The tetanus is a disease caused by the bacterium Clostridium tetani. The Clostridium tetani is a normal inhabitant of the soil and can easily contaminate dirty wounds, especially those due to farm practices. In the body, these bacteria produce a toxin called tetanospasmin. The toxin enters the central nervous system which is the brain and spinal cord where it blocks the mechanisms that inhibit motor neurons from firing when a muscle is relaxed. With this inhibition removed, the neurons fire repeatedly and continually stimulates the muscle, causing painful and increasingly stronger muscle spasms. The masseter or jaw muscles are often the first muscles involved, and it is the spasm of these muscles that gives rise to tetanus' common name lockjaw, also called trismus. The muscles of the face, neck, back, and proximal limbs are also commonly affected. The contraction of the facial musculature leads to a characteristic facial expression with a teeth-baring grin and raised eyebrows. Contraction of the back muscles may cause the back to arch posteriorly.
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Fossils are important evidence for evolution because they show that life on earth was once different from life found on earth today. Paleontologists can determine the age of fossils using methods like radiometric dating and categorize them to determine the evolutionary relationships between organisms.
Explanation:
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Cartilaginous fish conducts internal fertilization. Internal fertilization happens when the egg cell and sperm cells of the parents were fertilized inside the body of the parent. And the baby is developed over time.
The simplest answer is that water is polar, while lipids are nonpolar.
