The way that I know it is that cells make up tissue, tissue makes up organs, and organs make up organ systems.
Answer:

Explanation:
The distance to the Sun is 5,890,000,000,000. We need to write this distance in km.
A number can be written as
in scientific notation where x is a real no and y is any integer.
There are 10 zeros in the given number and also there are 12 digits after. It would mean that,

So, the distance in scientific notation is : 
The process by which metabolic waste is eliminated from an organism.
The right answer is Lichen.
In ecology, a pioneer species is one of the first forms of life that colonize or recolonize a given ecological area.
Lichens are composite organisms resulting from a symbiosis between at least one heterotrophic fungus called mycobionte, representing 90% of all, and microscopic cells with chlorophyll (green algae or cyanobacteria autotrophic for carbon) called "photobionts" .