Poaceae groups, using the C3 and C4 photosynthetic pathways for carbon fixation. The C4 grasses have a photosynthetic pathway, linked to specialized Kranz leaf anatomy, which allows for increased water use efficiency, rendering them better adapted to hot, arid environments and those lacking in carbon dioxide. The C3 grasses are referred to as "cool-season" grasses, while the C4 plants are considered "warm-season" grasses. The grass family is one of the most widely distributed and abundant groups of plants on Earth. Grasses are found on every continent, including Antarctica with the presence of Antarctic hair grass on the Antarctic Peninsula. Grasses are
Largest organisms March 2014 in a soil sample collected from a riverbank in Siberia. Prior to this discovery, the largest virus was the peculiar virus genus "Pandoravirus", which have a size of approximately 1 micrometer and whose genome contains 1,900,000 to 2,500,000 base pairs of DNA. Both these viruses infect amoebas specifically. Largest organisms The largest organisms now found on Earth can be determined according to various aspects of an organism's size, such as: mass, volume, area, length, height, or even genome size. Some organisms group together to form a superorganism (such as ants or bees), but such are not classed as