4th quarter exam (Gen Bio II) Flashcards
word “petrified” means
Turning into stone
Five main types of fossils
petrified fossils, molds and casts, carbon films, trace fossils, preserved remains
form when minerals replace all or part of an organism.
petrified fossils
Water is full of dissolved minerals. It seeps through the layers of sediment to reach the dead organism. When the water evaporates, only the hardened minerals are left behind.
True
forms when hard parts of an organism are buried in sediment, such as sand, silt, or clay.
mold
forms as the result of a mold.
cast
All living things contain an element called
carbon
When an organism dies and is buried in sediment, the materials that makeup the organism breakdown. Eventually, only carbon remains
true
show the activities oforganisms.
trace fossils
Over time the footprint is buried in layers of sediment. Then, the sediment becomes solid rock.
true
Some organisms get preserved in or close to their original states.
Preserved remains
An organism, such as an insect, is trapped in a tree’s sticky resin and dies. More resin covers it, sealing the insect inside .It hardens into
Amber
An organism, such as a mammoth, is trapped in a pit and dies. The sinks into its bones and stops the bones from decaying.
Tar
An organism, such as woolly mammoth, dies in a very cold region. its body is frozen in, which preserves the organism-even
its hair
Ice
An animal is buried by, such as volcanic ash or silt, shortly after it dies. Its bones are protected from rotting by the layer of
Sediment
More sediment accumulate above the animal’s remains, and minerals, such as silica (a compound of silicon and oxygen), slowly replace the calcium phosphate in the bones
Layers
of tectonic plates, or giant rock slabs that make up Earth’s surface, lifts up the sediments and pushes the fossil closer to the fossil
Movement
from rain, rivers and wind wears away the remaining rock layers. Eventually, or people digging for fossils will expose the preserved remains.
Erosion
(fossils can form in several ways)
occurs when minerals carried by water are deposited around a hard structure.
Permineralization
(fossils can form in several ways)
forms when flowing water removes all of the original tissue, leaving an impression.
natural cast
(fossils can form in several ways) record the activity of an organism.
trace fossils
(fossils can form in several ways) fossils are organisms t h a t become trapped in tree resin that hardens after the tree is buried.
Amber-preserved
(fossils can form in several ways) form when an entire organism becomes encased in material such as ice.
Preserved remains
(fossils can form in several ways)
• Specific conditions are needed for fossilization.
• Only a tiny percentage of living things became fossils.
true
are evidences of organisms that lived in the past. They can be actual remains like bones, teeth, shells, leaves, seeds, spores or traces of past activities such as animal burrows, nest and dinosaur footprint or even the ripples created on a prehistoric shore.
Fossil
