I'm not sure how exactly you wanted this question to be answered. You're either talking about the symmetry where animals would have two legs or two arms for example and thus producing a pair of each muscle on both sides of the body, or you're refering to the development of agonistic and antaonistic muscles where each of them served a different purpose; either extending or contracting.
According to endosymbiotic theory, the chloroplast evolved as a result of engulfment and assimilation of a Cyanobacteria by an eukaryotic cell.
Explanation:
- Endosymbiotic theory supports the view that ceratain organelles of the eukaryotic cell evolved as a result of engulfment of single celled organism.
- Evidences that support this theory is the presence of organellar DNA.
- It is assumed that Mitochondria evolved as a result of engulfment and assimilation of an aerobic prokaryote while Chloroplast evolved due to engulfment and assimilation of a photosythetic prokaryote by an Eukaryote.
- After the engulfment ,these organisms however escaped the phagocytosis and began to benefit the eukaryotic Host.
- Soon it lost many of its Genes to the eukaryotic nucleus and became dependent on the Host.
- Thus a symbiotic association was established between the prokaryote and the host.Giving rise to cell organelles.
Shaping. Each step in the learning process is called an approximation. An animal may be reinforced for each successive approximation toward the final goal of the desired trained behavior. Animals learn complex behaviors through shaping.
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Answer:
Extensive damage to oligodendrocytes in the cns could result in l<u>oss of sensation and motor control.</u>
Explanation:
Oligodendrocytes are presnt in glial cells of Central nervous System which comprises of Brain and spinal cord.They are related to the nerve cells. It provides support by production of glial cell line derived neutrophic factor (GDNF) and brain derived neurotrophic factor (BDNF) or insulin growth factor IGF-1 they reduce ion leakage and decrease the capacitance of the cell membrane. Due to intensive damage of the Oligodendrocytes the motor nerves and other nerves of CNS damages looses it activity.
These are mainly occurred due to peripheral injury or demylinated diseases like multiple sclerosis, leukodystrophies,cerebral plasy and other congential disorders.Some chemicals like fluorouracil causes damage to the oligodendrocytes.
