A scientist focusing on the evolutionary history of specific significant traits is engaged in cladistics.
Cladistics is a method of biological classification in which organisms (plants and animals) are grouped based upon shared significant derived characteristics (synapomorphies). Cladistics identifies various significant shared traits that can be traced to the most recent common ancestor of a group of species and that are not found in more distant groups and ancestors. Cladistics uses various anatomical, molecular and genetic characteristics of organisms.
Gametogenesis produces human egg and sperm cells
In multi-celullar organisms , the cell cycle produces groups of cells that perform the same function. These groups of cells form what it is called a tissue. A tissue is made up of cells that all are specialised to perform the same function. A bunch of tissues form an organ. Organs are more complex in structure and functions.
lots of different organs together form an organ system.
The virus is unable to replicate.
