the answer is radiation
Radiation is the emission and propagation of energy. A substance does not need to be radioactive in order to emit radiation because radiation encompasses all forms of energy, not just those produced by radioactive decay. However, all radioactive materials do emit radiation.
The oldest fossils present at the bottom of rock layer whereas the youngest fossils are present in the top layer.
<h2>Rock layers from oldest to youngest</h2>
The rock layers that is located farthest from the ground surface are considered as the oldest rock layers and rock layers that are closest to the ground surface are considered as the youngest. A fossil is the remains or traces of plants and animals that lived long ago.
<h3>Presence of fossil</h3>
Those fossils which are present at the bottom of the rock layers are considered as the oldest fossil followed by the upper layer's fossil and so on. The fossils present at the top layer are the youngest fossils so we can conclude that oldest fossils present at the bottom of rock layer whereas the youngest fossils are present in the top layer.
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The smallest unit is species
I found that animals can be divided into five groups which are mammals, fish, birds, reptiles and amphibians
Answer:A vascular bundle is a part of the transport system in vascular plants. The transport itself happens in vascular tissue, which exists in two forms: xylem and phloem. Both these tissues are present in a vascular bundle, which in addition will include supporting and protective tissues.
Explanation: