Nida, Daphne and Sara's Effect of Environmental Stimuli on Cell Division Arguement

Rana, Jube, and Rameia's Effects of Environmental Cell Division Powerpoint Argumentation

Joshua, Chigozie, and Jazmean's Effect of Enviornmental Stimuli on Cell Division Argument

Daphne's Virus Argumentation

When attempting to define whether or not viruses are living creatures, it is important we consider what it truly means to be alive. In order to qualify as a living, a being must possess all of the following characteristics:

1. Living things are composed of cells
2. They possess different levels of molecular/cellular organization
3. They take in energy to use for maintenance and/or growth
4. They respond to stimuli presented by their environments
5. They reproduce, sexually or asexually
6. They experience growth
7. They adapt to their environment over time (as a species) through evolution

Because of these standards, viruses cannot be considered to be alive. When scientists crystallized the tobacco mosaic virus, they determined that the virus lacked the genes for metabolism. This indicates that they do not take in energy for maintenance and/or growth. Since it takes just one of these qualities being absent to disqualify something from being alive, viruses cannot be considered living. Furthermore, viruses cannot reproduce on their own.  When not in contact with a host cell, viruses are no more active than free organic matter. In this state, they are inactive and no internal biological activities occur within the virus. Viruses consist of no more than membrane-bound DNA or RNA. Only when they infect a host cell are they able to multiply and divide through the lytic cycle. In order to be alive, organisms must be able to reproduce on their own. Also, viruses do not respond to stimuli in their environments, which is another factor required for living creatures.
People (especially scientists) like to create organized categories and imagine that all of the world fits into them, checking off all the boxes. Such is not necessarily the case with viruses. They almost straddle the definition of life, seeing as they do not check off some of these qualifications. However, they seem to possess lifelike qualities, which is what makes classifying them so difficult. As far as classifying them by the preset standards established by scientific laws, viruses are most definitely not alive.

Chigozie's Virus Argumentation

Viruses: Living or Non-Living?

            Viruses should not be classified as living things simply because they do not have all properties of living things on their own. There are seven characteristics that living things must possess. Living things are composed of cells, have different levels of organization, use energy, respond to their environment, grow, reproduce, and adapt to their environment. Technically, if an organism does not have all of these properties, then it cannot be considered a living thing. Viruses exhibit some characteristics of living things only when attached to a host. Because of this, viruses cannot be considered living things.

            For example, Adenovirus cannot be considered a living thing. According to the chart, Adenovirus does not have all of the characteristics of living things. It does not use energy or carbon or respond to external stimuli (its environment). It also does not grow. It does, however, have biomolecules (nucleic acid, proteins, and lipids) and RNA present, giving it some type of organization. Adenovirus also reproduces, but reproduction requires a host. Although Adenovirus has two characteristics of living things, it still cannot be considered a living thing. Again, Adenovirus has to possess all of the characteristics of life in order to be classified as a living thing.

All in all, viruses should not be classified as living things. They lack many of the properties that are used to identify living organisms. The main characteristic that viruses lack is reproduction; they cannot reproduce without the assistance of a host. Because viruses do not have all seven characteristics of life, they are not to be considered living things.

Rana's Characteristics of Viruses Argumentation

Virus Argumentation - Should a virus be classified as a living thing?

Viruses should not be classified as living things.  In order for anything to be considered living it must have all of 7 characteristics.  All living things are composed of cells, have different levels of organization, use energy, respond to stimuli, grow, reproduce, and adapt to their environment.  Viruses however, only contain few of those characteristics.  They have biomolecules, can reproduce, and have genetic material.  This is not sufficient enough for them to be classified as living. Table 1 shows many different objects and their characteristics.  Only the living things contain at least one of every characteristic in the table, while the non living things are missing at least one of the characteristics.  Some of the living things in this table are, sponges, elodea, plasmodium, e. coli, tube worms, and dogs.  Each of them have an energy source of either the sun, organic compounds, or inorganic compounds.  They all have a carbon source of either carbohydrates, or carbon dioxide.  They all have a waste production, respond to external stimuli, have all 4 biomolecules, a form of reproduction, genetic material, and they grow.  All of these that they contain are necessary for any organism to be labelled as living.  

