When someone stands with their knees locked, they may feel dizzy, nauseous, and possibly faint due to a drop in blood pressure. this resulting drop in blood pressure would be classified as the
a
stimulus
b
sensor
c
control center
d
effector

Consider the model of the oxygen cycle on earth. the majority of earth's oxygen reservoirs are found in the a) atmosphere. b) biosphere. c) hydrosphere. d) lithosphere.

Which statement best describes the relationship between an allele and a gene? question 1 a. an allele is a variation of a gene that can be expressed as a phenotype. b. an allele is the part of a gene that attaches to messenger rna molecules. c. an allele is a segment of a dna molecule that controls replication of a gene.

Which of the following describes a difference when gram-positive bacteria are compared to gram-negative bacteria?