At intermediate concentrations of actin subunits, the plus end of the filament remains in the T conformation, while the minus end adopts the D conformation because:

#Question id: 4534

#Unit 3. Fundamental Processes

The yeast Saccharomyces cerevisiae divides by budding: instead of dividing to produce two identical daughter cells, the so-called mother cell buds to produce a daughter cell, The HO gene is expressed only in mother cells and only at a certain point in the cell cycle,

#Question id: 4535

#Unit 3. Fundamental Processes

The activators bind—and the enhanceosome forms—in a highly cooperative manner, ensuring that all three activators must be present. The following are three ways the regulators might be binding cooperatively:

I- Through direct protein–protein interactions between them

II- By changes in the DNA caused by binding of one protein helping binding of another;

III- By the fact that the activators all interact simultaneously with the coactivator.

#Question id: 4536

#Unit 3. Fundamental Processes

The human b-interferon gene is activated in cells upon viral infection through some activators, EXCEPT one

#Question id: 4537

#Unit 3. Fundamental Processes

The enhancer DNA is __, but once the activators are bound it is relatively  , HMGA1 the DNA and thus helps the final structure form.

#Question id: 4538

#Unit 3. Fundamental Processes

We first consider a generic case. Gene A is controlled by four signals (1, 2, 3, and 4), each working through a separate activator (activators 1, 2, 3, and 4). Gene B is controlled by three signals (3, 5, and 6), working through activators 3, 5, and 6. It shows-

#Question id: 4539

#Unit 3. Fundamental Processes

The yeast S. cerevisiae exists in three forms: two haploid cells of different mating types—a and alpha and the diploid formed when an a and an a cell mate and fuse. The a cell and the a cell each encodes cell-type-specific regulators: a cells make the regulatory protein a1, and alpha cells make the proteins alpha1 and alpha2. A fourth regulatory protein, called Mcm1, is also involved in regulating the mating-type-specific genes (and many other genes) and is present in both cell types which shows Combinatorial Control.

The arrangement of regulators at the promoters of a-specific genes and a-specific genes is