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–.

TLS Online TPP Program

#Question id: 5615

#SCPH01 Biochemistry

The fast block to polyspermy is achieved by:

TLS Online TPP Program

#Question id: 1284

#SCPH05 I Biotechnology

The collagen triple-helix domain is NOT:

TLS Online TPP Program

#Question id: 19599

#SCPH05 I Biotechnology

The enthalpy change in a reaction does not depend upon

TLS Online TPP Program

#Question id: 13097

#SCPH06 I Botany

You are a scientist who is using genomics to currently study a new bacterial species that no one has ever studied before. The following sequence is a piece of DNA within the coding region of a gene that you have recently sequenced.

 

If you take any bacterial gene sequence, before you begin doing any sequence analysis on it, there are six potential open reading frames. Why are there six?

TLS Online TPP Program

#Question id: 10390

#SCPH06 I Botany

Phytochromobilin autocatalytically attaches to the PHY apoprotein through