Light travels in lines.
Fill in the blank

Light travels in straight lines.

Explanation:

Once light has been produced, it will keep travelling in a straight line until it hits something else.

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.