A study of biology includes the study of the chemical basis of living organisms, DNA. Other related sciences include microbiology and organic chemistry. The word science comes from a Latin word scientica, which means knowledge, or information.
It supplies the stomach, iv Pulmonary Nerve: It innervates the lungs. Vagus is mixed in nature because it carries both motor and sensory fibres. These nerves arise from the spinal cord and are normally nine pairs, sometimes 10th unpaired nerve is also seen.
Rarely 10 pairs of spinal nerves are found. As soon as two roots come out of the vertebral column, they unite to form a very small branch, which immediately divides into three branches. It is a short branch supplying the skin and muscles of the dorsal side of the trunk. It is thicker, larger and supplies the skin and muscles of the ventral and lateral side of the trunk mostly, but in some cases it is also connected with the limbs.
It is a short fine branch, which arises near the origin of each ventral branch and joins sympathetic cord of its side. Distribution, Functions and Nature of Spinal Nerves: Except the first pair of spinal nerve, all are distributed to the skin and muscles of the respective parts of the body.
They carry impulses from the skin receptors to the spinal cord and from the spinal cord to the muscles. Thus, their nature is mixed. The first spinal nerve is also known as hypoglossal Nerve.
It supplies muscles of the tongue, floor of the buccal cavity and some muscles of the shoulder and back. It also takes part in the formation of brachial plexus.
It is a motor branch. The hypoglossal nerve, the second and the third spinal nerves form the brachial plexus. From the brachial plexus, the second nerve continues as a brachial nerve to the skin and muscles of fore-limb.
The 4th, 5th and 6th spinal nerves supply the skin and muscles of the body wall of the belly region. The 7th, 8th and 9th spinal nerves form the sciatic plexus, which gives off branches to the skin and muscles of the abdomen and hind-limbs.
This plexus also supplies some branches to the large intestine, genital ducts and urinary bladder. The tenth nerve is also known as coccygeal nerve, which is not commonly found in Rana.
Whenever this nerve is present, it emerges from the urostyle through an aperture and joins the sciatic plexus. The fine branches of 10th nerve supply the urinary bladder and cloaca.
There is a noteworthy point that the roots of seventh to tenth nerves first run inside the neural canal of the vertebral column for some distance to form a horse-tail shaped structure, the cauda equina.
Later on these nerves come out of the neural canal. It is a system of nerve fibres and ganglia which control and coordinate the involuntary activities of the visceral organs, such as secretion of digestive fluid, action of heart, etc. This system is autonomic in the sense that it regulates such activities of the body in which the will power of the animal is not involved, for example, the secretion of the digestive fluid is always under the control of autonomic nervous system, but the animal is not aware of it.
The autonomic nervous system is divisible into:Mitosis only produces two daughter cells while meiosis produces four out of the division. Each cell produced in mitosis is called a diploid cell since the exact number of chromosomes as the parents are retained in each of the two cells. The evolution of sexual reproduction describes how sexually reproducing animals, plants, fungi and protists could have evolved from a common ancestor that was a single celled eukaryotic species.
There are a few species which have secondarily lost the ability to reproduce sexually, such as Bdelloidea, and some plants and animals that routinely reproduce asexually (by apomixis and.
Mitosis Essay Examples. 14 total results. An Analysis of the Stages of Metabolism and Mitosis in the Life Process of a Cell. words. 1 page. A Study of Mitosis. words.
A Research on Cell Division in Meiosis and Mitosis. 1, words. 3 pages. A Experiment to Investigate Cell Reproduction Through Mitosis. 1, words. Essay # 1. Habitat and Habits Frogs: Rana tigrina is the most widely distributed species in Northern India. Generally frogs are found in ponds, tanks, pools, ditches, etc.
Biology: Biology, study of living things and their vital processes that deals with all the physicochemical aspects of life.
Modern principles of other fields, such as chemistry, medicine, and physics, for example, are integrated with those of biology in areas such as biochemistry, biomedicine, and biophysics.
Transforming media into collaborative spaces with video, voice, and text commenting.