The answer is C. Carbon is versatile and easily combines with other elements
Answer:
Electrical gradient.
Explanation:
Ions DO NOT move in Ion channels by simple diffusion because most ion channels can be:
I) selective of ions pass through it.
II) operating on a "open and close" principle. Where it opens or close on its own accord OR does so ONLY when induced by a specific influence like change in voltage of ion channels.
IN ADDITION to the concentration gradient, ELECTRICAL GRADIENTS (change in membrane voltage) affects the movement of ions through ion channels
Mosquitoes have a 6-tube system in their "snout". It's a big big needle with 6 parts to it. 4 of those parts are used to pierce the skin of the human. The other 2 parts are 2 tubes. One of those tubes sends saliva from the mosquito down into the human. The other sends blood up from the human into the mosquito.
Now, unlike some viruses (like dengue and Zikka), HIV cannot replicate inside a mosquito. HIV replicates inside human T-cells...there aren't any of those inside a mosquito gut. Eventually the HIV is destroyed and never makes it to the saliva of the mosquito - so the mosquito can never infect a human with HIV.
Answer:
you are using your shoulder muscle. The reason you are using this muscle is when you put your arm strait up there is no reason to use a bicep or tricep muscle.
Explanation: