TLS Online TPP Program

#Question id: 4264


A classic biochemical experiment nicely illustrated the point that the ribosome recognizes tRNA and not the amino acid that it is carrying. In that following observation were made. Which of them can be correct.

A. The cysteine attached to cysteine-tRNACys can be converted to an alanine by chemical reduction to give alanine-tRNACys.

B. Alanine-tRNACys introduces alanines at codons that specify insertion of cysteine.

C. Different mechanism is used to incorporate selenocyteine on tRNA as selenocysteine is incorporated into proteins by chemical modification after translation

D. Selenocysteine is generated enzymatically from serine carried on a special tRNA that is charged by serine-tRNA synthetase

E. Above examples can conclude that the translation machinery relies on the high fidelity of the aminoacyl-tRNA synthetases to ensure the accurate decoding of each mRNA

#Unit 3. Fundamental Processes
  1. A, B, & E only   

  2. A, B, C, D, & E

  3. A, B, D, & E only

  4. A, D, & E only

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TLS Online TPP Program

#Question id: 33481

#Unit 2. Cellular Organization

A. In homologous introns, the pattern of divergence involves both changes in length.
B. Divergence in introns is due to deletions and insertions and base substitutions. 
C. Introns are slowly evolve while exons much more rapidly 
D. When a gene is compared among different species, there are instances where its exons are homologous but its introns have diverged so much that very little homology is retained.

TLS Online TPP Program

#Question id: 33482

#Unit 2. Cellular Organization

Find true and false statements
A. In general, mutations occur at the same rate in both exons and introns, 
B. Exon mutations are eliminated more effectively by selection.
C. Introns may more freely accumulate point substitutions and other changes.

TLS Online TPP Program

#Question id: 33483

#Unit 2. Cellular Organization

Which of the following is correct
A. A set of homologous genes should share common features that preceded their evolutionary separation.
B. All globin genes have a common form of organization with four exons and one introns.
C. A gene family is defined as a group of genes that encode related or identical products as a result of gene-duplication events.

TLS Online TPP Program

#Question id: 33484

#Unit 2. Cellular Organization

When a complete gene is found within the intron of a larger “host” gene called as

TLS Online TPP Program

#Question id: 33485

#Unit 2. Cellular Organization

Most genes are uninterrupted in yeast, but most genes are interrupted in flies and mammals. Uninterrupted genes have

TLS Online TPP Program

#Question id: 33486

#Unit 2. Cellular Organization

Only a few genes have uninterrupted coding sequences in case of mammals. How much % of genes in mammals are uninterrupted