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Lelechka [254]
3 years ago
9

A crystal is always... A. a hexagon B. a cube C. a liquid D. none of these

Biology
2 answers:
NARA [144]3 years ago
3 0
D because its a solid
boyakko [2]3 years ago
3 0
The answer is none of these or none of the above
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I would have to say skin or hair
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The structure that prevents backflow of blood into the left atrium is the . The vessel that carries oxygen-rich blood to tissues
iVinArrow [24]

Answer:

The structure that prevents backflow of blood into the left atrium is the mitral valve.

The vessel that carries oxygen-rich blood to tissues is the aorta.

The capillaries receiving blood flow from the left side of the heart are the Systemic capillaries.

The structure that is located anatomically between the aorta and the left ventricle is the Aortic semilunar valve.

Explanation:

The left atrium receives oxygen-rich blood from the pulmonary vein and passes it to the left ventricle. The back-flow of blood from the left ventricle into the left atrium is prevented by mitral which is a bicuspid valve. The vessel that carries oxygen-rich blood to tissues is the aorta.

Aorta receives oxygen-rich blood from the left ventricle and pumps it into its branches to deliver the blood to the body tissues. Systemic capillaries are the blood vessels that obtain the oxygen-rich blood from the left ventricle through the aorta. Systemic capillaries serve as the site for the exchange of gases and nutrients.

The aortic semilunar valve is located Aortic semilunar valve is the half-moon shape valve present between the left ventricle and aorta to prevent the black flow of blood to the left ventricle.

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3 years ago
Why is it essential that the regulatory mechanisms that activate glycogen synthesis also deactivate glycogen phosphorylase?
Marta_Voda [28]

Answer:

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vova2212 [387]
I think the correct answer from the choices listed above would be the second option. In multicell organisms, cells that work together to perform a certain function form <span>Organs. Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>
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List two "firsts" in the animal kingdom that a sponge can claim
Agata [3.3K]

Answer:

Two first the sponge can claim are

1. reproduce sexually

2. combine sperm and egg

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