Which gas was most likely not present in the Earth's early atmosphere?
a. Methane
b. Hydrogen
c. None of these choices
d. Oxygen
e. Ammonia
d
Biology & Microbiology
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Which of the following genetic processes may be most helpful in accounting for the Cambrian explosion?
A) binary fission B) mitosis C) random segregation D) gene duplication E) chromosomal condensation
Biology & Microbiology
The allele pool is the sum of all of the alleles in a population
Indicate whether the statement is true or false
Biology & Microbiology
Would a human clone have a bellybutton?
A) Yes B) No
Biology & Microbiology
Organisms that are radially symmetrical have ________ embryonic germ layers
A) two B) three C) four D) five E) six
Biology & Microbiology