An 11-year-old male was having difficulty reading the graphs that his teacher was showing at the front of classroom. His teacher recommended he be seen by an ophthalmologist. Not only was he asked to look at a Snellen letter chart for visual acuity but he was also asked to identify numbers in an Ishihara chart. He responded that he merely saw a bunch of dots. Abnormal color vision is 20 times more  common in men than women because most cases are caused by an abnormal

#Question id: 4948

#Unit 9. Evolution & Diversity of Life Forms

RNA molecules can both carry genetic information and be catalytic. This supports the proposal that 

#Question id: 4949

#Unit 9. Evolution & Diversity of Life Forms

What probably accounts for the switch to DNA-based genetic systems during the evolution of life on Earth?

#Question id: 4951

#Unit 9. Evolution & Diversity of Life Forms

The synthesis of new DNA requires the prior existence of oligonucleotides to serve as primers. On Earth, these primers are small RNA molecules. This latter observation is evidence in support of the hypothesized existence of

#Question id: 4952

#Unit 9. Evolution & Diversity of Life Forms

Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. Which of these questions is currently the most problematic and would have the greatest impact on our understanding if we were able to answer it?

#Question id: 4953

#Unit 9. Evolution & Diversity of Life Forms

Several scientific laboratories across the globe are involved in research concerning the origin of life on Earth. Which graph below, if the results were produced abiotically, would have the greatest promise for revealing important information about the origin or Earthʹs first genetic system?

#Question id: 4954

#Unit 9. Evolution & Diversity of Life Forms

If natural selection in a particular environment favored genetic systems that permitted the production of daughter ʺcellsʺ that were genetically dissimilar from the mother ʺcells,ʺ then one should expect selection for

I. polynucleotide polymerase with low mismatch error rates.

II. polynucleotide polymerases without proofreading capability.

III. batteries of efficient polynucleotide repair enzymes.

IV. polynucleotide polymerases with proofreading capability.

V. polynucleotide polymerases with high mismatch error rates.