All of the following animals have placentas EXCEPT

a. kangaroos.
b. opposums.
c. echidnas.
d. koalas.
e. wombats.


C

Biology & Microbiology

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Blood agar is both a differential and enriched medium.

Answer the following statement true (T) or false (F)

Biology & Microbiology

Prions are of significance because they cause infections of

A. plants. B. prokaryotes. C. domestic animals and humans. D. fungi.

Biology & Microbiology

The Crenarchaeota, Thaumarchaeota, and Euryarchaeota are ________.

A. now classified with the bacteria based on genomic sequence analysis B. very closely related based on 16S rRNA comparisons C. photosynthetic Archaea D. the three phyla of the Archaea

Biology & Microbiology

A 1-year-old boy is evaluated for a suspected immune deficiency. He has a history since birth of eczema, recurrent rashes, and diarrhea. His white blood cell count (WBC) count is 6.75/uL (normal values: 5.0-10.8 x 103 uL) with a normal differential. Platelet count is 35,000 (normal values: 150,000- 350,000/uL), and the platelets are small. His IgG is 750 mg/dL (normal values: 600-1,500 mg/dL). IgM is 30 mg/dL (normal values; 75-150 mg/dL). IgA is 475 mg/dL (normal values: 50-125 mg/dL). IgE is 750 mg/dL (10-50 mg/dL). The boy's blood is typed as O-positive, and he does not have anti-A or anti-B antibodies. Flow cytometry performed on his blood shows 11% CD19 (normal values: 5%-20%) and 50% CD3 cells (normal values: 60%-80%) with a normal ratio of CD4:CD8. T-cell function tests are

abnormal. This boy most likely has: A. Bruton's tyrosine kinase deficiency. B. Wiskott-Aldrich syndrome. C. DiGeorge anomaly. D. ataxia telangiectasia.

Biology & Microbiology