Multiple Choice
Scientists have found that the lifetimes of mRNAs coding for pair-rule regulatory elements in Drosophila embryos may be measured in minutes.What does this suggest about the overall developmental plan of an animal body?
A) mRNAs in general have short lifetimes;this is not a surprising finding.
B) Each segment specified by pair-rule mRNAs is completely determined in the embryo in a very short time.
C) Building an animal body requires a sequence of steps;each of these steps is precisely timed.
D) Timing of pair-rule sequence determination is not as important as spatial signaling.
Correct Answer:
Verified
Correct Answer:
Verified
Q2: Suppose there was a mutation in the
Q12: All of the following characteristics are shared
Q13: Programmed cell death,apoptosis,plays a major role in
Q15: Communication within and between cells of an
Q17: All of the following are true of
Q19: In combination,what do the products of gap
Q20: Evolutionary theory has until recently stressed genetic
Q21: When is a cell considered differentiated?<br>A)when a
Q37: When the Bicoid protein is expressed in
Q45: The predominant mechanism driving cellular differentiation is