Which is the role of the effector in a feedback loopa) it detects a change due to a stimulusb) it causes a response to a stimulusc) it is the response to a stimulus

How does pregnancy begin? a) a placenta forms in the uterus b) a sperm reaches an egg in the fallopian tubec) the blastocyst differentiates into two cell types d) contractions begin in the uterine wallapex

How are the testes and ovaries similar? a. both produce sex cells. b. both connect internal reproductive organs to the exterior. c. both transport sex cells from their site of production. d. both store mature sex cells.

The distant ancestors of tigers may have had bodies without stripes. use the theory of natural selection to explain how tigers may have evolved to have stripes.