Sara Szogas
Dr. E – Wednesday evening
Final Exam
10. The digestive system is essential to all living beings with complete or incomplete digestion systems. Incomplete digestion systems are considered primitive due to their long status on earth. They have evolved to a point, but the only entrance and exit still work together as one common function; eating and disposing of waste. Complete digestive system are much more complex as they have a digestive tract the food much travel through after it is ingested via the mouth. The tract ends with waste being eliminated from the anus, but what does the digestive system consist of? The mouth is the first stop as the teeth chew the food making it easier to swallow. The salivary glands play a part in digestion here as this accessory organ keeps the mouth stocked with saliva, moistening the digestive tract as a whole. Next, the food quickly enters the Pharynx, which is used a gate. The gate separated whether there is food or oxygen entering the body, then organizing it into its’ appropriate tube. The chewed food is then moved along into the esophagus. The esophagus is interesting since the food does not move by gravity like the other parts of the digestive system. It is moved little by little into the stomach due to rhythmic muscle contractions called peristalsis. Next up, the stomach is where all the magic happens, or at least I thought! Most people also think that the stomach digests all food but that is actually false. The stomach secretes gastric juice in efforts to turn chewed food into what is referred to as bile.This gastric juice is made up of hydrochloric acid, mucus, and other digestive enzymes. Accessory organs such as the pancreas, gallbladder and liver also deliver stored/recycled bile and digestive enzymes to stomach for insurance of smooth digestion. This digestive process takes around 2-6 hours until the bile is transported to the small intestine. The small intestine is where almost all of the digestion takes place in the digestive tract; especially in the duodenum. The duodenum is the very beginning of the SI and does around 90 percent of the breakdown of food in this organ. The rest of the SI’s job is to absorb nutrients from the bile and distribute it into the bloodstream.Villi in the small intestine are a big help when it comes to extracting nutrients considering they increase surface area. Then, the last organ to organ transfer happens when the now, watered down bile is moved into the large intestine. This organs purpose is to reclaim all the water in the soon to be feces. Once the water is absorbed back into the body, the feces is pushed into the rectum, and lastly released from the anus.
11. Kidneys are needed in order to complete the process we know as peeing. All vertebrae’s have two kidneys. Each individual kidney is a small, fist sized filtration system. Not only does it filter our urine, but it also filters our blood. This is important because it gives us internal stability, allowing the body to remain at a constant “norm” which is essential for a normal life. Do not make the mistake of thinking the kidney is one large filter, for it has millions of filtration units called nephrons that work together making ultimately a “super filter”. The two kidneys work separately but for the same purpose. Some of these purposes includes filtration, reabsorption, secretion, and excretion. Filtration is when liquid enters the kidney. It immediately gets filtered leaving out anything but water and smaller molecules. This excludes plasma and other bodily liquids that would be mixed in. Reabsorption is the process of the water and any other remaining valuable nutrition are returned to the blood where they further nourish the body. Secretion is somewhat the opposite concept from reabsorption. An extraction of specific unneeded substances in the blood is in process as it delivers it back into the tubule of the kidney. Everything from that point on is part of the excretion process. Anything that is leftover in the kidney is waste and needs to be removed from the body. This is why we pee, and urinating is the solution to eliminating theses wastes from our body.
12. Breathing is actually much more complicated than it seems. Humans see breathing as being broken down into 2 function; inhaling and exhaling. The internal work that goes into successfully breathing is actually more complex than it seems. People also believe the lungs are the only organ in play when it come to breathing. This is also found to be incorrect. The lungs along with a couple other accessory organs all take equally important roles in breathing. When we inhale, we intake oxygen into through our mouths/nostrils, into the pharynx. The pharynx is where the digestive system and respiratory system meet. When breathing, the pharynx knows to remain open to the appropriate tube, whether it be the “eating” or “breathing” tube. It then passes through the larynx, otherwise known as the voicebox. Next, the air travels past the Trachea aka windpipe, and becomes attached to tubes that lead into either side of the lungs called bronchi. Once the air is in the lungs, it gets closer to being converted into carbon dioxide. Each bronchiole in each lung goes into finer and finer tubing which ends with a cluster. This cluster resembles a grape bunch, and are a bunch of air sacs called the Alveolar sacs. These sacs are the most crucial element of breathing process. When oxygen goes into the each alveoli, it’s the alveoli’s job to make sure the oxygen that the being inhaled is nourishing the body, via the blood stream, as well as ensuring we exhale as well. What is it that we exhale if the oxygen is being used through out the body? The answer is carbon dioxide. Carbon Dioxide is the result of oxygen being used up internally. Carbon dioxide travels with the blood back into the lungs, where it is then released in the alveoli, and finally it is exhales though either way it came in; nostrils or the mouth.
