The depicted region contains two genes (cI and cro) and three promoters (PR, PL, and PRM), these promoters are direct the transcription such as;

a) PR and PL are is a weak promoter and only directs efficient transcription when an activator is bound just upstream

b) PR and PL are strong, constitutive promoters, they bind RNA polymerase efficiently and direct transcription without     help from an activator

c) PRM, is a weak promoter and only directs efficient transcription when an activator is bound just upstream

d) PRM are strong, constitutive promoters, they bind RNA polymerase efficiently and direct transcription without help from an activator

Which of the following from the above combination is correct ?

#Question id: 9620

#Unit 9. Diversity of Life Forms

The two extant species that are most closely related to each other are

#Question id: 9619

#Unit 9. Diversity of Life Forms

A common ancestor for both species C and E could be at position number 

#Question id: 9617

#Unit 9. Diversity of Life Forms

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed 3-chambered hearts (2 atria, 1 ventricle). Birds and mammals, however, are alike in having 4-chambered hearts (2 atria, 2 ventricles). The 4-chambered hearts of birds and mammals are best described as

#Question id: 9615

#Unit 9. Diversity of Life Forms

In angiosperm plants, flower morphology can be very intricate. If a tree, such as a New Mexico locust, has flowers that share many morphological intricacies with flowers of the sweet pea vine, then the most likely explanation for these floral similarities is the same general explanation for the similarities between the

#Question id: 9614

#Unit 9. Diversity of Life Forms

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to

#Question id: 9611

#Unit 9. Diversity of Life Forms

If, someday, an archaean cell is discovered whose SSU-rRNA sequence is more similar to that of humans than the sequence of mouse SSU-rRNA is to that of humans, the best explanation for this apparent discrepancy would be