What is the dark organic rich material formed as a top layer in soil from the decayed remains of plants and animals

Dark rich organic material formed as a top layer in soil from the decayed remains of plants and animals is called humus.  

Explanation:

When dead parts of plants and animals are deposited in soil the decomposing bacteria present in the soil act on these remains and break them down.  

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.  

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.  

there are mainly three domains in biological classification namely; archaea, bacteria, and eukarya.

archaea includes all the prokaryotic cells which are characterized by their lipid membranes. they have branched hydrocarbon which is attached to glycerol through an ether linkage.

bacteria includes all the prokaryotic cells, the cell membrane of which are made up of the unbranched fatty acid chain. in addition, they are attached to glycerol through an ester bond.

eukarya includes all the eukaryotic cells, that is, the cells contain a nucleus and other membrane-bound cell organelles.

they can be autotrophic as well as heterotrophic, unicellular as well as multicellular

they include kingdoms like protista, plantae, animalia, fungi et cetera.

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explanation:

spiders belong to a group of arachnids.

arachnids have the following traits :

they have two body parts.

they have eight legs unlike insects which have 6 legs.

they have no wings.

these traits distinguish them from insects.

the information that antonio is doubting us the statement that spiders differences are as a result of being first to evolve.

this is because the evolution of one species is independent of the other species.