In the CRISPR / Cas system of a particular bacterial cell, it is noted that there are six spacer regions. What does this suggest about the bacterial cell?
A. The cell has six CAS genes due to past infections by viruses.
B. The cell has been infected by six viruses in the past.
C. The cell has developed protection from six different viruses.
D. The cell has been infected by six viruses in the past and now has developed a level of protection against all of them.
Answer: D
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Predation arose in prokaryotic organisms, increasing the complexity of interactions among organisms through their ability to engulf particulate food
A. true B. false
Your alarm clock goes off once again, and it is 7 a.m. Which of the following events leads you to hit
the snooze button?
a. The number of alpha waves emitted by the brain increases. b. The number of theta waves emitted by the brain increases. c. The reticular formation sends stimuli to the cerebral cortex. d. The cortex of the cerebellum is stimulated. e. The limbic system is stimulated.
The three major roles of the human nervous system are
A. sensory integration, glandular response, and motor response. B. seeing, feeling, and hearing. C. sensory input, sensory integration, and motor response. D. smooth muscle response, cardiac muscle response, and skeletal muscle response. E. motor input, motor integration, and general sensation.
The chemolithotrophs that metabolize reduced sulfur compounds using oxygen as a terminal electron acceptor in the Winogradsky column include ________.
A. Beggiatoa B. cyanobacteria C. Chromatium D. Desulfovibrio