Question

Precipitation test gives evidence from -
(a) Comparative embryology
(b) Comparative anatomy
(c) Comparative serology
(d) None of the above

Answer 1

hint: Precipitation test involves testing liquids or fluids in the body for the presence of molecules that are produced when foreign particles enter the body. The other tests observe and compare the structure of various species.

Complete answer:
- A precipitation test is a comparative serological test which shows whether the antigens are similar by measuring for the presence of antibodies in the body fluids.
- Precipitation reactions are based on the interaction of antibodies and antigens. They are based on the two soluble antibodies and antigens that come together to make one insoluble product, the precipitate. The antibody is known as the precipitin.
- Precipitation test is a part of comparative serology based on the discovery that injection of a species’ blood into an animal of another species leads to antibody production and rejection of the blood. The more phylogenetically closer the organism is to the human, the more precipitate is formed.

Additional Information:
- Serology is the study of blood serum and other body fluids for the identification of antibodies. Serologic testing helps in not only detecting pathogenic disorders but also autoimmune disorders.
- Comparative embryology is the branch of embryology that compares embryos of different species and finds the relation between them.
- Comparative anatomy finds the similarities and differences in the anatomy of organisms in relation to evolutionary biology.
So, the correct answer is ‘(c) Comparative serology’.

Note:
- Flocculation tests are a modification of precipitation tests.
- The different types of serological tests are agglutination, precipitation, fluorescent-antibody test, ELISA, radioimmunoassay, electrophoresis, and immunoelectrophoresis.