The _____ is a type of regulator protein that binds to a region of DNA in the promoter of a gene called the operator and prevents transcription from taking place.

A. inducer
B. repressor
C. activator
D. inactivator
E. terminator


Ans: B. repressor

Biology & Microbiology

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When protists feed on solid nutrients such as bacteria by phagocytosis, they are said to be using ________ nutrition.

A. holozoic B. endozoic C. saprozoic D. parasitic

Biology & Microbiology

Four of the five answers listed below are accepted as valid explanations of genetic behavior. Select the

exception. a. blending b. dominance c. segregation d. independent assortment e. probability

Biology & Microbiology

Compared with eukaryotic chromosomes, bacterial chromosomes are ________

A) large, mainly organized in single-gene transcription units without introns B) small, with high gene density C) small, mainly organized in single-gene transcription units with introns D) large, triple-helix, Z-DNA, organized in single gene units with introns E) large, mainly organized in polygenic transcription units without introns

Biology & Microbiology

What is the typical osmolarity of most body fluids in humans and other mammals?

a. about 225 mOsm/L b. about 300 mOsm/L c. about 1000 mOsm/L d. about 1500 mOsm/L

Biology & Microbiology