Practice Questions

TLS Online TPP Program

#Question id: 2887

Which of the following reasons has led to the evolutionary selection of an extra methyl group in DNA?

#Unit 2. Cellular Organization

Thymine is more stable than Uracil due to the absence of an extra methyl group attached to the 5’ position.
Cytosine undergoes spontaneous deamination to yield Uracil, which repair enzymes cannot recognize as foreign to DNA.
If the genetic material contained uracil, then uracil arising from cytosine deamination would go undetected by the surveillance systems that maintain the genome.
Uracil has greater resistance to photochemical mutation, making the genetic material more stable.

More Questions

TLS Online TPP Program

#Question id: 3324

#Unit 11. Evolution and Behavior

If only 20 males and 20 female grizzlies exist today, but only 10 of the males and 6 female breed, what are effective population size?

TLS Online TPP Program

#Question id: 12264

#Unit 10. Ecological Principles

You discover several species of unpalatable insects that closely resemble each other. You propose that this is an example of __________ mimicry.

TLS Online TPP Program

#Question id: 5756

#Unit 8. Inheritance Biology

Type of mutation caused by an addition or deletion of a base in a polypeptide-encoding part of a gene

TLS Online TPP Program

#Question id: 14983

#Unit 2. Cellular Organization

A network of intermediate filaments, called the nuclear lamina, lies against the inner surface of the envelope and supports it. Which structure usually is associated with the inner membrane

TLS Online TPP Program

#Question id: 20974

#Unit 12. Applied Biology

An example of biosensor, urea electrode makes use of which of the following electrodes?