Biol 322 Exam 4 (ch. 11-15, 18, 19, 20)
Among the oldest fossils on Earth are the microfossils from the Agnes gold mines of
South Africa, which are ______ years old - answer3.2 billion
In order to understand the origin of life on Earth, evolutionary biologists collaborate with:
- answerAll of the above (chemists, geologists, atmosphere scientists)
Which of the following statements about LUCA is NOT correct? - answerIt is meant to
be a single organism
Which two scientists elaborated on Darwin's idea of the "warm little pond" and
formulated the "prebiotic soup hypothesis" as the first hypothesis for the abiotic origin of
life on earth? - answerOparin and Haldane
Which gas was most likely the least abundant in early Earth's atmosphere? -
answeroxygen
Miller and Urey developed and conducted some experimental tests for a "prebiotic
soup" model of the origin of life, which had been proposed a few decades earlier by
Oparin and Haldane. What did Miller and Urey show could be synthesized abiotically? -
answeramino acids
In 1977 Sidney Fox tried a different approach to testing the prebiotic synthesis of
biological molecules. He mixed a number of different amino acids together at a high
temperature (120 C) in an environment lacking water. When he subsequently placed the
mixture into water to investigate what the amino acids would form he: - answerfound
some peptide-like structures, but the bonds between the amino acids were weak and
unstable
The first genetic material was most likely: - answerRNA
All of the following is true regarding Spiegelman's experiment on the origins of life
EXCEPT that: - answerthere was no selection for any of the variations in length
Which of the following statements about the Lincoln and Joyce experiment on self-
replicating ribozymes is most likely correct? - answerThe self-replicating ribozymes that
had more efficient catalytic activities would soon began to dominate their populations
What is the most relevant hypothesis for the benefit of making the switch from the RNA-
to a DNA-based genetic system during the evolution of life? - answerDNA is a more
stable molecule because deoxyribose is less reactive than is ribose
, The origin of cell structures might be hypothesized to have involved a hypercycle, based
on mutualism at the molecular level. Which of the following is correct regarding the
hypercycle model? - answerNatural selection will favor a hypercycle that is enclosed in
a membrane
Which of the following molecules involved in membrane structure was likely favored by
selection in the evolution of early cells? - answerfatty acids
What do we know about horizontal gene transfer (HGT) in the evolution of early life? -
answerHGT was probably a powerful force during early cell evolution, leading to
complex cellular organisms
In light of recent achievements in the field of genomics, would it be reasonable to expect
that the use of comparative genomics might shed light on the extinct genomes of early
life? - answerComparative genomics and studies of the bacteria with very small
genomes do shed light on a common ancestor and researchers can estimate the
minimal characteristics that a cell would need to operate as a living organism
The human parasite Mycoplasma genitalium, withone of the smallest genomes of any
organism that can be grown, as well as Chlamydia trachomatis, an obligate intracellular
parasite, are examples of the type of organisms that functional genomics researchers
have focused on. What is the main purpose of the study of such genomes. - answerBy
studying such genomes, researchers try to discover the basic and essential cellular
functions of early life
Slime molds are unusual eukaryotes. They spend most of their life cycle as single-celled
organisms and yet, under certain conditions, they form a slug-like multicellular stage
and then a fruiting body composed of both somatic cells and reproductive spores. The
best known species of slime mold is a soil dweller, Dictyostelium discoideum. Why is it
important to study this and related species of slime molds? - answerSlime molds
provide hints as to how multicellularity may have evolved.
Which of the following statements regarding complexity of living organisms is NOT
correct? - answerNatural selection necessarily entails an increase of complexity over
evolutionary time
Which of the following is not a major transition in the evolution of life, based on Maynard
Smith and Szathmary (1997)? - answerthe formation of the solar system including Earth
Which of the following examples would be the best match for the statement?
"individuals give up the ability to reproduce independently, and they join together to form
a larger grouping that shares reproduction." - answerSolitary individuals started living
together in colonial groups, sometimes even giving up the possibility of independent
replication, as we see in many species of social insects.
