You have isolated two mutations in the Lac operon that cause constitutive expression of Lac genes. You designate these mutants Lac1– and Lac2–. Making use of an F' that carries the Lac operon with the LacY gene mutated, you construct strains that you test for both ß-galactosidase activity and Lac permease activity with results shown below.

     

Classify each mutation as dominant or recessive and as cis- or trans-acting, giving the experimental result that allows you to arrive at each conclusion. Finally, deduce what type of Lac mutation best fits the properties of Lac 1– and of Lac 2–.

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#Question id: 5046

#SCPH06 I Botany

During early cleavage stages in drosophila, nuclei divide through 13 cycles in the absence of any cytoplasmic cleavage. This division creates an embryo of many nuclei contained within one shared cytoplasm surrounded by one common plasma membrane, this process is called as-

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#Question id: 12759

#SCPH06 I Botany

As climate changes because of global warming, species? ranges in the northern hemisphere may move northward. The trees that are most likely to avoid extinction in such an environment are those that

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#Question id: 3054

#SCPH05 I Biotechnology

A pure culture in exponential growth phase has a bacterial concentration of 6.4 x 10^8 cells/ml. If the bacterium has a generation time of 1 h, how long ago was the cell concentration 8.0 x 10^7 cells/ml?

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#Question id: 3008

#I Life Science/ Life Sciences Group – I-V

The structures present in the hay infusions used in experiments on spontaneous generation that made them difficult to sterilize are

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#Question id: 23246

#SCPH01 Biochemistry

Which element in the Sanger sequencing actually terminates the chain elongation?