Given the age of the meteorite is 4.5 billion years old with 78 atoms of lead-206 the answer should be B. 156. The half-life of uranium-238 in order to decay into lead-206 is 4.46 billion years, which means that the original number of atoms is 156.
Answer:
The first line of defense involves skin.
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.
Prostaglandin similarity with hormones is in the effect they achieve by binding to the receptors. Their effects are mediated by paracrine or autocrine mechanisms. Another hormone characteristic is the ability to stimulate adenylate cyclase activity, producing cAMP as the second messenger.
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On the other hand, prostaglandins differ from hormones in that they are not produced at a specific place but in many different places throughout the body. Also, the metabolic degradation of prostaglandins is very rapid.</span>
Lively is your answer.
Hope this helped! (:
