Biology Essays (Examples)

Filter results by:


According to LiveScience, biology is the “science of life.” While this definition of biology may seem very broad and all-encompassing, it is the best definition of biology that we have encountered. Biology is the science and study of life. However, when talking about biology as a course or class, it is both more and less than the science of life. Generally, it begins with the study of very specific structures, known as cells, which serve as the basic building blocks for life on planet Earth.

In fact, many introductory biology courses begin with an introduction to the basics of cell structure. Complex organisms contain a variety of different cells, while single-celled or simple organisms may contain only one type of cell. However, all of these cells share similar structures and engage in certain processes that show an underlying similarity between different types of life. Once you understand cell structure, then you can begin to understand cell functions. These functions include respiration, reproduction through meiosis and mitosis, and the cell cycle. While cell reproduction may seem basic, understanding it is critical not only to an understanding of how plants and animals create offspring, but also to understanding how diseases like cancer proliferate in the body.

While biology once considered cells the crucial building block of life, a growing understanding of DNA and RNA demonstrate the critical role that four base chemicals play in structuring life. DNA is composed of adenine, guanine, cytosine, and thymine. RNA or ribonucleic acid is created by the DNA to carry messages to proteins. These messages can critically impact cellular functioning. While much is known about both DNA and RNA, scientists are making new discoveries on a daily basis. These discoveries, in turn, impact other areas of biology.

Another goal of biology is to describe living organisms, and, to do this, biologists often classify plants and animals. This classification is referred to as taxonomy. Taxonomy starts with a broad group, like plant or animal, and then continues to narrow down options. From the broadest to the narrowest, these groupings are: domain, kingdom, phylum, class, order, family, genus, and species. However, taxonomy is far from an exact science, and there may be substantial disagreement about whether animals constitute different species or subspecies.

Introductory biology often divides organisms into two broad groups: plants and animals. Then, it provides a cursory introduction into these two basic types of life. While the definitions of plant and animals may seem self-explanatory, there are some organisms that show characteristics of both plants and animals, which can make classification difficult. That is why biology also focuses on understanding some of these in-between microorganisms, like: monera, Protista, fungi, and viruses.

However, the overlap between certain organisms in either group help explain the process of evolution. Although the topic of evolution has been a hot-button political issue since as far back as the Scopes Monkey Trial, the term evolution merely describes the process by which species characteristics change over time through the process of natural selection. Evolution is frequently called Darwinian evolution because the process was first described by the naturalist Charles Darwin

View Full Essay

How Does the Brain Work

Words: 533 Length: 2 Pages Document Type: Essay Paper #: 20934065

Brain Functions
Terminal buttons are on neurons and form the small balls at the end of the axon where chemicals are released. These chemicals are neurotransmitters. Thus, the terminal button acts as the presynaptic neuron of the synapse.
The myelin sheath is a layer of insulation that covers nerves in the brain. It consists of protein and fats, which allow electrical pulses to pass through and on to the nerve cells. The myelin sheath thus protects the nerves in a way that allows messages to get through.
The axon are nerve fibers that look like long, hairs on a nerve cell. They are like the antenna of the neuron, and conduct electrical pulses away from the soma. Axons act as the transmission lines of the nervous system.
The axon hillock is part of the soma that connects to the axon. It is the last point in the soma where membrane…… [Read More]