Chromosomes along with DNA, Genes and other things help us to look like we look.

We all share some type of characteristics with our family members and because of your chromosomes, you have features such as dark hair, brown or blue eyes, dimples and more.


Heredity is when there are traits that are passed down from the parent to the offspring. Genetics is the study of heredity.


There are different cells in our body that have different genetic material.

The genetic material that is found in the nucleus of the cell is what gives us the physical characteristics that we have. This material is called DNA.

As we read before, DNA is also called Deoxyribonucleic Acid. The DNA is the instructions that are given to the organism on how to grow and what to look like.

Genetic material helps to make an individual have different characteristics that are also known as traits.


There are many traits that are inherited, and this means that the traits are similar to the parent traits.

Some of these include what color your hair will be, what color your eyes will be, your blood type and more.

Other traits are not inherited, and this means that they develop as you grow. Some traits are both inherited and acquired, and skin color is one of these.

Traits that are inherited happen through sexual reproduction.

When sexual reproduction happens, the cell that has the DNA material from the mother and the DNA material from the father come together to form a new cell and this is the offspring.


A chromosome is the structure that holds the DNA material. The chromosome is made up of the DNA that is tightly coiled together around the proteins.

Chromosomes are not able to be seen, even under a microscope, when the cell is not dividing, but when it is, the chromosome becomes in sight under a microscope because the DNA becomes packed tighter.

The chromosomes divide into sections and it helps to decide the location of a specific gene.

Chromosomes are thread like structures, and they are located in the nucleus of the living organism.

They are made up of proteins and of DNA and many of them are thought to be very colorful in the body.

What Do Chromosomes Do?

Chromosomes help to keep the DNA wrapped around the proteins. The DNA are very long and without the chromosomes, the DNA would be too long to fit inside of a cell.

If this happened, the organism would not be able to grow properly, and it could cause new cells not to reproduce.

The chromosomes are also important because they help the DNA to be copied correctly.

When mutation happens, it is part of the chromosomes fault because they might break or become lumped together.

If the chromosome changes, it can cause sicknesses to happen such as cancer.

If the chromosome copies the wrong amount of DNA, it causes offspring to develop improperly and can cause Down Syndrome.

What Do Chromosomes Look Like?

Chromosomes are different in all living things. Even though all living things have chromosomes, they are not the same.

Bacteria have chromosomes that are circular while chromosomes in humans and in animals are more linear shaped.


Centromeres are when chromosomes are linear. The centromere helps to make sure that the chromosome is in the right spot when cell division happens.

The centromeres help prepare the chromosome to be copied.


Telomeres help to protect the ends of the chromosomes. When a mutation occurs, the telomeres help to make the mutation stronger and so they play a role in causing cancer to develop.

How Many Chromosomes?

People have 23 pairs of chromosomes which means they have 46 total chromosomes.

Each plant or animal species has a specific number of chromosomes and each animal in that species has the same.

Male and Female

Females have two x chromosomes in their cells and males have one x and one y chromosome. This is what determines if a person is a boy or a girl.

Facts About Chromosomes:

  • The first chromosome was discovered in 1800 when scientists were looking under a microscope at cells.
  • Thomas Morgan helped to link chromosomes to inherited traits.
  • One copy of the chromosome is inherited from the mom and one copy of the chromosome is inherited from the dad.
  • A fruit fly only has four pairs of chromosomes.
  • A dog has 39 pairs of chromosomes.
  • Blood cells stop chromosomes from losing their telomeres.
  • The only part of the human cell that does not have a pair of chromosomes are the reproductive cells.

What Did You Learn?

  • What do chromosomes do? The chromosomes help to keep the DNA wrapped around the protein.
  • How many pairs of chromosomes do human beings have? Humans have 23 pairs of chromosomes.
  • Do boys and girls have a different set of chromosomes? Yes, boys have one x and one y chromosome and girls only have two x chromosomes.
  • Traits can be inherited or acquired. What does acquire mean? Acquired traits means that they happened through the environment, like getting thicker hair if you live in the cold regions.
  • Do all creatures have the same number of chromosomes? No, each species has their own special number of chromosomes.