Germ-free animals are often more susceptible to infections and serious disease than are animals with a typical complement of normal microbiota. Based on this observation, which of the following would be an appropriate conclusion?
A. Normal microbiota are incapable of causing disease
B. Normal microbiota stimulate the development of the immune system
C. Normal microbiota are parasitic
D. Normal microbiota are opportunists
E. Normal microbiota provide supplemental nutrition to the host
Ans: B. Normal microbiota stimulate the development of the immune system
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A. BRCA1. B. Rb. C. NF1. D. p16. E. Rb and p16.
Bacteriophages were used by Hershey and Chase to further elucidate our understanding of heredity. Why were bacteriophages used?
What will be an ideal response?
The burning of fossil fuels by cars and factories has most affected the ______________ cycle.
Fill in the blank(s) with the appropriate word(s).
One parent carries a dominant allele (AL) that is lethal in early life in homozygotes. The other parent is homozygous for the wild type allele (A+) of the same gene. What is the expected dominant:wild type phenotype ratio for their offspring?
A) 100:0 B) 75:25 C) 50:50 D) 25:75 E) 0:100