The experiments by miller and urey | Quick Homework Help
1. The experiments by Miller and Urey, in which methane, ammonia, hydrogen gases were placed in a closed chamber with circulating water vapor and electricity, generated:
Answer
a.primitive living cells.
b.fully formed RNA molecules.
c.amino acids and nucleotide precursors.
d.protocells.
2. Why is RNA thought to have been the primitive carrier of hereditary information rather than DNA?
Answer
a.RNA is chemically simpler than DNA.
b.RNA can to some extent function as an enzyme, assisting the replication process.
c.The copying of genetic information is more reliable in RNA replication than in DNA replication.
d.There is ample evidence of RNA molecules in fossil dinosaurs, pre-dating DNA.
3. It is thought that RNA evolved before DNA because:
Answer
a.RNA is more complex than DNA.
b.RNA can act as genetic material and as an enzyme.
c.RNA is easier to synthesize.
d.RNA is more common in living systems than DNA.
4. From what types of ancestors are mitochondria and chloroplasts derived?
Answer
a.Mitochondria from protobacteria related to present-day Rickettsiales, chloroplasts from a cyanobacterium.
b.Mitochondria from a primitive archaea, chloroplasts from a primitive green alga.
c.Mitochondria from a primitive archaea, chloroplasts from a cyanobacterium.
d.Mitochondria from protobacteria related to present-day Rickettsiales, chloroplasts from a primitive green alga.
5. All of the following are true regarding the genetic code except
Answer
a.The genetic code suggests that all living forms descended from a single common ancestor.
b.The genetic code is essentially universal among living things on earth.
c.The genetic code suggests that life originated only once on the Earth.
d.The DNA-based genetic code allowed for the evolution of large genomes.
6. The evolution of chromosomes was advantageous for life because:
Answer
a.the replication and segregation of chromosomes reduced genomic conflict between genes.
b.they were more complex than RNA.
c.chromosomes mutated easily, providing more variation.
d.linked genes are more stable.
7. Multicellularity may have evolved to:
Answer
a.encourage cells to include non-cooperators and promote cheating.
b.protect the organism from predators by becoming too large to consume.
c.promote genomic conflicts between cells.
d.All of the above reasons help explain the origin of multicellularity.
8. The maintenance of differentiated cells of a multicellular organism through cycles of cell division requires:
Answer
a.both a mechanism for genetic regulation and sexual reproduction.
b.a form of genetic memory that promotes genetic conflict.
c.both a mechanism for genetic regulation and a genetic memory.
d.chromosomes.
9. The cooperation between different levels such as chromosomes and cells is explained by:
Answer
a.epigenetic inheritance.
b.kin selection.
c.aIDing the fitness of the various levels.
d.the evolution of the genome.
10. Why is cooperation between related individuals easier to understand than cooperation between unrelated individuals?
Answer
a.Because of their relatedness the individuals involved tend to have a more similar tendency to cooperate.
b.Relatives know each other better on average than unrelated individuals, therefore there is less uncertainty about each other’s reliability.
c. If you help a relative to increases its reproductive success, you also enhance your own fitness, because some of the genes in your relative are identical to your own.
d.None of the above.
11. What is the most likely reason why natural selection has produced reproductive systems in which offspring start developing from a single cell?
Answer
a.To minimize the inheritance of mutations.
b.To minimize potential conflicts between genetically different parts of the organism.
c.To maximize the potential number of offspring.
d.To maximize the efficacy of selective screening of offspring quality.
12. What is the mosaic history of a species?
Answer
a.The mosaic history is the history of the origin of life from recycled stars.
b.The mosaic history is the combined adaptations found in a species.
c.The mosaic history describes the different times when various parts of a species originated.
d.The mosaic history is the evolution of interactions between species.
13. The mountain ranges, oceanic trenches, and other features of the Earth are the result of:
Answer
a.continental drift.
b.meteorite impacts.
c.volcanic eruptions.
d.the toxic, hot, and sulphurous atmosphere.
14. Island chains, such as the Hawaiian archipelago, were formed by:
Answer
a.the simultaneous eruptions of several volcanoes.
b.hot spots that constructed islands on plates that drift over them.
c.the collision of plates.
d.the erosion of the land formerly between the islands.
15. Which one of the following statements concerning continental glaciers is not true?
Answer
a.Continental glaciers contributed to the distribution of many species.
b.Continental glaciers were involved with the formation of continental connections.
c.Continental glaciers contributed to changing sea levels.
d.Continental glaciers led to the extinction of the dinosaurs.
16. Which one of the following was the most catastrophic or greatest mass extinction?
Answer
a.Ordovician extinction.
b.Permian extinction.
c.Cretaceous extinction.
d.Pleistocene extinction.
17. Which one of the following is an example of how life has modified the Earth?
Answer
a.Bacteria formed the large deposits of copper and zinc.
b.Photosynthesis put the carbon dioxide in the atmosphere.
c.Goats and sheep grazing changed deserts into woodlands.
d.All of the above are examples of how life has changed the Earth.
18. All of the following features of the Earth are important to life as we know it, except?
Answer
Abundant surface water in liquid state.
A rich supply of water-soluble ions and simple compounds.
Free hydrogen in the atmosphere.
The existence of an atmosphere.
19. Which of the following was not likely a consequence of continental glaciation?
Answer
a.Areas that are now islands were connected to continents.
b.Ocean levels dropped exposing large regions of continental shelf.
c.Volcanoes erupted more frequently because of the weight of the ice pressing on the Earth’s crust.
d.Terrestrial organisms at high latitudes had to move towards the equator or go extinct.
20. What are two of the major contributions bacteria have made to the planet on a geological scale?
Answer
a.Oxygen in the atmosphere and much of the ore deposits of the planet.
b.Disease and soil.
c.River deltas and clean water.
d.Carbon dioxide and hydrogen in the atmosphere.
