Question

Ribosomes are made up of
a. DNA and protein
b. DNA
c. RNA and protein
d. RNA and DNA

Answer 1

The ribosome can be found freely in the cytoplasm. They are the protein synthesis units. It contains the larger and smaller subunits. The mRNA is attached to the smaller subunit which helps in coding while the larger subunit attaches to the polypeptide chain.

Complete answer:
A ribosome is the cell organelle present in the cell. It is made up of RNA and proteins, and each ribosome consists of two separate RNA- protein complexes. These two subunits are known as small and large subunits. The eukaryotic ribosomes are called as 80 S while the prokaryotic ribosomes are of 70S type. The 80S type of the protein content is higher while the 70S ribosomes contain less protein content.

The smaller subunit is attached to the mRNA which brings codons. The larger sub-unit is attached to the tRNA which brings amino acids and these subunits together form the polypeptide chain. The 30S has mainly decoding functions and 50S has mainly catalytic functions. The proteins stabilize the structure of the ribosomes.

The synthesis of the proteins occurs in four phases that are initiation, elongation, termination, and recycling. The process of synthesis of proteins from RNA is called translation. The AUG is the start codon. Three codons act as a stop codon UAA, UAG, or UGA, tRNA does not recognize these codons.

Many ribosomal units are attached to these units. Ribosomes are also called a ribonucleoprotein complex. Ribosomes do not contain any DNA. DNA is present in the nucleus.

From the above information we have found that ribosomes are made up of RNA and protein.
Hence, the correct answer is option (C).

Note: Ribosomes are present within all living cells. The scientist Richard B. Roberts proposed the term ribosome. Ribosomes can be found freely or membrane- bound organelles. Ribosomes play a very important role in two extremely important biological processes called peptidyl transfer and peptidyl hydrolysis.