"Two bacterial strains were obtained: Hfr: his(+) leu(+) bio(-) ton(S) Str(S) and F(-): his(-) leu(-) bio(+) ton(R) Str(R) . After an uninterrupted conjugation, you want to select ALL the F(-) recombinants that are leu(+). Which of the following media would you use for this selection?a. Complete medium containing streptomycinb. Minimal medium containing streptomycinc. Minimal medium containing leucine and streptomycind. Minimal medium containing sodium azide and leucinee. Minimal medium containing alanine, leucine, and streptomycinf. Minimal medium containing biotin, histidine, and streptomycing. Minimal medium containing alanine. h. Minimal medium containing alanine, biotin, and sodium azide."

Suppose that on a small island off the coast of scotland, 32 percent of the population has blue eyes, which means that these individuals must be homozygous for the blue eye color gene (bb). the only other eye color found on the island is brown, and individuals that are homozygous for the brown eye color gene (bb) or heterozygous (bb) will have brown eyes because brown is the dominant gene. assume this population is in hardy-weinberg equilibrium. if 100 babies are born next year, how many of these would you expect to have brown eyes and be heterozygous? a. 58 b. 49 c. 29 d. 43

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).

Math focus 4. calculate a map has index contours at 250 m, 500 m, and 750 m. what is the contour interval?