You have performed the following mating experiment using Hfr and F- strains of Escherichia coli: Hfr (thr+ leu+ gal+ strs) à— F- (thr- leu- gal- strr). Which of the following selective media would you use to score recombinant colonies?
A) minimal medium
B) minimal medium + streptomycin
C) minimal medium + threonine
D) minimal medium + streptomycin + threonine
Answer: B
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A. true B. false
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A. just before the periderm B. in the bark C. in the center D. in the roots E. just under the bark
If a hybrid is unable to produce sperm because meiosis does not proceed correctly, gene flow between the species is restricted by
A) hybrid infertility. B) gametic isolation. C) temporal isolation. D) hybrid viability. E) ecological isolation.
What contributes to limiting the size of a single cell? Cell size is limited due to:
What will be an ideal response?