Viruses may enter cells, infect cells, and reproduce inside cells, but in no way are cells.  Viruses are tiny bundles of genetic material, either DNA or RNA, and are carried in protein shells called capsids.  Genetic material is the molecule that plays the fundamental role in determining the nature and structure of an organism or cell.  All living things contain genetic material, viruses as well, but the genetic material would lie within the cells and viruses do not have and are not cells.  Also, the genetic material inside the virus is not activated until the virus is inside a cell.  Once a virus enters a cell, the cell itself will create more copies of the virus.  Which also shows that viruses cannot reproduce.  Living things reproduce in order for their species to survive, but they only reproduce either asexually or sexually.  Asexual reproduction is to produce offspring without the use of gametes, while sexual reproduction is producing offspring by joining sex cells.  As seen in table 1, viruses such as the influenza virus and the adenovirus only replicate, and require a host in order to do so.  Furthermore, the use of energy is important in all living things, it is used for maintenance and growth.  According to table 1, viruses such as the influenza virus and the adenovirus do not contain any energy source, meaning that they do not produce or use energy.  Living organisms also respond to their stimuli by making changes in response to their environment.  Both the influenza and the adenovirus do not respond to their external stimuli.  In order to be living they also should grow through cell division.  However, since viruses do not contain cells and are not cells, they can not grow either.

Unlike viruses, the sponges, elodea, plasmodium, e. coli, tube worms, and dogs are all living things that contain the necessary characteristics of life.  They all have an energy source for maintenance and growth.  The energy is used for internal processes such as photosynthesis.  Also, they all have a carbon source, which is to gain carbon because it is an essential atom used in the formation of molecules such as the 4 biomolecules: nucleic acids, proteins, lipids, and carbohydrates.  The nucleic acids make up the genetic material contained in all living organisms, both DNA and RNA.  In order to maintain homeostasis, they each all have a form of waste production, and in order to adapt and change according to their environment they each have the ability to respond to external stimuli. Lastly, they all have either sexual, asexual, or both as their form of reproduction in order for their species to survive.   

Even though an object may contain some characteristics that may classify it as living, if it does not have all of the characteristics, it is not living.  Similarly, a computer, which is also in table 1, does have an energy source, waste production, and responds to external stimuli.  However, it is obviously known that it is also not living, but it still contains some of the same characteristics as other living things.  Likewise, viruses are not living things though they may contain biomolecules, a form of reproduction, and genetic material.  Since viruses do not have an energy source, a carbon source, waste production, response to stimuli, or growth, they are not living.  

Jazmean's Virus Argumentation

If we follow the standards set by scientists that constitute organisms as living, we cannot classify viruses as living things. Scientists use seven standards to determine if an entity is living: are they made up of cells, do they have levels of organization, can they obtain and use energy, do they grow and develop, can they reproduce, do they respond to their environment, and can they adapt to their environment. If an organism does not meet all of the seven qualifications, they are considered to be nonliving. Viruses only meet two of the seven qualifications: they can reproduce and they can adapt to their environment. And even though they meet these two qualifications, they cannot reproduce nor adapt to their environment without a host cell. This means that viruses are not independently efficient unlike other organisms such as Amoebas and Algae because a majority of their survival depends on their host cell.  Most scientists consider viruses outside of their host cell to be dormant and not functional.

Viruses do not conduct chemical or metabolic processes within them. They are not able to produce energy like plants and they are not able to use molecules like glucose to undergo cellular respiration like animal cells. They have no organelles that can help them do that. They only possess genetic information that is used to produce more viruses. They are not able to use their genetic information by themselves. Viruses have to employ the use of a host cell in order for the genetic information to be put to use. They also do not have the ability to respond to external stimuli when outside of their host cell.

 Because viruses are not able to meet all of the qualifications of what makes a living thing living, they are not able to be classified as living things.

Rameia's Virus Argumentation

Should Viruses be Considered Living Things?

Rameia Ramsey

          In order to be classified as a living thing there are seven characteristics that must be possessed by an object. A living thing must be composed of cells, there must be different levels of organization, it must use energy, it must respond to its environment(stimuli), it must grow and develop, it must be able to reproduce, and it must be able to adapt to its environment.  These seven characteristics make up a living organism.  Based off of these characteristics and the information provided in the data table I come to the decision that a virus should not be classified as a living thing.  A virus should not be classified as a living thing because they do not contain all of the properties that are associated with living things and would not be able to function properly without the aid of a host cell. 

