Ecosystem is that it is a community or group of living organisms that live in and interact with each other in a specific environment.
For instance, tropical forests are ecosystems made up of living beings such as trees, plants, animals, insects and micro-organisms that are in constant interaction between themselves and that are affected by other physical (sun, temperature) or chemical (oxygen or nutrients) components.
An ecosystem consists of a community of organisms together with their physical environment.
Ecosystems can be of different sizes and can be marine, aquatic, or terrestrial. Broad categories of terrestrial ecosystems are called biomes.
In ecosystems, both matter and energy are conserved. Energy flows through the system—usually from light to heat—while matter is recycled.
Ecosystems with higher biodiversity tend to be more stable with greater resistance and resilience in the face of disturbances, or disruptive events.
Below are the choices, the answer is no. 3:
1) The virus was descended from a common ancestor of bird, pig, and human flu viruses.
2) The infected individuals happened to be infected with all three virus types.
3)Related viruses can undergo genetic recombination if the RNA genomes mix andmatch during viral assembly.
4)The human was likely infected with various bacterial strains that contained all three<span>RNA viruses.</span>
Each cell is alive even if it is part of a multi celled body, and all living organisms consist of one or more cells. Also, cells reproduce by dividing so it follows that all existing cells must have arisen by division of other cells. As a cell divides it passes it hereditary material- its DNA- to offspring.
The right answer is C) vector
In molecular biology and genetic engineering, vectors are DNA molecules that allow the propagation of sequences of interest. These are chimeric DNA molecules such as plasmids or artificial bacterial chromosomes, containing an origin of replication and one or more genetic markers. The origin of replication allows the maintenance of the vector in the target cell during generations.