Which free-living cells were the earliest contributors to the formation of Earth's oxidizing atmosphere?
a) chloroplasts
b) mitochondria
c) endosymbionts
d) seaweeds
e) cyanobacteria
Answer: e) cyanobacteria
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Air flow in a microbiology laboratory should be:
a. from lower to higher risk areas. b. minimized as much as possible. c. optimized to prevent the settling of dan-gerous aerosols. d. well-filtered by recirculating it through numerous filters before recycling.
In RNA, uracil is present instead of the thymine in DNA
Indicate whether the statement is true or false
Which of the following terms accurately describes the replication of DNA in vivo?
A) dispersive B) conservative C) semidiscontinuous D) continuous E) nonlinear
Which of the following statements about hair cells is not true?
A. Their structure includes stereocilia and a kinocilium. B. Bending of the cells triggers ion flow across the cell membrane. C. They are found in the mammalian ear. D. They are found in the fish lateral line system. E. They can be repaired if they rupture.