Question

4. Telomerases... a) are RNA-containing enzymes involved in replicating the ends of linear chromosomes b) cause aging in cells c) are structures located at the ends of eukaryotic chromosomes d) are needed by bacteria to complete synthesis of their chromosome ends e) are needed by bacteria to supercoil DNA 5. DNA methylation a) Modifies bases of tRNA molecules, allowing wobble b) Alters the activity of DNA polymerase by affecting access to the DNA c) Is a modification of histone tails that changes the shape of chromatin d) Influences gene expression by reducing the binding of transcription factors to DNA e) Influences gene expression by affecting mRNA stability 6. The wobble hypothesis describes base pairing that results a) In mutations because of errors during replication b) In errors during transcription c) In errors during translation d) In a single tRNA being able to bind to more than one codon sequence e) In tRNA binding to overlapping codons

Answer 1

Answer for question number 4 : The correct option is A

Explanation : Telomerases are the ribonucleoprotein complexes containing a small RNA that serves as a template for addition of new six nucleotide repeats. Or Telomerase, the enzyme that synthesizes the telomere ends of linear chromosomes, is a specialized reverse transcriptase that contains an internal RNA template. Telomeres undergo cycles of shortening of the lagging strands due to the inability to complete synthesis.

Most normal cells lose telomerase activity with increasing age of the organism and repeated generations of the cell division. In other words, after certain number of divisions normal cells reaches the Hayflicks limit beyond which cells will no longer divide instead they die.