The correct answer is A. I:steroid; II:terpenoid; III:alkaloid; IV:DNA base.
Steroids are a class of lipids that are derived from cholesterol. They are found in all animal cells and are essential for many biological processes, including the production of hormones, bile acids, and vitamin D.
Terpenoids are a class of organic compounds that are derived from isoprene. They are found in plants, animals, and fungi, and they have a wide range of biological activities, including the production of essential oils, pigments, and vitamins.
Alkaloids are a class of nitrogen-containing organic compounds that are found in plants. They have a wide range of biological activities, including the production of drugs, toxins, and pigments.
DNA bases are the building blocks of DNA. They are adenine (A), guanine (G), cytosine (C), and thymine (T). DNA bases pair together in a specific way, with A always pairing with T and G always pairing with C. This pairing is essential for the replication and transcription of DNA.
Here is a more detailed explanation of each option:
- Option A: I:steroid; II:terpenoid; III:alkaloid; IV:DNA base. This is the correct answer. Steroids, terpenoids, and alkaloids are all organic compounds, while DNA bases are nitrogen-containing organic compounds. Steroids are derived from cholesterol, terpenoids are derived from isoprene, alkaloids are found in plants, and DNA bases are the building blocks of DNA.
- Option B: I:terpenoid; II:steroid; III:alkaloid; IV:DNA base. This option is incorrect because it has terpenoids and steroids switched. Terpenoids are derived from isoprene, while steroids are derived from cholesterol.
- Option C: I:terpenoid; II:steroid; III:DNA base; IV:alkaloid. This option is incorrect because it has alkaloids and DNA bases switched. Alkaloids are found in plants, while DNA bases are the building blocks of DNA.
- Option D: I:steroid; II:terpenoid; III:DNA base; IV:alkaloid. This option is incorrect because it has DNA bases and alkaloids switched. DNA bases are nitrogen-containing organic compounds, while alkaloids are found in plants.