Process of how a human sperm is produced from a single 2N cell.

1.         Describe, with the aid of your own diagrams, the process of how a human sperm is produced from a single 2N cell.

                              Meiosis I                                          Meiosis I

             Meiosis II                                                                                          

Sperms are the male sex cells also referred to as gametes, and they are formed through a process called spermatogenesis. In a single day, millions of sperms are produced from the spermatogonia that are 2n cells located in the testes that consists of coiled structures known as seminiferous tubules. The process happens from puberty and goes on for the rest of the male’s life. In the testes, they are nourished by the Sertoli cells where they are protected from any form of assault. The spermatogonia cells mature into a primary spermatocyte.  That contains 23 pairs of homologues X and Y. The cell then goes through the process of meiosis I and produces two secondary spermatocytes. Meiosis II also happens and produces four haploid spermatids. The spermatids develop and produce mature sperms that are stored in the upper compartment of the tubules located in the testes.

2.         Describe in as much detail the path that a single blood cell will make while travelling from an artery in the stomach back to the same artery by the shortest route possible.

The stomach is supplied with blood from the abdominal aorta. The celiac artery branches from the aorta and supplies oxygenated blood to the stomach. Blood cells move through the hepatic veins in the artery to provide blood to the stomach and gather the deoxygenated blood from the stomach. The deoxygenated blood is transported through the hepatic veins to the liver through the portal venous system that empties into the inferior vena cava. In the liver, this blood is processed and detoxified before it is returned to the system.

3.         Explain how a molecule of starch you eat enters the blood stream

Starch is a form of complex carbohydrates that can be found in food such as bread. Once it is consumed, digestion starts in the mouth where the enzymes located in the mouth break down the molecules in starch. They are turned into smaller molecules. The conversion into small molecules makes it easy for the starch molecules to be absorbed into the absorptive cells that line the small intestine and into the bloodstream through individual cells. These cells are also referred to as enterocytes, and they absorb glucose with the help of a protein and sodium-based transporter molecule. The transporter molecule moves to the cell membrane and binds sodium in the gut. This action changes the shape of the transporter and makes it able to absorb a glucose molecule from the gut. The transporter then moves into the cell and releases the sodium and glucose. The glucose is then taken by a different transporter that takes it to the other side of the enterocytes and releases it into the bloodstream. The smaller molecules are referred to as the metabolic pool that is composed of simpler substances from the breakdown of nutrients. They include simple sugars, amino acids, fatty acids, and glycerol. The digestive system turns the starch into sugar that easily penetrates into the blood stream. Glucose in the body acts as a source of energy for the blood cells. Excess glucose may be consumed, and it is stored in the liver as well as the skeletal muscles. The glucose molecules in the liver are converted into a long-chained sugar referred to as glycogen. The stored glycogen breaks down during meals to provide energy to the body cells. Glycogen stored in the skeletal muscles also provides energy for individuals when exercising. A continuous supply of glucose in a human’s body is important because it provides energy.