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tama401
wrote...
4 years ago
I am studying for my exam on Wednesday and chapter 25 is giving me hard time.  Can anyone please help me on these?
 
1. Miller and Urey's experiments that attempted to recreate conditions on early Earth were significant because ___________. (Concept 25.1)
   
   Proved the endosymbiosis hypothesis.
   They produced the first protobionts.
   They showed how radiometric dating could be used to give the absolute ages of rocks and fossils.
   They showed that organic molecules such as amino acids could be produced from inorganic molecules.
   They showed how polymers could form spontaneously on a clay substrate.

 2. Why do some scientists believe that RNA, rather than DNA, was the first genetic material? (Concept 25.1)
   
   RNA can replicate more accurately than DNA.
   RNA could have evolved into DNA
   RNA has both information storage and catalytic properties
   All the protobionts on early Earth contained RNA.
   All of the above
   

 3. Radiometric dating ____________ (Concept 25.2)
   
   Allows us to determine an absolute, errorless date.
   Can be used to directly date fossils up to 3 billion years old.
   Relies on the fact that the daughter isotope decays to the parent isotope at a constant rate.
   Only works on rocks younger than 75,000years.
   Allows us to indirectly date fossils up to billions of years old based on minerals in surrounding layers

 4. How does continental drift affect living organisms? (Concept 25.4)
   
   It causes climate change which puts selective pressure on organisms.
   It causes changes in habitats as when large amounts of shallow marine habitat were lost in the formation of Pangaea.
   It may cause an increase or decrease in competition among different species.
   It happens so slowly that it does not affect living organisms.
   All of the following are correct: It causes climate change which puts selective pressure on organisms; It causes changes in habitats as when large amounts of shallow marine habitat were lost in the formation of Pangaea; It may cause an increase or decrease in competition among different species.
      
 5. Hox genes are thought to play an important role in the development of different morphologies because_____. (Concept 25.5)
   
   They provide positional information in the embryo.
   They affect the timing of reproductive development in the organism.
   They paved the way for the development of multicellular organisms
   Affect the expression of certain developmental genes in different parts of the body.
   They affect the timing of development in the embryo
 
6. Evolution works by _____. (Concept 25.6)
   
   Predicting the future.
   Constantly increasing complexity
   "Tinkering" with existing structures
   Converging on a particular phenotype
   Molding the environment to conform to the organisms living in it.
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wrote...
*
Posts: 16612
Credits: 5430
4 years ago
1. B
2. A
3. E
4. E
5. A
6. D (guessing)

Bio_man 8)
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topic author
anderson.b.sullivan
wrote...
4 years ago
1. C
2. E
3. E
4.C
5.A
6. E
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