Which of the following events occurs initially when Escherichia coli cells are in a gradient of a chemorepellent?

A. Flagella rotate clockwise
B. CheY is phorphorylated
C. CheA autophosphorylates
D. Cells tumble


Answer: C

Biology & Microbiology

You might also like to view...

What information is provided by the fossil record that cannot be provided by examining living organisms?

A. All of the answer options are correct. B. a record of extinct species C. absolute dates for when different taxa diverged D. records of environmental conditions E. timing of mass extinctions

Biology & Microbiology

In an antibody- mediated immune response,

what causes effector helper T cells to release cyokines?

a. binding to antigen presenting dendritic cells b. binding to a bacterial complement c. binding to a naive helper T cell d. binding to a B cell e. engulfing a bacterium

Biology & Microbiology

RNA silencing involves

A) miRNAs. B) siRNAs. C) double-stranded RNA. D) a protein called Dicer. E) All of these

Biology & Microbiology

The ________ valves prevent blood from flowing back into the heart once it has left the ventricles

Fill in the blank(s) with correct word

Biology & Microbiology