The false statement is: (a) Transcriptional regulators usually interact with the sugar–phosphate backbone on the outside of the double helix to determine which DNA sequence to bind.
Transcriptional regulator or factor is protein with the ability to control and regulate gene expression at the transcription level by binding to DNA. Transcriptional factors have domain-DNA-binding domain which contains structural motif that recognizes DNA and it is responsible for the attachment to specific DNA sequence. It usually binds to the DNA major groove (hydrogen bonding) because it is less degenerate than that of the DNA minor groove.
Transcriptional factors also contain trans-activating domain for the binding of other proteins and signal-sensing domain for the detection of external signals.
Answer:
The structure of their noses.
Explanation:
Catarrhines are distinguished from platyrrhines by several traits but the main distinctive feature between them, is the structure of their noses. This forms the basis of their names.
Platyrrhines are characterized by laterally-placed, rounded nostrils or flat-nosed while catarrhines have narrow, downward-facing nostrils or hooked-nosed.
Another distinguishing feature include their dental formulation which is 2.1.2.3 in catarrhines and 2.1.3.3 in platyrrhines.
The skull structure of catarrhines have frontal bone which make contact with the sphenoid bone unlike the platyrrhines.
Generally, catarrhines are much bigger in size than platyrrhines.
23. The answer would be the third option.
24. The answer would be the second option.
Explanation:
Complete answer:
A mature erythrocyte lacks nucleus and mitochondria so as to make a place for the accommodation of more hemoglobin and hence more oxygen molecules. Lack of such organelles also provides the peculiar biconcave appearance of RBCs that aids in efficient diffusion. Young mammalian RBCs are nucleated.
