POLYMORPHISM:
The phenomena of the presence or existence of different morphs or phenotypes in a particular species belonging to a particular population at the same time and place is called polymorphism. The morphs should be present in frequencies high enough to be noticed readily. Polymorphism is usually the result of mutation.
Salient features of polymorphism:
1. Polymorphism is the presence of more than one phenotypes of a species due to two or more genotypes resulting from usually mutation.
2. Different morphs are adapted to different environments.
3. All Mendelian populations are polymorphic.
4. Polymorphism helps a species to utilize natural resources from the environment more efficiently.
5. Polymorphism enables a species to get adapted in different environments.
6. Polymorphism helps the species to survive in different and hostile environments.
Types of polymorphism:
Different types of polymorphisms are present in nature such as-
1. Transient polymorphism.
2. Balanced polymorphism.
3. Geographic polymorphism.
4. Chromosomal polymorphism.
5. Single nucleotide polymorphism.
Every types have their unique characteristics. Here the top four are our topics of discussion and they will be described in this document.
TRANSIENT POLYMORPHISM:
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Transient state is actually an intermediate and short durable state. As the overexpressed gene replaces its native type, this phase ends. At the beginning when polymorphism was defined for the first time, it was thought that all kinds of polymorphisms are belonged to balanced polymorphism only until transient polymorphism came out as it has very distinguishable and unique characteristics than all other forms of
It is really interesting to break down the separate classes and find their similar details and their different details. Obviously the differences are greater in number and some of them fairly extreme. But that is to be expected.
The major topic of this experiment was to examine two different crosses between Drosophila fruit flies and to determine how many flies of each phenotype were produced. Phenotype refers to an individual’s appearance, where as genotype refers to an individual’s genes. The basic law of genetics that was examined in this lab was formulated by a man often times called the “father of genetics,” Gregor Mendel. He determined that individuals have two alternate forms of a gene, referred to as two alleles. An individual can me homozygous dominant (two dominant alleles, AA), homozygous recessive, (two recessive alleles, aa), or heterozygous (one dominant and one recessive allele, Aa). There were tow particular crosses that took place in this experiment. The first cross-performed was Ebony Bodies versus Vestigle Wings, where Long wings are dominant over short wings and normal bodies are dominant over black bodies. The other cross that was performed was White versus Wild where red eyes in fruit flies are dominant over white eyes.
In conclusion table 10-1 on page 292 list the three types of models. These models provide
[7] Klug, W., Cummings, M., Spencer, C., Palladino M. (2012) Concepts of Genetics: Tenth Edition. Pearson's Education, Inc.
The third part of the evolution theory is speciation. Speciation means that different groups of creatures that cannot exchange genes with one another cannot interbreed with one another.
Biological Trait Theory has been found to have influences in neurophysiology, or the way the brain’s nervous system functions. When the part of the brain that controls fear, aggression, and social interactions, the amygdala, occurs in lower volumes, these traits will appear later in someone’s life. Other research cases have shown that psychopathic behaviors can occur when an individual’s amygdala functions at a lower efficiency or has certain deficits. One study, led by Yu Gao of the University of Pennsylvania, suggests that tendencies that may indict this event can occur before any crimes are committed. Another part of the brain, the anterior cingulate cortex, or the ACC, which plays an important role in controlling behavior and impulses,
In the 19th century, Mendel’s relatively new science of inheritance and hereditary has increasingly developed into what we commonly understand today as genetics. Peter J. Bowler describes this field as becoming “a very active area of scientific research”.
We have known for centuries that traits are passed from parents to offspring. What has not always been understood is how traits are determined. One explanation that appealed to scientist for many centuries was that traits of parents were blended, or mixed in offspring. The blending hypothesis accounted for many observable traits and was widely accepted for many years. However, the idea of blending could not account for the appearance of unexpected traits in some offspring. It was not until scientist discovered the cellular basis of life that the inheritance of traits was better understood.
There are many aspects to include when defining diversity. Diversity is understanding biological variations, space, social organization, communication, time and environmental control of a culture. The first aspect is understanding the different biological variations within different cultures of people. Biological variations include: body structure,
In the following table is a brief look at the four theories that will be highlighted in this paper and how they compare to each other:
Darwin explain that, excepting for two reasons, variability cannot be distinguish from species. The first is by the discovery of intermedate ways of linking, and the other explains that by certain indefinite amount of differences between them; this mean that if the differences are few, are considerated and classified variabilities inside the same
Many scientists in the past, such as Aristotle and Plato, believed that there were no changes in populations; however, other scientists, such as Darwin and Wallace, arose and argued that species inherit heritable traits from common ancestors and environmental forces drives out certain heritable traits that makes the species better suited to survive or be more “fit” for that environment. Therefore, species do change over a period of time and they were able to support their theory by showing that evolution does occur. There were four basic mechanisms of evolution in their theory: mutation, migration, genetic drift, and natural selection. Natural selection is the gradual process by which heritable traits that makes it more likely for an organism to survive and successfully reproduce increases, whereas there is a decline in those who do have those beneficial heritable traits (Natural Selection). For example, there is a decrease in rain which causes a drought in the finches’ environment. The seeds in the finches’ environment would not be soft enough for the smaller and weaker beak finches to break; therefore, they cannot compete with the larger and stronger beak finches for food. The larger and stronger beak finches has a heritable trait that helps them survive and reproduce better than others for that particular environment which makes them categorized under natural selection (Freeman, 2002).
Each type involves different conceptualizations, instrumentations, and preparations and each type involves somewhat different purposes (Patton,
When the F1 generation are heterozygous for each trait, the known outcome of the monohybrid cross for the F2 is a 1:2:1 genotypic ratio, which represents the heterozygous and homozygous (dominant and recessive) alleles, and a 3:1 phenotypic ratio where the dominant trait is present three times as much as the recessive