Why is it important to obtain a karyotype in a child in whom a clinical diagnosis of Down Syndrome is completely obvious?
While most cases of Down Syndrome are due to non-disjunction events, which are rare, some are due to chromosomal rearrangements such as a Robertsonian translocation, that is carried by one of the parents. It is essential to be able to tell the parents what the chances of having another child with this disorder.
Which kind of toxin would most directly interfere with glycolysis?
A molecule whose structure closely resembles that of glucose such that it is recognized by as a substrate for the enzyme, but is not metabolized.
What are the similarities and differences between prokaryotes and eukaryotes?
Both types of organisms are enclosed by a plasma membrane consisting of a phospholipid bilayer. Inside that membrane is the cytosol, where the components of the cell, including the DNA, are found. However, eukaryotes have internal features such as organelles, that are enclosed by their own membranes. The DNA in eukaryotes is found primarily in the nucleus, which is enclosed by the nuclear membrane. In prokaryotes, the DNA is found in a region of the cell, but not surrounded by a membrane. Furthermore, the way the DNA is organized and used (or expressed) differs between the two.