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Tumor & Cancer – What is the Difference?

Tumor & Cancer – What is the Difference?

In this post we will clear our doubts regarding the term tumor and cancer. The general misconception what I have noticed is, when we hear the term tumor we think it is a cancer. But in fact tumor does not necessarily mean cancer.

Tumor aka neoplasm (neo = new and plasma = formation) is an abnormal mass of a tissue due to the abnormal growth. As a result, at that particular site lump appears which is called tumor. It is not necessary that all the tumors are cancerous. Let’s try and understand it.

Tumors are of two types:

1. Benign tumors:

Benign tumors are “non-progressive”. This means benign tumors limit their growth to a particular site wherever they are formed in the body. It is not going to spread form this site to any other site in the body. It cannot metastasize which means it cannot spread anywhere else in the body. Therefore, such benign tumors are noncancerous and they can be removed by surgery.

2. Malignant tumors:

Malignant tumors are cancerous because they have the ability to metastasize. They can spread from its primary site to any other part of the body.

Therefore, when a tumor is detected, it is very important to do biopsy to understand whether it is a benign tumor or malignant tumor.

Cancer is the term used to describe an uncontrolled growth of a cell. It is not necessary that all cancers are characterized by appearance of tumor. For example, blood cancer.

Cancer is a malignant condition. Based on what type of cancer or what stage it is detected, surgery, radiation therapy or chemotherapy is given.

Therefore, the term tumor and cancer cannot be used as synonyms.

I hope this post helped 🙂

To understand more in details, watch a video on this topic here.

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Genotype and Phenotype – What is the Difference?

Genotype and Phenotype – What is the Difference?

To understand this topic we must know what are genes and alleles. We have already discussed these in one of the previous blog.

In brief genes are stretches or small sequences of DNA that codes for a particular trait. Alleles are different variants of the same gene which means they might have little difference in their sequence.

Such as we have hair color gene but all of us don’t have same hair color and that is because we carry different allele of the hair color gene.

Genotype:  In simple words it is what ‘we have’.

The complete genetic makeup of an individual or set of all the alleles that an individual possesses is called the genotype.  Set of genes or alleles in our DNA are responsible for a particular trait.

Let’s say for example eye color gene is coded by B and b where B is dominant; codes for brown color and b is recessive; codes for blue color. Since we are diploid we can have three different possible genotypes and that is homozygous dominant; BB or heterozygous; Bb or homozygous recessive; bb.

Genes are what are passed from one generation to another generation and that is why genotype is inherited.

So as we saw in above example we can have three possible genotypes and they would express something isn’t it? That expression or outcome of genotype is called phenotype.

Phenotype: In simple words it is what ‘we see’.

The physical appearance or expression of a particular trait or genotype is called phenotype. Most of the time it is the visible or observable expression of the genes. But phenotype also includes the biochemical properties because that also is a result of expression of particular genes.

Let’s take the eye color example again. Homozygous dominant BB genotype gives brown color phenotype. Heterozygous Bb gives brown color phenotype and homozygous recessive bb gives blue color phenotype.

Therefore, Genotype Determines the Phenotype.

If we put it in Punnett square as given below, it is easy to understand. We can have 3 different genotypes but they would express 2 different phenotypes.

I hope this post helps J

To understand more in detail, watch a video on this topic here.