The most severe mass extinction on Earth occurred at the end of the ____ period
a. Cambrian
b. Carboniferous
c. Jurassic
d. Permian
e. Devonian
ANSWER: d
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Horses and donkeys can interbreed, but their offspring (mules) are infertile. This is an example of what kind of reproductive isolating mechanism?
A. pre-zygotic, behavioral isolation B. pre-zygotic, temporal separation C. pre-zygotic, ecological separation D. post-zygotic E. post-zygotic, ecological separation
The chromosome in bacteria and archaea
A. forms a single linear strand of DNA. B. contains all the cell's plasmids. C. is located in the cell membrane. D. is part of the nucleoid.
A mechanism of gene regulation that controls the amount of mRNA available for translation is called
____________________. Fill in the blank(s) with the appropriate word(s).
During cell division, it is essential that the genetic material be distributed equally to the two daughter cells. This is accomplished through the participation of which one of the following organelles?
A) centrioles B) ribosomes C) peroxisomes D) Golgi apparatus E) nucleolus