A Case Study. The sputum from two patients was being tested for the presence of M. tuberculosis . Patient 1exhibited clinically obvious TB. Patient 2 did not exhibit clinically obvious TB, but had been in contact with patient 1. The process of testing the sputum samples from patients 1 and 2 included the use of a positive control (test sample/culture). M. tuberculosis was isolated from the sputum samples of both patients. DNA fingerprinting revealed that the isolates from patients 1 and 2 were not identical. Which of the following possibilities most likely occurred?
A) Both patients were infected from a common source
B) Laboratory error resulted in one patient specimen being contaminated with another patient specimen
C) Poor handling of the test culture allowed cross contamination to patient 2
C) Poor handling of the test culture allowed cross contamination to patient 2
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Which of the following is part of the endomembrane system of a eukaryotic cell?
A. nuclear envelope B. Golgi apparatus C. vesicles D. All of the answer options are correct.
Ecomorphs are
a. not very closely related members of the same genus that appear very different from each other and that live in very different habitats. b. closely related members of the same genus that appear very similar to each other although they live in very different habitats. c. members of the same species that appear very similar to each other although they live in very different habitats. d. not very closely related members of the same genus that nevertheless appear very similar to each other and that live in very similar habitats. e. closely related members of the same genus that appear very similar to each other and that live in very similar habitats.
In the section "Investigating Life: Size Matters in Fishing Frenzy", a population declines when
A. death rate exceeds reproductive rate. B. reproductive rate exceeds death rate. C. reproductive and death rates are equal. D. smaller animals are selectively removed. E. animals are removed randomly.
Gymnosperms are seed plants that produce seeds ____
a. inside ovules b. on the surface of ovules c. inside fruits d. on their waxy needles e. from a microspore