In this simulation you can observe the different levels of organization inside the body. Level by level, enter the body, then the cell and the nucleus, until you reach the chromosomes and DNA.
- To observe the different levels of organization, choose the magnification button and advance level by level.
- To return to previous stages, choose the reduction button .
Instructions:
Journey Into DNA
Journey into DNA
Each and every cell in our body contains DNA - the genetic material that carries the information that codes for all of the person's genetic traits. DNA (deoxyribonucleic acid) is a molecule that contains segments called genes. Each gene is a unit of information pertaining to a certain genetic trait and it dictates how that characteristic will be expressed in the body.
Where are the chromosomes? Where is the DNA?
Embark on a journey to DNA and discover the different levels of organization within the human body.
Into the Body
The journey to DNA begins within our body. Our body is made up of millions of cells, each of which contains genetic material (DNA).
Into the Lungs
Our body contains various organs, tissues, and cells. They all have different shapes and functions, but the genetic material in them all is identical.
For example, although lung cells cannot perform the functions of brain cells, they both contain identical DNA.
Into the Cell
Each and every cell in our body contains a nucleus, which is the "heart and core" of the cell. The nucleus is surrounded by a membrane that separates it from the rest of the cell. The nucleus contains the person's genome. A genome is the genetic information needed both to build the body and to make it function.
Into the Nucleus
The chromosomes are located in the nucleus. Each chromosome is part of the entire genome. Each species of every living creature has a typical number of chromosomes.
For example, each cell in the human body contains 23 pairs of chromosomes, for a total of 46 chromosomes.
Into the Chromosome
Each chromosome contains genes. Each gene determines a particular trait.
For example, a gene on chromosome X determines the way we see colors. When it is damaged, our color perception is affected (color blindness).
Into the Gene
Each chromosome is made up of one long, twisted, spirally, compacted DNA molecule. Different proteins support the DNA molecule so that it maintains its shape.
Each gene is a unit of information about a specific trait, and is located at a fixed position along the DNA molecule within the chromosome.
Into the DNA
If the DNA molecule is stretched out and all of its complex kinks and twists are smoothed out, an interesting structure is revealed: The two strands of the DNA have the shape of a twisted ladder, known as a double helix. These two strands are connected by transverse bonds.
If the DNA from all 46 chromosomes of one body cell is unfolded and set out end-to-end, its total length would be about 1 meter!
The Building Blocks of DNA
The DNA molecule is made up of four kinds of bases. They are joined to one another to form pairs and create the transverse bonds between the two strands of the double helix.
The four bases are:
A = Adenine
T = Thymine
C = Cytosine
G = Guanine
The composition of the base pairs is fixed. Adenine is connected to Thymine, and Guanine is connected to Cytosine.
