What is a stem cell?

A stem cell is a cell with the unique ability to develop into specialised cell types in the body. In the future, they may be used to replace cells and tissues that have been damaged or lost due to disease.

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What is a cell?

Cells are the basic building blocks of living things. The human body is composed of trillions of cells, all with their own specialised function. 

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Transport Across Membrane (with 3D animation)

The set of mechanisms that regulates the passage of substances like the ions and small molecules through the cell membrane or the plasma membrane, refers to as membrane transport. The plasma membrane being semipermeable in nature allows certain solutes to pass through while denies the passage for some others. Continue reading

Cell Cycle, Mitosis and Meiosis-3D Animation

The only way to make new cells is by duplicating the existing cells. During the process of cell division, the cell duplicates its content and then divides into two. This process of duplication and division is known as the cell cycle. Before the actual division takes place the cell goes through an inter-phase that consists of G1 (Gap 1), S (Synthesis) and G2 (Gap 2) phases. Continue reading

What is DNA Replication?

DNA replication is the process by which DNA makes a copy of itself during cell division.

  1. The first step in DNA replication is to ‘unzip’ the double-helix structure of the DNA
  2. This is carried out by an enzyme called helicase which breaks the hydrogen bonds holding the complementary bases of DNA together (A with T, C with G).
  3. The separation of the two single strands of DNA creates a ‘Y’ shape called a replication ‘fork’. The two separated strands will act as templates for making the new strands of DNA.
  4. One of the strands is oriented in the 3’ to 5’ direction (towards the replication fork), this is the leading strand. The other strand is oriented in the 5’ to 3’ direction (away from the replication fork), this is the lagging strand. As a result of their different orientations, the two strands are replicated differently:

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Do we really use only 10% of our brain?

Most of us believe in the fact that we use only 10% of our brain. In an average, an adult spends 20% of the total glucose burnt to sustain the brain’s energy requirement, while in children the value goes up to 50% and in infants, it is 60%. As a matter of fact the brain requires a lot of energy to function properly, why has the 90% of the supposedly used fragment of the brain didn’t vanish in due course of evolution? Why is it present till now? Watch the video below to get an answer to the question.

 

What is DNA?

DNA or deoxyribonucleic acid is a long molecule that contains our unique genetic code. Like a recipe book, it holds the instructions for making all the proteins in our bodies.  

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What is a genome?

A genome is an organism’s complete set of genetic instructions. Each genome contains all of the information needed to build that organism and allow it to grow and develop. 

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Branches of Biology and their Fathers​

Here is list of various fields of biology and scientists who are regarded as father or founder of each of the field.

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DNA Replication-3D Animation

Deoxyribonucleic acid (DNA), the genetic material for most of the living organisms, duplicates itself before the cell division by the process of cell division. This animation briefly explains the process of DNA replication, that involves enzymes like the Helicase, Primase, DNA polymerase, Exonuclease and DNA ligase. It also talks about the leading and the lagging strand present at the replication fork.

DNA to Protein- 3D Animation

The information stored in the DNA is decoded by the process of transcription and translation and results in the formation of the polypeptide chain or the protein, a very important and essential biomolecule in any living organism. This video provides a broad and clear picture of the process of gene expression with the help of the beautiful 3D model. You could also see the organization of the DNA, Histone protein, and the chromosome.

Electron Microscopic Images of HIV

Here are some of the images obtained via the electron microscope along with some of the relevant  information.

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Scanning electron microscopic (SEM) image of the human immunodeficiency virus (HIV-1), co-cultivated with human lymphocytes. (Photo Source: PHIL/CDC)

This scanning electron microscopic (SEM) image revealed the presence of the human immunodeficiency virus (HIV-1), which had been co-cultivated with human lymphocytes. Note the lymphocyte in the lower left, and some of its extended pseudopodia. HIV-1 virions can be seen on the surface of this lymphocyte.  Continue reading

HIV and its progression to AIDS

HIV

The human immunodeficiency virus (HIV) is one of the most unique and dangerous virus. I say unique because of the fact that once the virus colonizes the host, the host cannot get rid of the virus till it is alive. That means that once a person is having HIV, he/she has to live it with for the rest of his/her life. It basically compromises the human immune system, giving an easy access to various pathogens to the body, that is otherwise not possible in a normal condition. Continue reading