Among the oldest fossils on Earth are the microfossils from the Agnes gold mines of
South Africa, which are ______ years old - answer3.2 billion
In order to understand the origin of life on Earth, evolutionary biologists collaborate with:
- answerAll of the above (chemists, geologists, atmosphere scientists)
Which of the following statements about LUCA is NOT correct? - answerIt is meant to
be a single organism
Which two scientists elaborated on Darwin's idea of the "warm little pond" and
formulated the "prebiotic soup hypothesis" as the first hypothesis for the abiotic origin of
life on earth? - answerOparin and Haldane
Which gas was most likely the least abundant in early Earth's atmosphere? -
answeroxygen
Miller and Urey developed and conducted some experimental tests for a "prebiotic
soup" model of the origin of life, which had been proposed a few decades earlier by
Oparin and Haldane. What did Miller and Urey show could be synthesized abiotically? -
answeramino acids
In 1977 Sidney Fox tried a different approach to testing the prebiotic synthesis of
biological molecules. He mixed a number of different amino acids together at a high
temperature (120 C) in an environment lacking water. When he subsequently placed the
mixture into water to investigate what the amino acids would form he: - answerfound
some peptide-like structures, but the bonds between the amino acids were weak and
unstable
The first genetic material was most likely: - answerRNA
All of the following is true regarding Spiegelman's experiment on the origins of life
EXCEPT that: - answerthere was no selection for any of the variations in length
Which of the following statements about the Lincoln and Joyce experiment on self-
replicating ribozymes is most likely correct? - answerThe self-replicating ribozymes that
had more efficient catalytic activities would soon began to dominate their populations
What is the most relevant hypothesis for the benefit of making the switch from the RNA-
to a DNA-based genetic system during the evolution of life? - answerDNA is a more
stable molecule because deoxyribose is less reactive than is ribose
, The origin of cell structures might be hypothesized to have involved a hypercycle, based
on mutualism at the molecular level. Which of the following is correct regarding the
hypercycle model? - answerNatural selection will favor a hypercycle that is enclosed in
a membrane
Which of the following molecules involved in membrane structure was likely favored by
selection in the evolution of early cells? - answerfatty acids
What do we know about horizontal gene transfer (HGT) in the evolution of early life? -
answerHGT was probably a powerful force during early cell evolution, leading to
complex cellular organisms
In light of recent achievements in the field of genomics, would it be reasonable to expect
that the use of comparative genomics might shed light on the extinct genomes of early
life? - answerComparative genomics and studies of the bacteria with very small
genomes do shed light on a common ancestor and researchers can estimate the
minimal characteristics that a cell would need to operate as a living organism
The human parasite Mycoplasma genitalium, withone of the smallest genomes of any
organism that can be grown, as well as Chlamydia trachomatis, an obligate intracellular
parasite, are examples of the type of organisms that functional genomics researchers
have focused on. What is the main purpose of the study of such genomes. - answerBy
studying such genomes, researchers try to discover the basic and essential cellular
functions of early life
Slime molds are unusual eukaryotes. They spend most of their life cycle as single-celled
organisms and yet, under certain conditions, they form a slug-like multicellular stage
and then a fruiting body composed of both somatic cells and reproductive spores. The
best known species of slime mold is a soil dweller, Dictyostelium discoideum. Why is it
important to study this and related species of slime molds? - answerSlime molds
provide hints as to how multicellularity may have evolved.
Which of the following statements regarding complexity of living organisms is NOT
correct? - answerNatural selection necessarily entails an increase of complexity over
evolutionary time
Which of the following is not a major transition in the evolution of life, based on Maynard
Smith and Szathmary (1997)? - answerthe formation of the solar system including Earth
Which of the following examples would be the best match for the statement?
"individuals give up the ability to reproduce independently, and they join together to form
a larger grouping that shares reproduction." - answerSolitary individuals started living
together in colonial groups, sometimes even giving up the possibility of independent
replication, as we see in many species of social insects.
