Question 8

There are four different types of nucleotides in DNA.

DNA is composed of four distinct types of nucleotides, which are the building blocks that form the genetic code. These nucleotides include adenine (A), thymine (T), cytosine (C), and guanine (G).

A) one

This option is incorrect because DNA is not made up of a single type of nucleotide. A single nucleotide cannot provide the diversity needed for genetic coding, which requires multiple types to create the sequences that encode information.

B) two

This option is also incorrect as it suggests that only two types of nucleotides exist in DNA. While there are pairs of nucleotides (A with T and C with G), the total number of unique nucleotide types is four, not two.

C) four

This option is correct because DNA consists of four unique nucleotides: adenine, thymine, cytosine, and guanine. Each of these nucleotides plays a crucial role in the structure and function of DNA, allowing for the complex coding of genetic information.

D) eight

This option is incorrect as it overestimates the number of nucleotide types in DNA. While DNA molecules may contain millions of nucleotides, there are only four distinct types that combine in various sequences to form the genetic material.

Conclusion

The correct answer is four, as DNA is made up of four different types of nucleotides essential for genetic encoding. All other options fail because they either underestimate or misrepresent the basic components of DNA, which are critical for understanding its structure and function.