Why Is an Accurate Estimate of Gestational Age Necessary Before

question 6

Multiple Choice

Why is an accurate estimate of gestational age necessary before maternal serum α-fetoprotein (MSAFP) is measured?

• A) It is only expressed early in pregnancy
• B) It is only expressed in the second trimester of pregnancy
• C) One must relate the MSAFP measurement to gestational age because the MSAFP levels change during the pregnancy
• D) If it is too late in the pregnancy to do more invasive testing, it's not worth doing MSAFP measurements
• E) Because it takes several days to do the MSAFP testing, it can be skipped and invasive testing if the pregnancy is beyond 16 weeks can be done

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Definitions:

Evolutionary History

A chronicle of the development and changes in populations or organisms over generations.

Three-Domain System

Classification system that places all organisms into one of three large domains—Bacteria, Archaea, and Eukarya.

Archaea

A domain of single-celled microorganisms without a nucleus, distinct from bacteria and eukaryotes, often found in extreme environments.

Eukarya

One of the three domains of life, consisting of organisms with cells characterized by a nucleus enclosed within membranes.