Variation, in biology, any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation).
The endosymbiotic theory stated
that the mitochondria of eukaryotic cells are actually prokaryotic bacteria
which were once engulfed by prehistoric eukaryotic cells as a result of
evolution.
Therefore to answer this
question, here are some characteristics:
1 Both mitochondria and prokaryotic cells contain their own
DNA.
2 Neither of the two have
true nuclei, but they do have a space in which their DNA is enclosed.
3 Mitochondria and prokaryotic cells have similar
transcriptional machinery, which means that they have the same process of
making RNA from DNA.
<span>4 Mitochondria
contain their own genome, and the formation of their genome in most organisms
is circular similar to prokaryotes.</span>
Correct answer is label B. on the purple shaded area which is inside the ventral horn and dorsal.
Spinal cord is termed as tubular or long thin structure which is made of nervous tissue. It is being extended to the lumbar region which is found in the brainstem from the medulla oblongata.
This is enclosed in the central canal which contains cerebrospinal fluid of the spinal cord. If we combine spinal cord and the brain we come up with Central Nervous System.
Between the second and first lumbar vertebrae is where spinal cord extends and it is where it ends.
<em>The major function of spinal cord is nerve signal transmission from motor cortex to body. </em>
Answer:
A. Plant cells have cell walls and chloroplasts, Animal cells do not.
Explanation: