Answer:
Mold fossils A fossilized impression made in the substrate; a negative image of the organism.
Cast fossils Formed when a mold is filled in.
Trace fossils or Ichnofossils Fossilized nests, gastroliths, burrows, footprints, etc.
True form fossils Fossils of the actual animal or animal part.
The statement about the tundra that is true is that there are two main categories of the tundra biome.
When alzheimer disease sets in early and impacts those under age 60, the final phase of the disease or death typically occurs around 3 to 5 years after the first signs of the disease appear. Alzheimer's disease is the most common type of dementia, which is represents the memory loss and other cognitive abilities serious enough to interfere with normal life. Alzheimer accounts for about 60 to 80 percent of dementia cases.