Essays on Genetic Variability

Drugs can have many differing affects on people, whether their consumption leads to a positive or adverse response. All of this depends on the levels of enzymes in the body and how the variations of expression lead to these possible outcomes. The major theme of the two sources on this topic relate to the specific enzyme, CYP3A. CYP3A is a subfamily of cytochrome P450 enzymes, which serve to catalyze the addition of oxygen into molecules. Their ultimate role serves two spectrums: to convert foreign substances into less toxic products that can be eliminated from the body, or to convert ...

Corridors and Population Dispersion

Part I. Introduction and Review of Relevant Biology

1. Energy transfer becomes inefficient in higher trophic levels in a food chain. Predators utilize more energy in obtaining food than their prey. The number of organisms and the amount of biomass defines energy relationships among organisms in trophic levels. Most top predators are huge in size but their population is lower because there is not enough energy to support a large population of these predators (Odum and Barrett).

2. A population of infinite size is seen less likely to evolve since it would be almost resistant to random fluctuations within the environment. Small populations on the other hand are prone ...

Asthma is a respiratory disorder that affects the respiratory airways. It is characterized by inflammation and subsequent narrowing of the air passages. It leads to episodes of wheezing, coughing, dyspnea and chest tightness. It mostly occurs in the night or in the early morning hours. It may affect people of any age, but commoner in young children. In the United States, there are approximately 25 million asthma patients, out of these, 7 million are children (National Heart, Lung, and Blood Institute, 2015). In this paper we will discuss about a 15 years old boy who is diagnosed with asthma. We ...

Evolution of Sexual Reproduction

There are different forms of reproduction, which includes vegetative, asexual, sexual reproductions. Naturally, the question arises, what are the benefits of sexual reproduction in terms of fitness of a species, and how does it compare to other forms of reproduction? Logically, females reproducing asexually are more likely to have twice as many grandchildren and can increase their fitness two folds(Hurst and Peck). On the other hand, by reproducing sexually, both sexes have to invest copious amounts of time in selecting mates, making nests, bringing up offspring etc. In this paper we will try to understand the benefits and disadvantages ...

Properties of Life

When it comes to dealing with cells as a structural and functional unit of all kinds of life on earth, it is important to understand the biological concept of what constitutes life. Most biologists, including cell biologists will agree that life is defined according to seven principles. First, that living things are composed of cells. A cell is a unit that makes up all kinds of life, whether it is a bacterial life or plant life or human life. The second principle is that there are different levels of organization in life – cells make up tissues, tissues make up organs, and so ...

The model of complete replacement by Christopher Stringer and Peter Andrew states that 200,000- 150,000 years ago the archaic humans evolved to the modern humans in Africa and then later migrated to other parts of the world replacing the Neanderthals around 60,000 -40,000 years ago. This theory suggests that all people have an African ancestry (Kuklik & Henrika, 28).It also argues that all other forms of Humans like Homo erectus have gone extinct. It suggests that the developments seen in humans today are recent. Regional continuity model also known as multiregional evolution model by ...