Carbon cycles through the ecosystem between the atmosphere, organisms (such as producers, herbivores, and carnivores) and decomposers. This natural cycle maintains a somewhat constant level of carbon in the atmosphere. The burning of fossil fuels releases carbon into the cycle that has been trapped inside the earth. How does this affect the cycle and what problems can this cause?
The two main processes of the carbon cycle are photosynthesis and metabolism. Plants and animals consume and express carbon dioxide in relatively equal measure. Human beings affect this fragile process by releasing fossil fuels into the atmosphere which produces surplus carbon. Those who support the concept of global warming argue that these surplus carbons, along with other greenhouse gases, are increasing the temperature of the planet (Kasting 1998).
Carbon naturally is in balance between released and stored materials. As carbon is released by the burning of fossil fuels, the locations for storage are being used up and thus higher percentages of carbon are being released into the atmosphere. Scientists argue that if fossil fuels are burned, the potentially consequences include tripling the current amounts of carbon dioxide in the atmosphere (Kasting 1998). This could potentially create an atmosphere which is no longer breathable by human beings and other mammals. Other potential consequences of the burning of fossil fuels could include the melting of glaciers and the elevation of sea level. This could lead directly to draughts which would then destroy crops and diminish food supplies.
2. Using Darwin's reasoning, explain how four species of lizards, all closely related, came to be separate species on a Caribbean island.
Darwin's theory was that mutation occurs every so often in a species. If this variation proves to be beneficial to the creature, then subsequent generations will be born with this adaptation. Subsequent generations will increase the strength of this differentiation, leading to a complete change in the species. Usually those with unsuccessful adaptations will not survive. Sometimes the adaptations lead to a division between two creatures. They will have slightly dissimilar mutations, both of which are successful. Their descendants will have more obvious versions of these adaptations until the two creatures, once a part of the same species have diverged and become completely different from their common ancestor.
The process of divergent adaptation, what is commonly called evolution, takes millions of years. Darwin believed that some species were closely related but still separate entities. The explanation for this could only be that they descended from a common ancestor (Postlethwait 2009). As the environment of a location changes, the creature must adapt or be unable to survive in the new climate. On one Caribbean island, several different species of lizards exist. This is explained by the unique adaptation which begins to separate similar creatures within the same generation. On the Galapagos Islands, Darwin discovered several variations of finches. Each different type had adaptation which better equipped them for certain tasks and determined how they fed and where they nested. All the birds, he determined, were descended from the same ancestral creature but became new types through millions of years of adaptation and change (Losos 2011).
3. During interphase the DNA is not visible through a microscope; it only becomes visible as chromosomes during mitosis. Why isn't the DNA visible during interphase and why would this be the case?
During interphase, the DNA is not visible because during this phase, the DNA is not condensed. DNA by itself is not visible, even with the use of a high-powered microscope. The only times that DNA can be seen are when the DNA is compacted and condensed (Herreid 2004). Scientists never see a single piece of DNA. Rather, they can see groupings of DNA when they are condensed.
It is during this phase that the DNA is being used in the process of protein synthesis by transcribing mRNA. This phase is important because the DNA is performing many processes which are necessary for the continuance of life (Herreid 2004). Since it is constantly in motion, the DNA is never still for a long enough period to condense and become visible.
4. How is it that, in meiosis, you can end up with four "daughter cells" that are all genetically different from one another?
During meiosis, there is a process called independent assortment. This means that at the end of meiosis, the cells produced can be very different from one another. When this process overlaps with metaphase, exchange of cellular information can occur wherein the four daughter cells that are produced are completely different from one another (Escobedo 2005). Meiosis is completely dependent on the exchange of information during cellular reproduction.
There is a different between meiosis and mitosis. In meiosis, information of cells can be exchanged randomly and can be parceled out differentially. Part of the reason for this is that meiosis produces haploid cells which only contain half the genetic information of their parent cells (Escobedo 2005). Mitosis is direct reproduction of cells wherein the daughter cells will be identical to the parent cell.
5. Use Punnett squares to illustrate whether a type A female and a type B male can have a child with type O blood.
In the above Punnett square, it is proved that two parents, one with blood type A and one with blood type B can produce a child with type O blood. Type O blood is caused by a recessive gene, meaning that if there is another type present in the genetic code, the other gene will dominate and the person will possess the traits of the dominant gene (Genetics 2006).
If the mother's blood type had genetic markings of A and O, her blood type would register as A, but she could still give off an O. blood type marker to her offspring. A would be the dominant gene and so she would have A type blood, but she could still give an O type marker to her child. Similarly, if the father had genetic markings of B. And O, his blood type would be B, but he could provide his children with either a B. Or an O. bloody type marker. If both parents gave off their O. markers, then the child could have blood type O. However, if either parent had a homogenous blood type, such as AA in the mother or BB in the father, then they could never have an offspring who possessed O type blood.
6. Your friend Gorinda wants to know if there are ever mutations that don't cause problems. What do you tell him?
I would tell Gorinda that mutation is the very basis of evolution. Species adapt on the genetic level to changes in their environment. All mutation means is a change in the body which changes something within that body. Some examples of positive mutations include adaptation to temperatures, adaptations to new chemicals or materials within the atmosphere, and adaptations to help avoid predators (Myers 2011).
There are negative forms of mutation, such as changes which in the body like cancers which are harmful. However, saying that all mutation is problematic is overlooking the very basis for the evolution of beings. Human beings, for example, have become adapted to certain diseases through generations (Harter 1999). One such example is influenza. Less than a century ago, people were dying of the flu. Nowadays people have mostly adapted to the strain and are able to overcome the disease.
7. Compare DNA to a cookbook. The book is kept in a library and cannot be checked out (removed). Start with the letters and words in the cookbook compared with the bases and codons in DNA; end with the amino acid chain being folded into a protein, and a cake being baked.
All creatures are made from genetic material, referred to as DNA. How to make a being requires steps similar to a recipe in a cookbook. The first step is to acquire all the ingredients. For each offspring, a parent or parents is required. If there is only one parent, then the DNA from the one will separate and the product will be the same as the original. If there are two parents, then each one will provide half of the ingredients of the recipe (Freudenrich 2011). Mom will give her genes and dad will give his as well. These are mixed together in a bowl and the dominant genes decide the ultimate flavor of the recipe.
In the given scenario, since the book cannot be removed from the library, then the necessary recipe must be duplicated in some way. DNA also requires duplication in part. This part, the RNA must be duplicated. To make the food of the recipe, you have to get all the ingredients as stated above. Then you need to add them in the correct order. The amino acid chain of DNA must be placed in the right order if the strand will be used to create a being. Finally, the molecules…