mRNA transcript generated when PI is used.
 
Which of the following out come is possible?

Under a given renaturing condition E. coli DNA reassociates with a Cot ½ of 4.0 and an unknown DNA sample with a Cot ½ of 283. The complexity of this unknown DNA will be

The λ cohesive ends are called the cos sites and they play distinct roles during the λ infection cycle.
A) They allow the linear DNA molecule that is injected into the cell to be circularized, which is a necessary prerequisite for insertion into the bacterial genome
B) The role of the cos sites is to act as recognition sequences for an endonuclease that cleaves the catenane at the cos sites, producing individual lambda genomes. This endonuclease, which is the product of gene A on the lambda DNA molecule, creates the single stranded sticky ends, and acts in conjunction with other proteins to package each λ genome into a phage head structure.
C) Cos site have origin of replication and promoters for early genes essential for regulation of lytic-lysogenic decision
 
Which of the following statement is true for λ phage cos sites?

Which of the following agents can inhibits eukaryotic protein synthesis?
 
A) Chloramphenicol
B) Cycloheximide
C) Erythromycin
D) Puromycin
E) Streptomycin
F) Tetracycline