200 different types of cells are in the human body
~Hello
Fossils are one of the best evidence of evolution, mainly because they are the remains of living organisms from the past, which allow us to compare them with living organisms. However, the fossil record is notoriously incomplete and it is also biased in favor of animals with hard body parts, such as skeletons and shells. Soft bodied organisms and soft body parts are rarely preserved and there are often huge gaps in some evolutionary sequences. For example, Archaeopteryx is the earliest known bird, but it is already a bird, nothwithstanding some of the features that are unquestionably reptilian. The earliest known reptile with feathers is Longisquama, but there is a gap of some 75 million years between Longisquama and Archaeopteryx, and nothing has yet been found that are intermediate between these two important fossils.
Finally, DNA is virtually unobtainable from fossils, making it nearly impossible to compare the DNA of most fossils with living organisms. In terms of phylogenetic tree construction, DNA data is far superior to fossil evidence. However, if not for the existence of fossils, DNA data alone would be unconvincing as evidence of evolutionary change.
~ Hope this could help
Answer:
Pass information by generating electric signals
Explanation:
Neurons are the fundamental unit of the nervous system. Neurons send information across the body through generation of electric signals called as action potential. There are basically three types of neurons
a) Sensory neurons which carry information from the sense organs in the form of impulse to the central nervous system (CNS)
b) Motor neurons – These carry information from the CNS to the body parts such as sense organs, muscles etc.
c) Interneurons – They are connecting neurons which are responsible for transferring information from one neuron to the other neuron.
Answer:
Left atrium
Explanation:
The four pulmonary veins return oxygenated blood to the left atrium.
Hi there!
Great question!
There are different organisms on Earth and they all get energy differently.
For example, a plant gets its energy from the sun. The sun shines down on it, giving the plant energy to grow.
On the other hand, a wolf would get its energy from the food it eats. When the wolfs belly is full, it has more energy to run around and catch more of it!
Hope this helps! :D
