Question

1) Give several pieces of evidence that RNA preceded proteins and DNA in living things. 2) Do your answers to (1) mean that the first life was RNA-based, with RNA serving as both the catalyst and the genetic material? Briefly discuss the strengths and weaknesses of this hypothesis. 3) It is believed that the machinery for photosynthesis evolved only once, in the cyanobacteria. However, several unrelated groups of eukaryotes, such as green plants, diatoms, and euglenoids, are able to photosynthesize. How can this be explained? 4) Answer each question True or False (T/F). If the answer is false, explain why. Eukaryotic cells are more similar to archaea for genes involved in protein synthesis and DNA replication, but more similar to bacteria for genes involved in metabolism. RNA has been found in meteorites, and was produced in the Miller-Urey experiment, giving evidence supporting the "RNA-first" hypothesis of the origin of life. The last universal common ancestor of all living things lived less than 2 billion years ago. The first living things required oxygen (O2). The 12C/13C ratio is higher in living things than in atmospheric CO2. 5) Which of the following is your closest relative? Your second closest? a) a fungus; b) a dinoflagellate; c) a pine tree; d) a choanoflagellate; e) a ciliate; f) an archaean 6) Why are marine organisms relatively common in the fossil record, but mountain-dwelling species relatively rare?

          1) Give several pieces of evidence that RNA preceded proteins and DNA in living things.
2) Do your answers to (1) mean that the first life was RNA-based, with RNA serving as both the catalyst
and the genetic material? Briefly discuss the strengths and weaknesses of this hypothesis.
3) It is believed that the machinery for photosynthesis evolved only once, in the cyanobacteria. However,
several unrelated groups of eukaryotes, such as green plants, diatoms, and euglenoids, are able to
photosynthesize. How can this be explained?
4) Answer each question True or False (T/F). If the answer is false, explain why.
Eukaryotic cells are more similar to archaea for genes involved in protein synthesis and DNA
replication, but more similar to bacteria for genes involved in metabolism.
RNA has been found in meteorites, and was produced in the Miller-Urey experiment, giving
evidence supporting the "RNA-first" hypothesis of the origin of life.
The last universal common ancestor of all living things lived less than 2 billion years ago.
The first living things required oxygen (O2).
The 12C/13C ratio is higher in living things than in atmospheric CO2.
5) Which of the following is your closest relative? Your second closest? a) a fungus; b) a dinoflagellate;
c) a pine tree; d) a choanoflagellate; e) a ciliate; f) an archaean
6) Why are marine organisms relatively common in the fossil record, but mountain-dwelling species
relatively rare?

1) Give several pieces of evidence that RNA preceded proteins and DNA in living things.
2) Do your answers to (1) mean that the first life was RNA-based, with RNA serving as both the catalyst
and the genetic material? Briefly discuss the strengths and weaknesses of this hypothesis.
3) It is believed that the machinery for photosynthesis evolved only once, in the cyanobacteria. However,
several unrelated groups of eukaryotes, such as green plants, diatoms, and euglenoids, are able to
photosynthesize. How can this be explained?
4) Answer each question True or False (T/F). If the answer is false, explain why.
Eukaryotic cells are more similar to archaea for genes involved in protein synthesis and DNA
replication, but more similar to bacteria for genes involved in metabolism.
RNA has been found in meteorites, and was produced in the Miller-Urey experiment, giving
evidence supporting the "RNA-first" hypothesis of the origin of life.
The last universal common ancestor of all living things lived less than 2 billion years ago.
The first living things required oxygen (O2).
The 12C/13C ratio is higher in living things than in atmospheric CO2.
5) Which of the following is your closest relative? Your second closest? a) a fungus; b) a dinoflagellate;
c) a pine tree; d) a choanoflagellate; e) a ciliate; f) an archaean
6) Why are marine organisms relatively common in the fossil record, but mountain-dwelling species
relatively rare?

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