Answer:
O horizon
it is most important for growth of crops
hope it helps
<span>The delineation of an aquatic ecosystem is the process of spatial identification, mapping and recording of the site; description documents the critical components and processes that underpin the ecosystem values of the site, and develops conceptual model(s) and identifies threats.
Delineating an aquatic ecosystem often starts with defining the main aquatic elements (core elements). The core elements will often be distinct landforms or features such as a waterhole, a swamp, a lake or a river. Ecotonal areas may be included as part of the core element or may be considered as a separate zone. For example, riparian vegetation is often considered to be an integral part of a river ecosystem, even if only inundated in big flood events.
The area around the core elements that has a critical influence on ecosystem function is referred to here as the Ecological Focal Zone. Beyond this, the landscape may be usefully differentiated as a Zone of Influence and a Catchment Zone.</span>
All viruses have is a protein coat and a core of genetic material, either RNA or DNA. Unlike bacteria, viruses can't survive without a host. They can only reproduce by attaching themselves to cells. Unlike bacteria, most viruses do cause disease, and they're quite specific about the cells they attack.
There are differences between Eukaryotic and Prokaryotic cells. This difference is considered to be the most important distinction between groups of organisms. A Prokaryotic cell does not contain a nucleus. It only contains one chromosome and is a single-celled organism. It was the only form of life on earth for millions of years. Examples of a Prokaryotic cell are the different types of bacteria present today.
A Eukaryotic cell contains a nucleus; more than one chromosome and is typically a multi-celled organism. <span>Both plant and animal cells are eukaryotic cells.</span>
<span>The answer is shared an evolutionary
history. Homologous structures evolved
from the same ancestor structure. An example of homologous features is the four
limbs of all tetrapods. In birds, the forelimbs evolved
into wings while in crocodiles they still used for walking, and in humans, they evolved into hands. </span>
