Activator or repressor proteins which bind DNA to regulate the transcription of genes do so mainly by: A. Covalent interactions between the protein and specific bases in the major groove of DNA B. Covalent interactions of Zn2 atoms with the phosphodiester backbone C. Non-covalent interactions between the protein and specific bases in the major groove of DNA D. Covalent interactions with nearby nucleosomes E. Answers B and D are correct

C. Non-covalent interactions between the protein and specific bases in the major groove of DNA

Explanation:

Activator or repressor proteins are proteins with specific DNA-binding domains that have affinity by one or two DNA strands. In general, these proteins interact with the major groove of the B-DNA structure since this structure exposes more functional groups for binding. Non-covalent interactions are a type of interaction that does not involve the sharing of electrons. The interaction between proteins and DNA is due to the combination of different non-covalent interactions, which can be classified into four major types: van der Waals, hydrophobic, hydrogen and ionic interactions.

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.