<em>Dark rich organic material formed as a top layer in soil from the decayed remains of plants and animals is called humus. </em>
<u>Explanation:</u>
When dead parts of plants and animals are deposited in soil the <em>decomposing bacteria present in the soil act on these remains and break them down. </em>
Plant and animal bodies contain organic compounds which are broken down into inorganic nutrients by the decomposers. These nutrients are taken up by producers and the nutrients restart their journey in the food chain.
<em>Humus is identified by its rich dark color. The amount of humus decides how fertile the soil is. More the humus content fertile is the soil. </em>
<span>Why is carbon so abundant in living things when oxygen is the most abundant element on Earth?
</span>a. Carbon atoms can bond with one another to make chains and cyclic structures whereas oxygen atoms cannot form chains or cyclic structures.<span>
Embolic strokes that are also known as ischemic stroke are cause by the blockage of an artery to the brain which is usually a blood clot that has been formed may it be in the heart. This then can cause a stroke.
