MCQ
Q.
DNA are composed only of:
Correct Answer: A
Concept-
- DNA stands for Deoxyribonucleic acid.
- DNA as an acidic substance present in the nucleus was first identified by Friedrich Meischer in 1869.
- He named it ‘Nuclein’.
- DNA acts as the genetic material in most organisms.
- A DNA molecule consisting of all the genetic material of an organism is known as a chromosome.
- These are thread-like (helical) structures of protein and nucleic acids which carry all the genetic information in the form of genes.
Explanation-
- Deoxyribonucleic acid (DNA) is a nucleic acid and is therefore made up of nucleotide.
- Each nucleotide consists of a phosphate group, a nitrogenous base (A, T, G, C), and ribose sugar (deoxyribose in case of DNA).
- A nucleoside contains only pentose sugar and a nitrogenous base.
- Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two types of nucleic acids found in living systems.
- DNA is a long polymer of deoxyribonucleotides.
- The length of DNA is usually defined as the number of nucleotides (or a pair of nucleotides referred to as base pairs) present in it.
Thereby DNA is composed only of nucleic acid.
Additional Information
Lipids:
- These organic compounds are nonpolar molecules, which are soluble only in nonpolar solvents and insoluble in water because water is a polar molecule.
- In the human body, these molecules can be synthesized in the liver and are found in oil, butter, whole milk, cheese, fried foods, and also in some red meats.
Proteins:
- Proteins are composed of amino acids, arranged into different groups.
- These fundamental amino acid sequences are specific and their arrangements are controlled by the DNA.
- These are the fundamental building blocks of our bodies.
- They are large and complex macromolecules or bio-molecules which perform a major role in the functioning and regulating of our body cells, tissues, and other organs in the human body.