14. diagram of the heart:
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9. Gregor Mendel is considered one of the most well known, advanced individuals for his time. He discovered multiple laws that explain how and why a offspring’s characteristics develop; looks and physical traits. One of these laws is the Law of Dominance which has more to do with appearance than any other law of Mendel’s. Dominant and recessive traits make up the physical characteristics or traits of an offspring and are determined by the kind of allele is put forth from each parents genes. A Dominant gene will always be seen in one’s physical traits, as a recessive gene would only be seen if both parents offer the same recessive allele. “Mendel’s law of dominance specifically expresses that if one parent has two copies of allele A for example—the dominant allele—and the second parent has two copes of allele a—the recessive allele—then the offspring will inherit an Aa genotype and display the dominant phenotype.” (Explanation of Mendel’s Three Laws Through Discussion Of Meiosis). A genotype consists of two lettered meaning of what the phenotype will look like. A genotype would be referred to as a heterozygous pair of alleles if they are different, for example, Aa. Homozygous is what a pair of alleles is referred to if the pair looks something like this AA or aa. A phenotype shows what the physical characteristics will look like in the offspring. Again, this is based off what alleles are presented in the genotype illustrate for the phenotype to display. Codominance is when there is no blending involved with the combination of dominant alleles from each parent. This means that both traits will be equally expressed in the physical characteristics of the individual. An example would be (horse diagram below)
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This is an example of codominance because both dominant color genes were distributed to the offspring, combining them to make a mixed, different color of the horse. Incomplete dominance is similar to codominance but instead of both dominant alleles being shown, both one recessive and one dominant gene are displayed in the physical traits of the offspring. An example could be a white cat and a brown cat mate and the result is an orange cat. When dealing with genetic condition, X-linked inheritance also known as X-linked recessive inherence mainly effect the male gender. They are more likely to be affected because men only have one x chromosome and one y chromosome. It is harder for an x-linked disorder to be placed upon a women because a female’s genes tend to be masked by the two x chromosomes in their genes. Men can not oppress the disorder due to the only 1 x chromosome.
http://education.seattlepi.com/explanation-mendels-three-laws-through-discussion-meiosis-3838.html
The scientific method revolves around multiple specific questions. In order, they start with the asking of a question. This is where the brain storming originates which then leads you to the second step in the scientific method; Research. Researching a topic/question does not always give you a direct answer or the answer you desire. This is why developing your own opinion is a significant part of the next step which is creating a hypothesis. An example of a hypothesis in scientific method would be if someone’s face was breaking out continuously and they hypostasized that if they stopped using their moisturizer, they would not break out anymore. What would be the next step to validate this hypothesis? Testing it! An experiment(s) are the only way to test if what was predicted is the true outcome. To continue this example, they would go through their normal skin routine minus the moisturizer only for a span of approx. two weeks. If that did not make a difference, or even had the opposite effect where it made the skin worse, it is time to trouble shoot. Trouble shooting in experiments is simply the attempt at fixing flaws in the procedure. This normally results in repeating the scientific method by re-hypothesizing using the new data. With or without trouble shooting, a conclusion must be drawn from the information collected within the trials. This is the next step, concluding and analyzing. This is where the tester must come to terms with failure or come to the realization that the experiment matched the hypothesis. The last step is recording the results of the trials as a whole, or in other words, it worked or it did not work.
8. The theory of evolution revolves around a evolution process called Natural Selection. Natural selection is a change of an a species that effects either physical or behavioral changes, sometimes both. Organisms with certain inherited traits are more likely to survive and reproduce than organisms with other traits. These changes although they are small, they change the color, size or other physical attributes of the species over the course of a few generations. The man who first thought of the idea is Charles Darwin, who wrote about this concept in his book, “On the Origin of Species”. Darwin explains that the “struggle for existence” is the reasoning behind natural selection. Due to the small percentage of animals that survive and thrive on their own, the instinctual fight will make any individual try its hardest to be the “best” for survival’s sake. A key observation of Darwin’s was noticing that no two people/organisms are exactly the same. Some can be similar copies of their parents. After multiple generations, things slightly changed within the species. Darwin explains these small changes in a few observations:
1) Over production and competition: the potential for a species to create as many offspring as they please automatically causes a struggle and competition for survival.
2) Individual variation: variation of heritable traits within a population
3) Unequal reproductive success: Those induvial best suited to their environment, leaving better chances of healthy, surviving offspring.
Fossils are also a great way of understanding the physical changes and evolution of all species bodies. Darwin also studied this theory, and named it decent with modification. Descent with Modificatoin is the remodeling of ancestral structures as they are modified to take on a new function. For example, skeletons of ancient snakes have been found with traces of leg and pelvic bones. If limbs like these provided a positive survival rate for snakes, they would still have them. Since they are not useful to this species, they evolve by descent of modification with smaller, more helpful limbs.