The answer to this question would be: B<span>. It relaxes blood vessels in Harvey’s penis, allowing them to expand.
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Viagra active component is sildenafil citrate which has the ability to relax the smooth muscle in the artery and dilate the arteries of the penis. As the arteries in penis dilate, the blood flow into penis will be increased. This will make penis filled with blood and give pressure to nearby veins causing them to close. All this event cause increased pressure in penis that was making the erection
ATP stand for adenosine triphosphate. It consists of the nitrogenous base adenine and is linked to a sugar molecule. It is necessary for human life because it gives the body energy
Answer:
those best suited to demands of environment survive
The answer is d. chromosomes help an organism produce usable energy
Answer:
a) i) Xylem
ii) Upper epidermis
iii) Stoma
iv) Chroloplast
v) Palisade cell layer
b) By a waxy layer on the cuticle of the leaf
Explanation:
The plant's leaves have a large surface area that is capable of absorbing sunlight. The plant's waxy layer in the surface of the leaf protects it from the loss of water, as well as of diseases caused by the entry of microorganisms. The palisade cell's surface is a single layer of cells underneath the upper epidermis that is adapted to absorb light energy.
The waxy layer is a primary physical barrier composed of insoluble polymers and lipids whose function is to protect the leaves against the entry of harmful organisms including virus, bacteria and fungus. Moreover, the plant's waxy cuticle is also a barrier that prevents the loss of water and solutes.
