Which of the following components was NOT
a significant part of the earth's early
atmosphere?
a. carbon dioxide
b. water vapor
c. nitrogen gas
d. oxygen gas
e. hydrogen gas
D
Biology & Microbiology
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The cyclic nitrogenous base used in transcription, uracil, is a ________.
A. purine B. porphyrin C. protein D. pyrimidine
Biology & Microbiology
Individuals with ____________________ are extremely sensitive to sunlight and develop skin cancer at a rate 1000 times above normal
Fill in the blank(s) with correct word
Biology & Microbiology
What is a common feature of all organisms?
a. DNA in circular chromosomes c. nucleus b. organelles d. cell structure
Biology & Microbiology
An element has 8 protons, 9 neutrons, and 8 electrons. Its atomic number and atomic mass, respectively, are _________.
Fill in the blank(s) with the appropriate word(s).
Biology & Microbiology