Answer:
A dorsal root (sensory or afferent) and a ventral root (motor or efferent) originate from the medulla. They unite near the intervertebral foramen, forming the spinal nerve. The nerves emerge from the intervertebral foramen, dividing into ventral and dorsal ramus.
Explanation:
The nerve is a set of nerve fibers perceptible to the naked eye and wrapped in connective tissue. They are made up of roots, trunks and nerve branches (some of them come together and form plexuses).The spinal nerve originate from the spinal cord in the form of 31 pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. They emerge from the spinal cord through two roots: dorsal roots, made up of sensory fibers that come from the sensory neurons of the spinal ganglion and that penetrate the spinal cord through the posterolateral and ventral root, made up of motor fibers, coming from the motor neurons of the anterior horn and visceral of the lateral horn of the gray matter of the spinal cord. This root exits the spinal cord through the anterolateral groove, then joins the posterior root to form the spinal nerve, which exits the vertebral canal through the corresponding intervertebral foramen.Each spinal nerve, after leaving the vertebral canal, emits two primary ramus: the dorsal ramus, contains somatic and visceral fibers that go to the skin and muscles of the back and the ventral ramus, which supplies the ventrolateral surface of the skin, body wall and extremities.
Answer:
ur answer is A
Explanation:
just took the test good luck :)
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Answer:
D
Explanation:
Nutrition wise euglena is a producer, but locomotion wise it is classified as animal. Other example is chlamydomonas
Answer:
In an ancestral elm species, mutations gave rise to the phenotypic trait "winged-seeds". Subsequently, selection favored elm plants with winged-seeds that diverged over time to become a separate species
Explanation:
A mutation is a genetic change in the DNA sequence. In general, mutations have a negative impact on the fitness of the individual (i.e., mutations are generally deleterious) and therefore they disappear from the population. However, there are situations where mutations are beneficial and confer an adaptive advantage, thereby increasing their frequency in the population. In this case, mutations associated with the formation of winged-seeds conferred an adaptive advantage (i.e., higher seed dispersal capacity) to individuals who had this phenotypic trait, thereby these individuals had more chances to reproduce and pass their genes to the next generation. Eventually, Elm plants with winged-seeds accumulated sufficient genetic differences to prevent interbreeding, leading to the formation of a separate species.
