DNA or Deoxyribonucleic Acid is what makes codes for our bodies and helps to determine what kind of make up each person, animal, plant or other living organism will have.

The DNA is the code for the creation of proteins and our DNA is the makeup of who we are.


When a living organism reproduces, it means that the organism makes another organism of the same kind. Most people, plants and animals use sexual reproduction in order to reproduce.

With sexual reproduction, there is an egg cell and a sperm cell.

Sexual reproduction requires these two organisms, the sperm and the egg. When the sperm joins with the egg cell, a zygote, or a new life form, happens.

Asexual Reproduction

Another type of reproduction is called asexual. Asexual reproduction is when organisms are formed from just one parent and then the organism that is formed is identical to its parent.

Asexual reproduction is mostly seen by invertebrate animals.When sexual reproduction happens, meiosis happens. Meiosis is when offspring have genes from each parent.

Haploid and Diploid

Haploid is when a cell has one of each type of chromosome and diploid is when a cell has chromosomes that come in pairs.

A sperm has 23 chromosomes, so this is called a haploid.

An egg has 23 chromosomes, so this is called a haploid.

A person has 46 chromosomes, and this is called a diploid.

When sex cells make the wrong number of chromosomes, the organism will not grow correctly or normally and this is called a meiosis error. One example of this is a child that is born with Downs Syndrome.


DNA or deoxyribonucleic acid helps to make chromosomes. The DNA looks like a twisted ladder or a double-helix and it is a code that helps to produce proteins.

The DNA is made up of repeating nucleotides. A nucleotide is made up of sugar group, a phosphate group and a nitrogen base.

There are four nitrogen bases called Guanine, Cytosine, Thymine and Adenine and these are the “steps” of the DNA ladder.

When DNA pair, there is always a system. For example, Adenine always combines with Thymine and Guanine always combines with Cytosine.

When this happens, DNA will replicate, or repeat itself. When DNA repeats itself, mitosis and meiosis can happen. DNA separates itself and then two ne strands of DNA form.


When a gene forms, it is a section of DNA that is located on a chromosome. The gene makes a specific protein and if there is any change to the gene or chromosome, a mutation happens. A mutation means a change.


When change or mutation happens, the DNA copies wrong and all of the proteins will be wrong as well.

When mutations happen, a cell changes and makes incorrect protein and this will change the way a person looks.

There are three types of mutations: substitution, addition and deletion.

Substitution mutation happens with a base pair is substituted for a different pair.

Addition mutation happens when a base pair is added to the DNA strand.

Deletion is when a base pair is subtracted from the DNA strand.

Facts About DNA

  • When a DNA mutates, it can cause the organism to have a hard time surviving.
  • Mutations that happen in the body cells cannot pass to offspring.
  • Mutations that happen in the sex cells pass to the offspring.
  • The four letters of the DNA alphabet are given for the four nitrogen bases: Adenine, Thymine, Guanine and Cytosine and they are A, T, G, and C.
  • The shape of the DNA is oftentimes called a Double-Helix.
  • The function of the gene is to help control the production of proteins.

What Did You Learn?

  • What does DNA stand for? DNA stands for Deoxyribonucleic Acid.
  • What is the shape of the DNA sometimes called? The DNA is sometimes called a Double-Helix because of its shape.
  • What happens when a base pair is subtracted from the DNA strand? Deletion happens when a base pair is subtracted from the DNA strand and this is a type of mutation.
  • Why is mutation dangerous? Mutation is dangerous because it can make it hard for the organism to survive.
  • What is a haploid? A haploid is when cells come in singles and not in pairs.