The heart’s electrical system is responsible for making and conducting signals that trigger the heart to beat. These signals cause the heart’s muscle to contract. With each contraction, blood is pumped throughout the body. This happens 24/7 without us having to monitor it all the time so that our heart does not stop.
Answer:
By researching, I would think that the answer is D. Ice crystals melt as they fall through a warm layer of air and then refreeze into small ice pellets as they pass through a colder layer of air.
Explanation:
<em>During precipitation formation, if temperatures are at or below freezing, 0°C (32°F), at cloud level, water in the air freezes into ice crystals, and the crystals stick together to make snow. The snow starts to fall, and if the air column is freezing cold all the way down from the clouds to the ground, the precipitation stays frozen. It simply falls as snow.</em>
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<em>Sometimes, however, a temperature inversion occurs. Normally, the temperature decreases with increasing altitude. A temperature inversion is when a layer of warm air intrudes between the ground and the clouds.</em>
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<em>Under these conditions, when the falling snow reaches the layer of warm air, it melts. Then it hits the layer of cold air just above Earth’s surface and refreezes. This all happens very fast, and the result is tiny ice pellets called sleet.</em>
Answer: Option E.
A,B and C are correct.
Explanation:
Kidney is a bean shaped organ normally found in vertebrates. It is located posterior to the abdominal peritoneum. Kidney is well protected by ribs 10-12 , abdominal muscles, back muscles .kidney is about 11cm in length in adults. Kidney receives blood from the arteries and exist blood through the veins. Each kidney is attached to a ureter which harbour and carries urine to the bladder .Each kidney is approximately the same size as adult clenched fist(10cm). The main function of the kidney is excretion of wastes and urine.
<h2>The answer is:</h2>
B) All organisms that cannot synthesize their food by means of photosynthesis or chemo synthesis are heterotrophic.
<h2>Explanation:</h2>
All those organisms that cannot manufacture their own food and instead obtains its food and energy by taking in organic substances in the process of photosynthesis usually in the animals and plants. All animals, protozoans, fungi, and most bacteria are heterotrophs.
