QUIZ 10

A characteristic of all modern, living cells is ____. a. a semipermeable membrane keeping the internal environment of the cell separate from the external environment b. a requirement for the nucleic acids to be contained behind a nuclear membrane c. a method of converting protein changes into nucleic acids d. a mechanism of converting energy from the sun e. nucleic acids linked in a sequence to form multiple large macromolecule chains

a

Multicellularity is believed to have evolved multiple times on Earth. a. True b. False

a

What happens when phospholipids are placed in an aqueous solution? a. They spontaneously form bilayers. b. They disperse and form polar bonds with other organic molecules present in the solution. c. They repel one another. d. The hydrophobic tails force the phospholipids to form "beads" at the surface, much like what you see when vegetable oil is added to water. e. They move to the water's surface and form a single-layered membrane between the water and the atmosphere.

a

Animals that lack a body cavity to separate the gut from the muscles of the body wall are referred to as ____. a. pseudocoelomates b. acoelomates c. indeterminates d. coelomates e. mesenteries

b

In most eumetazoans, the nervous system is derived mainly from which embryonic cell layer? a. mesoglea b. ectoderm c. epiderm d. endoderm e. mesoderm

b

One function provided by cell membranes is ____. a. structural integrity b. protection from parasitic genetic information c. the free passage of materials into and out of the cell d. to counteract size restrictions e. the exclusion of nucleic acids

b

Proteins may have been the first information-storage molecules because they can self-replicate as well as catalyze reactions. a. True b. False

b

The continuously sparking electrodes in the apparatus used in the Miller-Urey experiment simulated ____. a. solar energy b. lightning strikes c. hydrothermal vents d. volcanic eruptions e. radioactivity

b

The development of multicellular organisms likely originated from ____. a. endosymbiotic eukaryotes b. colonies of unicellular organisms of the same species c. endocytosis of other cells followed by mitosis d. colonies of numerous species of cells e. cooperation between different species of cells

b

The evolution of life on Earth was made possible by ____. a. DNA b. natural selection that favors efficient reproduction of organisms c. organelles d. random mutations e. an environment that favors oxygen photosynthesizers

b

According to the endosymbiont hypothesis, ____. a. the endocytosized bacteria became dependent on the host cell b. most of the genes from the endocytosed bacteria moved to the nucleus c. most of the genes from the endocytosed bacteria moved to the nucleus, the host anaerobe became dependent upon the endocytosed bacteria, and the endocytosed bacteria became dependent on the host cell d. the host anaerobe became dependent upon the endocytosed bacteria e. all endocytosed bacteria were photosynthetic

c

Cells with ____ are able to harvest the greatest amount of energy from electrons. a. photosystems b. double membranes c. cytochromes d. nuclei e. chloroplasts

c

Why is the absence of atmospheric oxygen (O2) so important to the Oparin-Haldane hypothesis? a. Oxygen would have supported microorganisms that promote chemical decay. b. Oxygen would have caused multiple explosions, converting chemical energy into heat energy and rendering that energy unavailable for driving the synthesis of organic molecules. c. Oxygen is able to reverse reactions by removing electrons and hydrogen from organic molecules, thus destroying the first organic compounds as quickly as they developed. d. Oxygen is more reduced than hydrogen gas, methane, or ammonia. e. Oxygen is corrosive and thus would have degraded many of the metallic compounds on Earth's surface, releasing toxic gasses into the new atmosphere.

c

DNA is favored as the storage molecule of genetic information because it ____ than RNA. a. has greater chemical stability and can assemble into longer coding sequences b. can assemble into longer coding sequences c. has more nucleotides d. has greater chemical stability e. has more nucleotides and greater chemical stability

d

Differentiation of cells into specialized cell types ____. a. results in a colony organism b. occurred when distinct species began to cohabitate c. requires cell signals affecting gene replication d. requires cell signals affecting gene expression e. decreases survivability

d

Evidence for the endosymbiotic theory includes ____. a. fossils of prokaryotic cells in the process of endocytosing cyanobacteria b. endocytosed organelles observed to survive free in the environment c. rRNA sequences that are unique to prokaryotes, mitochondria, and chloroplasts d. endocytosed cells observed to survive in the cytoplasm of the host cell e. RNA in prokaryotes, mitochondria, and chloroplasts arranged in a single, circular genome

d

Organic macromolecules may have formed by ____. a. sequestration inside a semipermeable membrane b. addition of water to small organic subunits to facilitates enzymatic synthesis reactions c. increasing availability of inorganic compounds d. dehydration synthesis reactions that combined smaller subunits into larger molecules e. spontaneous aggregation of the different organic compounds in the atmosphere

d

Some scientists believe that RNA was the first information storage molecule because ____. a. RNA is a less stable molecule than DNA b. proteins are made of far more amino acid monomers (over 20) than RNA (4) c. amino acids cannot form peptide bonds without ribosomes to catalyze their formation d. RNA can be an enzymatic catalyst as well as an information storage molecule e. some viruses use RNA as their information storage molecule

d

The final step in the development of eukaryotic cells was likely ____. a. circularization of DNA b. formation of membrane-bound organelles c. duplication of function in the endosymbiont and host cell d. transfer of genes and function from the endosymbiont to the host cell e. ingestion of photosynthetic bacteria

d

Volcanic activity on early Earth was responsible for the release of ____. a. water vapor necessary to form the first oceans b. gases for the early atmosphere c. gases for the early atmosphere and oxygen for photosynthesis d. gases for the early atmosphere and water vapor necessary to form the first oceans e. oxygen for photosynthesis

d

Where did Earth's atmosphere originate? a. Earth's gravity trapped gases from passing comets, gases were released from the Earth itself as it cooled, and Earth's gravity trapped gases from the Earth itself. b. Earth's gravity trapped gases from Earth itself. c. Earth's gravity trapped gases from passing comets. d. Gases were released from Earth itself as it cooled Earth's gravity trapped gases from the Earth itself. e. Gases were released from Earth itself as it cooled.

d

Life today derives nearly all its energy from ____. a. geochemical activity b. hydrothermal vents c. radioactive decay d. glucose molecules e. the sun

e

What assumption is made by researchers when designing experiments to model how life may have arisen on Earth? a. The development of living cells from nonliving matter was very rapid. b. Conditions on Earth have not changed over time. c. Living organisms are composed of elements commonly found on Earth, but absent in the rest of the universe. d. The chemical reactions of living things are only possible inside living systems. e. Life arose on Earth from nonliving matter.

e

What led to the increase in oxygen levels in the atmosphere on primitive Earth? a. the first photosynthetic reactions b. photosynthetic pathways that stripped oxygen off of carbon dioxide and retained only the carbon in subsequent steps c. the use of glycolysis in cells d. the development of cellular respiration pathways in cells e. photosynthetic cells that used water and not H2S as a source of electrons

e

Which feature of Archaea is shared with Bacteria but not with Eukarya? a. the chemical structure of the cell walls b. the sequestration of DNA into a nucleus c. the common occurrence of introns d. the plasma membrane structure e. a genome comprised of a single, circular molecule of DNA

e