An operon is controlled by a repressor. When the repressor binds to a small molecule, it is released from binding to DNA near the operon. The operon is never expressed if a mutation prevents the repressor from binding to the small molecule. The type of control illustrated is:
A. negative inducible.
B. attenuation.
C. negative repressible.
D. positive inducible.
E. positive repressible.
Ans: A. negative inducible.
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a. True b. False Indicate whether the statement is true or false
The division of the nervous system that integrates sensory information and coordinates the body's response is the nervous system.
A. peripheral B. central C. somatic D. autonomic E. sympathetic
The requirement of cold weather before a particular plant process occurs (e.g., germination) is known as ____
a. the biological clock b. vernalization c. photoperiodism d. biennial life cycle e. perennial life cycle
What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?
A) There is considerable genetic variation in garden peas. B) Traits are inherited in discrete units and are not the results of "blending." C) Recessive genes occur more frequently in the F1 generation than do dominant ones. D) Genes are composed of DNA.