          All living things must be composed of cells, a virus automatically violates this characteristic. A virus is a tiny bundle of genetic material that is carried in a protein shell called a capsid. Some viruses have an additional layer around the coat called an envelope that is made of a lipid. A virus in no shape or form is composed of cells. It is simply a bundle of DNA or RNA. This shows how a virus does not have all the characteristics needed to be a living thing

          A virus can also not be considered a living thing because it has no energy source.  On the data table the Influenza Virus and the Adenovirus are listed with having an energy source as none. Living things need an energy source to be able to take in energy and use it for maintenance and  growth. As a comparison on the chart listed is a plant called Elodea.  This plant uses the sunlight as its energy source. With the aid of sunlight this plant is able to carry out the photosynthesis in order to make itself food and help it grow and develop.  Viruses do not have an energy source which is why they rely on host cells to help them function. Host cells allow viruses to carry out their destructive behaviors. Since there is no actual source of energy aiding the virus in  developing and growing it is not a living thing.

          A virus will not respond to external stimuli which  makes it unfit to be a living thing. If we compare the Influenza Virus and the Adenovirus with another organism on the chart such as the Coriander Seeds we can see that a virus is not able to respond to stimuli. If the Coriander seed comes into contact with water or sun it will respond to that stimuli by growing. Living things will make changes in response to their environment but a virus does not change. Its form will always stay the same, without a host cell a virus won't do anything. Therefore it can not be classified as a living thing.

          Reproduction is not important for a living thing to survive by itself, but it must reproduce in order for a species to survive. Living things either reproduce sexually(joint of sex cells) or asexually(without the use of gametes) . Viruses can not reproduce by themselves, there needs to be a host cell for a virus to reproduce.  The Influenza Virus and Adenovirus use its host cell to survive. When those viruses enter its host cell the genetic material that it carries allows the virus to force the now infected cell to make copies of the virus. Without this host cell a virus can not reproduce to survive.  Other organisms on the chart such as dogs are able to reproduce sexually and create more offspring, if that one individual dog doesn't reproduce it will not harm it but if that one virus does not have a host cell it will not reproduce at all and become stagnant.

          Another reason why a virus should not be classified as a living thing is because it does not grow.  Living things grow through the process of cell division and cell enlargement.  As an organism gets larger the number of cells it contains increases. As I already established, viruses are not composed of cells, this means that they do not have the ability to grow.  A virus needs a host cell to grow, a virus by itself can not grow at all. As a comparison, the dog that is depicted in the chart is able to grow.  As the dog carries out its life cycle it grows and developed from a puppy into an adult dog. Viruses do not have the capability to grow and develop by itself, thus making a virus not a living thing because it lacks the ability to reproduce on its own.

          Viruses should not be considered a living thing because they lack many of the properties that make up a living organism.  As stated on the chart the Influenza Virus and he Adenovirus do not have an energy source, not respond to stimuli, can not reproduce without a host cell, and can not grow.  Without a host cell a virus can not do anything and is no harm or threat to anyone or anything. Its the host cell that allows the virus to function properly. Not possessing anyone of the characterizes makes something unfit to be living and the fact that a virus lacks several of these properties is proof that a virus should not be classified as a living thing.

   

Jube's Virus Argumentation

My evidence supports my claim because many viruses don’t fit the description of a living thing. Living things must be made up of cells, have the ability to grow, reproduce independently, respond to stimuli, eliminate waste products, and adapt to their environment.  Many viruses many have characteristics similar to that of a living thing, but if it does not have all of the characteristics, it cannot be considered alive. Living things are defined by their specific functions and processes, and viruses act as their inhibitor as they work to attack the normal functions of living things.

For instance, the influenza virus cannot be considered a living thing (according to the chart). It has no energy source, it produces no waste products, and it cannot respond to external stimuli. It also has no source of carbon. As a result, the virus has no was of carrying out metabolic processes such as cellular respiration as carbon is a vital element of life. Although this virus has nucleic acids and protein, its lack of lipids and carbohydrates does not allow it to be classified as a living thing. Lipids are vital as they store energy for the cells. Without lipids, the cellular membranes would not be flexible, and the cells would not be regulated in an efficient manner. Furthermore, the influenza virus lacks the ability to reproduce independently. Living things must have this trait in order to be considered alive. However, this virus uses replication to “reproduce”. It requires a host to replicate. By settling on a human host cell, it is able to attack it, and replicate as it travels its path. This makes the virus dependent on its host which is not a characteristic of a living thing. To add, living things must be able to adapt to changes in their environment. However, viruses typically do not adapt to their environments. They tend to invade the systems of other living things, and they work very systematically. They do not alter their structure and functions according to their environments as they attack.

