Gene flow is the movement of genes across barriers such as mountains, oceans, or deserts. these barriers are usually natural. however, in some cases, they are man-made. which man-made example could serve as a barrier to gene flow?

Nephrons, the functional unit of kidneys, are responsible for formation of urine. the sentences describe situations that are the result of problems in the urine formation process. for the nephron shown below, match each situation to the step in the urine formation process where the problem lies.

Which statement about relative potential energy of electrons is correct? a. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 2 s orbital of the second electron shell. b. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 3 p orbital of the third electron shell. c. an electron in the 3 p orbital of the third electron shell has more potential energy than an electron in the 2 p orbital of the second electron shell.

Which action is a reflex action. a. asking for coffe in a cold climate b. blinking when light is flashed in the eyes c. drinking water when thirsty. d. swallowing food e. taking an exam