Activated sludge is used in which sewage treatment step?

A. Secondary
B. Tertiary
C. Primary
D. All of these choices are correct.


Answer: A

Biology & Microbiology

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When performing gene therapy, DNA can be introduced into human cells by using genetically engineered ____, which

are designed to deliver their genetic material into the cells they infect.

a. sheep cells b. mouse cells c. bacteria d. plasmids e. viruses

Biology & Microbiology

Males tend to be affected in greater numbers by X-linked recessive genetic disorders than are females because

A. expression of the recessive gene is inactivated by the other X chromosome in females. B. males have only one X chromosome. C. males have a double dose of the gene. D. Y chromosomes are destabilized by the X chromosomes. E. females have only one X chromosome.

Biology & Microbiology

The existence of nest-building in crocodiles and birds led to a prediction that this behavior was also present in

A) ancestral lizards. B) mammals. C) dinosaurs. D) invertebrates.

Biology & Microbiology

Transfer of random pieces of DNA mediated by phage is known as

A) transformation of competent cells. B) generalized transduction. C) conjugation. D) transposition. E) specialized transduction.

Biology & Microbiology