Writing in Biology

In a 6-year observational study conducted by Thompson and Cunningham (found in 2002 Nature), it was found that the Greyamoth benefits the Lithophragmaflower by pollinating it only when other pollinators are present. The moth lays its eggs on the flowers and the larvae eat the seeds of the flower, but when other pollinators are present, it provides competition for the moth so that there are not an excessive amount of moths pollinating the flower. In short, the nature of an interaction (mutualism or antagonism) depends on who else is in the community.

A proposed study with subjects experiencing some degree of neuropathy may require a smaller sample size. This study did not have a supervised control group meaning that the exercise group received more face to face time with the investigators and they received information from a qualified physical education instructor. The study also did not include any resistance exercise and the subjects that were tested showed no signs or symptoms of DPN. Measured motor and sural sensory nerves using a Medelec MS 928 Neurostar. Measured the nerve conduction velocity as well as the nerve action potential amplitude. Vibration perception threshold was tested by using a Biothesiometer and the vibration amplitude was increased until the patient could feel it.

Speciation is the second most important evolutionary process in birds that is responsible for evolution. It is more common in Aves classes (all birds) mainly because they can geographically isolated from their original population due to migration. Allopatry causes isolation, which can occur under certain conditions. Allopatry can cause species to migrate from one place to the other and it prevents gene flow between species. Since species are migrating there is no genetic interchange between them. Various geographic changes can cause species to isolate such as movement of continents, glaciers, formation of mountains and islands. Human activity such as agriculture and deforestation can also cause species to isolate.

The EGFR/KRAS pathway, commonly mutated in pancreatic adenocarcinoma, is a promising area of focus for targeted tumor treatment. A point mutation in codon 12 of the KRAS oncogene is nearly ubiquitious to all pancreatic adenocarcinomas. Targeted therapies would need to specifically focus on this mutation in the cancerous cells without damaging the growth pathway in normal, healthy cells. A possible therapy that may accomplish this goal includes a microRNA with a complementary sequence for the point mutation, which would allow it to bind to only cancerous cells. After binding, expression of the EGFR/KRAS pathway would be blocked by either degradation of the mRNA or by blocking translation through a ribosome. A challenge that remains is introducing this interfering RNA into cancerous cells. Liposomes may serve as useful areas for transport inside the cell after binding to cancer-specific antigens on the surface.

There are four main types of biomolecules: carbohydrates, proteins, lipids, and nucleic acids. These biomolecules make up the cells that make up organisms and are responsible for the mechanisms within the body. Carbohydrates are composed of carbons, hydrogens, and oxygens. Monosaccharides bond to form oligosaccharides that can be bound to cell surface proteins to aid in cell signaling. Proteins are made up of amino acids, which are composed of a central carbon bound to an amino group, a carboxyl group, and a variable "R" group. The R group can be nonpolar, polar without charge, negatively charged, or positively charged, and the polarity of the R group will influence how different amino acids interact intramolecularly or intermolecularly with other molecules. On the other hand, lipids are made up of mainly hydrocarbons and are therefore insoluble in water. The saturation of different lipids vary, affecting the solidity of the lipid at room temperature. Fully saturated lipids have carbons saturated with hydrogens, while unsaturated lipids have double bonds between carbons, resulting in less surrounding hydrogens. Lastly, nucleic acids are composed of nucleotides that consist of a sugar ring, a phosphate group, and a nitrogenous base. The most recognized nucleic acid is DNA, and in DNA, nucleotide phosphate groups and sugars form phosphodiester bonds that make up the sugar-phosphate backbone. The nitrogenous bases form hydrogen bonds across the two strands of DNA to form the DNA ladder.

It is surprising to see how many similarities fish have with all other vertebrates considering how different they physically appear to be. One of these similarities is their bony skeleton that also consists of a skull which is something that is found in both vertebrate and fish. Fish have been present for around four hundred million years as opposed to mammals who have been around for 200 million years. Although they have been around for drastically different times their similarities do start after conception. A piece of evidence of evolution can be found in an embryo. All animals start their earliest development the same way, as a single cell. A fish embryo and a human embryo look almost identical with one another. Small ridges can be found in both of embryos in fish they develop into gills and for humans they become the portion of the lower jaw as well as middle ear and voice box. To bridge the gap between land animals and water animals a Tiktaalikfossil can be examined. Although fish do not have necks they can be found in the Tiktaalik, although it is an extinct fish it had many features of a tetrapod. Including the bone ratio of one bone, two bones, little bones that is also found in humans which is why this animal helps fill the gap.

Schizophrenia can be described as a disorder which leads the victims to have faulty perception, inappropriate actions and feeling, withdrawal from reality and personal relationships, and difficulty distinguishing between what is real and what is just his or her thoughts.  “Schizophrenia affects about 1% of the world population. In the United States, about 2.5 million people have this disease, about one in one hundred people. Symptoms usually appear between the ages of 13 and 25, but often appear earlier in males than females.” (Bellenir) Two types of symptoms for this disorder are positive and negative. Symptoms for this disorder include hallucinations, disorganized speech, agitation, as well as disorganized behavior. (Schizophrenia Symptoms) There are a few types of schizophrenia these are paranoid schizophrenia, disorganized schizophrenia, catatonic schizophrenia, undifferentiated schizophrenia, residual schizophrenia, and schizoaffective disorder.

Tiktaalik is a genus of extinct lobe-finned fish. As Tiktaalik roseae is the only species classified under the genus, Tiktaalik can be called a monospecific genus. It lived about 375 million years ago, during the Late Devonian Period. Although Tiktaalik generally had the characteristics of a lobe-finned fish, it also shared some traits with tetrapods: it had gills, scales, and fins, but it also had a robust ribcage, primitive lungs, and a mobile neck. Tiktaalik is often referred to as a “transitional fossil” because it also had intermediate features, such as half-fish, half-tetrapod limbs and joints with functional wrist joints and radiating, fish-like fins instead of toes. It also had an ear region that was half-fish, half-tetrapod. While it is not an ancestor to any currently living animal, Tiktaalik is evidence of animals with intermediate forms that bridged the evolutionary gap between fish with fins and animals with arms and legs.

Most species of birds evolved in isolation called allopatry under certain conditions. Isolated islands of habitats on continents set a similar stage for speciation of bird populations that they occupy. Sister populations that were separated and isolated geographically space diverge from each other. Divergence can either be slow or rapid. Conspicuous patterns of geographical variations are the result of divergence and it can also be random which follow adaptation to different habitats and can results from sexual selection.

Land mammals have different forms of stances. The main three catagories are plantigrade, digitigrade, and unguligrade. Plantigrade means that animal's heal touches the ground as it moves and usually indicates an ambulatory or walking way of movement. Examples of plantigrades are bears, apes, and humans. Digitigrades are animals that stand on their toes or digits when the walk like cats and dogs. They are usually more of a cursorial or running motion. Lastly unguligrades are animals that move on their hooves or toenails, featured in cursorial moving animals like horses and deer.