多选题
Whereas much is known about causes and consequences at the molecular
level, and in spite of an enormous accumulation of chemical and morphological
data on embryos of various kinds, {{U}}
our understanding of how genes
control morphogenesis is still far from complete.{{/U}} Perhaps one
reason for this is that molecular biologists and morphologists speak different
languages. Whereas the former speak about messenger-RNA and conformational
changes of protein molecules, the latter speak of ectoderms, hypoblasts, and
neural crests. {{U}}
One solution to this predicament{{/U}} is to
try to find some phenomena relevant to morphogenesis which both the molecular
biologist and the morphologist can understand and discuss. As morphogenesis must
be basically the result of changes in behavior of the individual cells, it seems
logical to ask morphologists to describe the morphogenetic events observed in
terms of changes in cellular contact, changes in the rate of proliferation of
cells, or similar phenomena. Once this is done, it may be appropriate to ask
questions about the molecular background for these changes. One may, for
instance, ask whether variations in cell contact reflect alterations in the
populations of molecules at the cell surface, or one may inquire about the
molecular basis for the increased cell mobility involved in cell
dispersion.
The author's primary purpose is to:
- A. outline a procedure and discuss possible applications.
- B. evaluate an experiment in terms of its applicability to medical
research.
- C. propose a method for curing specific genetic disorders.
- D. explain a problem and suggest a solution for it.
- E. reveal the shortcomings of several attitudes toward genetic
research.