Errors in DNA structure, also known as mutations, can have a big effect on how traits are passed down through families. To understand these errors, it helps to know what DNA is and how it works.
DNA is made up of smaller parts called nucleotides. Each nucleotide has three parts: a sugar, a phosphate group, and a nitrogenous base.
The DNA structure looks like a twisted ladder, known as a double helix. The “rungs” of this ladder are formed by pairs of bases: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). This pairing helps DNA copy itself during cell division, making sure that genetic information gets passed on correctly.
Point Mutations: This happens when just one nucleotide is changed, taken away, or added. For example, sickle cell anemia happens because of a point mutation in the hemoglobin gene. Here, adenine (A) is switched with thymine (T), which causes the body to make a faulty form of hemoglobin.
Insertions and Deletions: If one or more nucleotides are added or removed, it can create a frameshift mutation. This shift changes how the genetic code is read, which could affect all the amino acids that come after the mutation. It often leads to proteins that don’t work properly.
Copy Number Variations: Sometimes parts of DNA are repeated. This can create differences that change how genes are expressed. For example, people have different numbers of copies of the AMY1 gene, which helps digest starch. This variation can be linked to what people in different populations eat.
Mutations can change how traits are inherited in several ways:
Helpful Mutations: Some mutations are beneficial. For instance, certain bacteria develop resistance to antibiotics, helping them survive and evolve more quickly.
Harmful Mutations: Other mutations can cause genetic disorders. For example, cystic fibrosis happens because three nucleotides are deleted from the CFTR gene, which can lead to serious health problems.
Neutral Mutations: Many mutations don’t affect the organism at all. This is often because they occur in parts of the DNA that don’t code for proteins.
In short, mutations in DNA play an important role in genetic inheritance. They can create diversity in populations, which is important for evolution, but they can also cause inherited diseases. Because of this, keeping DNA healthy is vital for proper reproduction and survival.
Errors in DNA structure, also known as mutations, can have a big effect on how traits are passed down through families. To understand these errors, it helps to know what DNA is and how it works.
DNA is made up of smaller parts called nucleotides. Each nucleotide has three parts: a sugar, a phosphate group, and a nitrogenous base.
The DNA structure looks like a twisted ladder, known as a double helix. The “rungs” of this ladder are formed by pairs of bases: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). This pairing helps DNA copy itself during cell division, making sure that genetic information gets passed on correctly.
Point Mutations: This happens when just one nucleotide is changed, taken away, or added. For example, sickle cell anemia happens because of a point mutation in the hemoglobin gene. Here, adenine (A) is switched with thymine (T), which causes the body to make a faulty form of hemoglobin.
Insertions and Deletions: If one or more nucleotides are added or removed, it can create a frameshift mutation. This shift changes how the genetic code is read, which could affect all the amino acids that come after the mutation. It often leads to proteins that don’t work properly.
Copy Number Variations: Sometimes parts of DNA are repeated. This can create differences that change how genes are expressed. For example, people have different numbers of copies of the AMY1 gene, which helps digest starch. This variation can be linked to what people in different populations eat.
Mutations can change how traits are inherited in several ways:
Helpful Mutations: Some mutations are beneficial. For instance, certain bacteria develop resistance to antibiotics, helping them survive and evolve more quickly.
Harmful Mutations: Other mutations can cause genetic disorders. For example, cystic fibrosis happens because three nucleotides are deleted from the CFTR gene, which can lead to serious health problems.
Neutral Mutations: Many mutations don’t affect the organism at all. This is often because they occur in parts of the DNA that don’t code for proteins.
In short, mutations in DNA play an important role in genetic inheritance. They can create diversity in populations, which is important for evolution, but they can also cause inherited diseases. Because of this, keeping DNA healthy is vital for proper reproduction and survival.