In contrast, a dog can be considered a living thing (according to the chart provided). Dogs get their energy source from organic compounds. Organic compounds contain carbon which allow dogs to carry out metabolic processes such as cellular respiration. Since dogs have a source of carbohydrates, they can use their metabolic processes to break it down to form energy as carbs provide a source of ATP. To add, they are made up of all of the four main biomolecules of life (nucleic acids, protein, lipids, and carbohydrates). This allows them to grow and survive in an efficient manner. Nucleic acids account for their genetic material, proteins account for their build and physical makeup, lipids allow for flexible cell membranes and well as efficient energy storage, and carbohydrates provides the cells with the energy needed to do work. Dogs also have the ability to eliminate waste products, respond to external stimuli, and reproduce sexually. Unlike viruses, dogs are able to adapt to their environment. When introduced to a new environment, dogs tend change their behavior to increase their chances of survival. Essentially, viruses have unique traits which make them a virus. However, due to their lack of energy, inability to grow and reproduce independently, and inability to produce waste products and respond to stimuli, they cannot be considered a living thing.

Sara's Characteristics of a VIrus Arguementation

Should a Virus Be Considered a Living Thing?

Viruses should not be considered living things.  The reason why is because they have no energy source in order to perform their functions for survival.  According to the chart an Amoeba which, is considered a living thing has an energy source and it is organic compounds. However, the Influenza Virus has none under the category of energy source according to the chart  provided.  Also according to the chart the Adenovirus has no energy source as well.  What that means is that both viruses have no way of obtaining energy on their own in order to perform functions necessary for survival.  With no energy source means that they have no energy in order to do specific functions for survival on their own.  Since, energy can not be produced but only conserved and converted it means that the Influenza Virus and the Adenovirus can not perform functions for survival.  Both use the energy from a host in order to keep on dividing and infecting other cells but both can not survive on their own.  Therefore, with no way of being able to perform functions for survival viruses should be considered a non living thing.

Viruses should also not be considered living things because they do not respond to stimuli or grow on their own.  According to the chart Plasmodium Falciparum is a parasite that causes malaria and can respond to stimuli and grow on it's own.  Even though a virus is considered a parasite Plasmodium Falciparum is considered a protists.  Therefore, it is considered a living thing. However, both the Influenza Virus and the Adenovirus do not respond to stimuli or grow on their own.  By not responding to external stimuli that means they do not have the organelles required to respond to it. For instance, if the temperature changed drastically then both viruses would not respond to it by utilizing more energy in order to keep the organism warm. Also if another cell were to attack the viruses they would have no defense system to respond and fight back.  Both viruses do not show growth on their own according to the chart unlike other organisms like Tube Worms and Plasmodium Falciparum.  What that means is that the Influenza Virus and the Anedovirus have no process for cell division in order to occur on it's own. Since both require a host for replication according to the chart that means that growth is done with the help of  a host as well.  Since DNA replication is required for cell division to occur and cell division is how a cell can grow into many that means that a host provides the mechanisms required for the viruses' growth.  Therefore, if the viruses can not respond to external stimuli and can not grow on their own then they are not considered a living thing because in order for it to be living it has to be able to respond to its environment so it can adapt and also grow on its own so the genetic material can be passed down and stick around.

Joshua's Characteristics of Viruses Argumentation

Joshua Everett

Mr. Hammer

AP Biology

February 18, 2015 

Should a Virus be Classified as a Living Thing?

In order for something to be consider living, it has to meet the seven characteristics of life.  The seven characteristics of life include that they are composed of cells, they have different levels of organization, they use energy, they grow, they reproduce, they respond to respond to their environment, and they are able to adapt to their environment. For an organism to be considered a living thing, it has to have and be able to do all of these things and if something lacks even one of these characteristics it is considered nonliving. Based on these standards of living, viruses should not be classified as a living thing because they only meet the criteria for being able to reproduce and adapt to its environment. The characteristic for viruses to be able to reproduce is on the edge because they are only able to reproduce with the presence of a host cell. Viruses are only nonliving things that are composed of DNA or RNA that is enclosed by a protein shell that can infect cells by replicating their genetic material.

