I think it’s the length of growing land
Grain farming is done for economic activity and this makes it commercial. It is highly specialized and mechanised. The yield per acre is low so the farms are big. The yield is high per man so little manpower is needed for production. Grain farming is subject to market conditions like climate.
Hello!
In order for an animal to be a vertebrate, it must have a backbone. As can clearly be seen in any image of a sponge, it is a highly asymmetrical simple animal and does not have a backbone. Therefore, a breadcrumb sponge is not a vertebrate, or is an invertebrate.
I hope this helped!
Louisiana. Hope this helps