The following CSS properties will be explained: 1  color. 2  background-color. 3  background-image.  background- 1 repeat. background-attachment.  background- 1 position. background.
The transmission of a signal through the nervous system can also be considered an example of long-distance signaling. Local signaling in plants is not well understood. Because of their cell walls, plants must have different mechanisms from animals. Plants and animals use hormones for long-distance signaling. In animals, specialized endocrine cells release hormones into the circulatory system, by which they travel to target cells in other parts of the body. Plant hormones, called growth regulators, may travel in vessels but more often travel from cell to cell or move through air by diffusion.
Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because: A) Only target cells retain the appropriate DNA segments. B) Intracellular receptors are present only in target cells. C) Most cells lack the Y chromosome required.) They no longer have active nuclei. B) They no longer carry receptors for signal molecules. C) They have been shunted into G0. D) They can no longer bind CDK to cyclin.