In contrast, some examples of organisms that  are classified as living things are sponges and elodeas. Sponges are living things because then obtain their energy from organic compounds which are commonly found inside food sources. They are able to respond to external stimuli such as their environment which is most common within oceans and rivers. Sponges are able to reproduce both sexually and asexually along with being able to grow and develop through cell division and enlargement. Elodea are also able to do the same things as sponges but instead of obtaining their energy from organic compounds, they obtain energy from sunlight. These organism obtain energy from their environment in order to maintain their order by forming complex from simpler molecules. The biological molecules found in sponges and elodea are nucleic acids, proteins, lipids, and carbohydrates. The cells within sponges and elodea have many organelles other structures that are able to respond to environmental conditions such as a drastic change in temperatures. This response in return allows them to be able to adapt to their environment despite their environmental changes. Both organisms reproduce either by sexual or asexual reproduction. Sexual reproduction is the joining of two sex cells and asexual reproduction is reproduction without the use of gametes. When reproduction occurs a copy of the DNA or RNA that is in these organisms are distributed among the cells. The sponge and elodea are also able to grow by dividing their cells and enlarging them through mitosis and the distribution of genetic material. Cells grow to a certain size and then divide which is the cause for an organism as a whole to be able to grow. Sponges and elodea are examples of classified living things because they have characteristics that meet the criteria for all living things.

Some examples of viruses include the influenza virus and adenovirus. Both viruses are unable to utilize energy sources to maintain order within them such as to perform biological processes. They are unable to respond to environmental changes which will cause them to potentially die because they are not able to protect themselves or adapt to the environment to stay alive. These viruses are unable to grow and develop which means their cells aren't dividing or enlarging which is customary within living things. Reproduction is also customary in living things and viruses are able to do this but only in the presence of host cells. If it wasn't for host cells, viruses would most likely be non existence which would make them nonliving.

Overall, viruses barely meet two of the seven criteria to be classified as a living thing. To be classified as a living thing, viruses would have to meet all seven of the characteristics of life and they barely meet two of them. Based on the comparison between what living things have and what viruses have, I conclude that viruses are not living things.

Nida Ali's Should A Virus Be Classified As A Living Thing?

Viruses should not be classified as a living thing. Viruses should be able to use their energy, grow/develop, reproduce, respond to their environment, have waste products and adapt to their environment. Unfortunately, not all viruses meet all of these characteristics. Based off of the data found in Information about Viruses and other objects found on Earth, several viruses such as the Influenza Virus and Adenovirus have no energy source, do not have any waste production, does not have a carbon source, does not respond to external stimuli and do not grow. In order for a virus to be considered “alive” it must reproduce, obtain/use energy, grow/develop and respond to the environment. Since viruses are not cells there is no need for food since no activity occurs. Viruses do not use their own energy nor do they produce energy. Also, viruses do not grow and conduct no activity inside of its protein coat. Since the Influenza Virus and the Adenovirus are not able to respond to stimuli, under certain conditions like being presented to sunlight, they would not be able to grow in comparison to Amoeba, which is a single celled animal, is able to grow since it is able to respond to external stimuli. The Influenza Virus and the Adenovirus do not have an energy source, which thus results in no growth. However, the Coriander seeds has an energy source and carbon source which thus results in growth. Due to these lacking characteristics, viruses reply on host cells to carry out all of their functions.

The Influenza Virus and Adenovirus both require a host cell in order for reproduction to occur. The Plasmodium Falciparum parasite has a form of reproduction of sexual and asexual but reproduction can only occur inside of a host cell. Viruses cannot use their genetic material by themselves, in order to be effective, the virus needs to be present in a living cell. These viruses are not considered living since they are unable to reproduce. Viruses are unable to divide by binary fission. Viruses can not divide or reproduce by themselves without a host cell, as seen in the Influenza Virus, Adenovirus and the Plasmodium Falciparum parasite. However, while comparing viruses to other organisms such as dogs, coriander seeds, Amoeba, Sponges, E.Coli Elodea and Tube worms, these organisms are considered alive since they are able to reproduce either by sexually, asexually or even both. Since viruses are unable to reproduce without a host cell, they are not considered alive.  Viruses need a living cell in order to function and reproduce. Viruses are not living when they remain outside of the cell. The virus contains genetic material and when it is outside of a living cell, it does not carry out its functions. Once the virus is inside the cytoplasm of a living cell, the virus can activate. The virus' DNA takes control of the cell once it's within the cytoplasm. To add, viruses do not move themselves even though they do react to some changes in their environment.

Moreover, since viruses lack characteristics such as being unable to grow/develop , lack energy, unable to reproduce, inability to produce waste products, and are unable to respond to external stimuli, then viruses should not be considered a living thing. Viruses rely on host cells to be productive and efficient. Viruses are unable to perform/ function without being present in a living cell, as seen with the Influenza Virus and Adenovirus.