As a result of immunodeficiency, most infected cats do not show symptoms and have normal life expectancy, however they are prone to developing other infections and certain types of cancer. A retrovirus, such as FIV, inserts a copy of its genetic material into the DNA of a host cell, where it can replicate. FIV is a lentivirus. a specific type of retrovirus that can take months, or even years to incubate, so the virus is slow moving, capable of lying dormant in the body before causing symptoms.
A fossil is the remains or traces of a once-living plant or animal that was preserved in rock or other material before the beginning of recorded history.The term also is used to describe the fossil fuels (oil, coal, petroleum, and natural gas) that have been formed from the remains of ancient plants and animals.nother type of fossil is the darkened carbon imprint of a buried plant or, more rare, animal. When an organism dies and is buried, pressure underneath Earth's surface compresses the organism between rock faces.
Lacy bryozoan fossil found in the Redwall Limestone. Fossils are the preserved remains of ancient life, such as bones, teeth, wood, and shells. Trace fossils represent the presence or behavior of ancient life, without body parts being present. Footprints, worm burrows, and insect nests are examples of trace fossils. Sedimentary rock contains fossils because it was built up layer upon layer, often trapping and preserving animals, plants, footprints, and more within the layers of sediment.