Exam 22: The Origin and History of Life

The age of a fossil can be estimated by analyzing the decay of radioisotopes within the accompanying rock. If you suspected a fossil was 100 million years old, which type of radioisotopes would you use to analyze the accompanying rock?

You have just invented a time machine and you want to investigate the past (the dream of every paleontologist!). When is the earliest time in Earth history that you could go back and not have to have an oxygen tank so that you could breathe normally?

When lipids, phosphates, carbohydrates and RNA were placed on clay, a lysosome was formed. Why was the clay an important surface for lysosome formation and how is RNA associated with the lysosome?

Which of the following are thought to have occurred because of the increase of oxygen (O₂) in the atmosphere during and after the Silurian Period?

Because hardly any oxygen (O₂) was in the early Earth's atmosphere, the single-celled microorganisms probably used which of the following to produce energy to drive metabolic processes?

A protobiont

John Bernal suggested that prebiotic synthesis of polymers took place on clay because

To explain the origin of the nuclear genome, which of the following hypotheses are most widely accepted?

Which of the following would likely fossilize under normal environmental conditions?

The origin of the mitochondrion and chloroplast by endosymbiosis, hypothesizes that these organelles originated by

In eukaryotes, genes involved in transcription and translation are derived from

Which would be most likely to be fossilized?

The first known fossils of living cells were preserved in rocks that are 3.5 billion years old, but scientists postulated that the first cells arose many millions of years prior to this time. These first cells were most likely ...

The deep-sea vent hypothesis for the formation of prebiotic organic molecules is based on

In 1909, Charles Walcott discovered fossils in the Burgess Shale of the Canadian Rockies. The area was formed by an underwater mudslide that provided an oxygen free environment, so decomposition was minimal. Why were these fossils so unique?

Both DNA and RNA can store information, yet DNA is the major information storage molecule in most cells. What are the advantages of using DNA for information storage instead of RNA?

The event called the Cambrian Explosion resulted in an abrupt increase in

A scientist found an unweathered igneous rock that contained .025 g of potassium-40 and 075 g of argon-40. The half-life of potassium-40 is 1.3 billion years. The rock would be estimated to be

The major difference between the endosymbiotic relationship theory and the symbiotic relationship theory is

At the end of the Permian period a large mass extinction occurred; 90-95% of the marine and terrestrial species were eliminated. Which of the following are thought to be the possible cause(s) of this mass extinction?