Question

Ribosomes are made up of
A. DNA and protein
B. DNA alone
C. RNA and proteins
D. RNA and DNA

Answer 1

Hint: The ribosome particles are found in large numbers within all the living cells where they serve as an important site for protein synthesis.

Complete Answer:
They occur as free particles in both the prokaryotic and eukaryotic cells and exist in the form of particles that attach themselves to the membranes of the cytoplasmic reticulum exhibited by all the eukaryotic cells.

Option A: DNA contains the genetic information of an organism, but ribosomes are not made up of DNA. But, they are made up of protein. Therefore, this is the incorrect option.

Option B: Ribosomes do not contain DNA, therefore, this is the incorrect option.

Option C: Ribosomes are composed of several protein subunits and ribonucleotides which are complexed together to form its final structure. The ribosomes present within the eukaryotic cells belong to 80S types while the prokaryotic ribosomes belong to 70S type. In comparison with rRNA, the protein content of the 80S ribosome is higher than that for the 70S ribosome type. Therefore, this is the correct option.

Option D: Ribosomes contain RNA but it does not contain DNA. Therefore, this is the incorrect option.

Thus, the correct option is C) RNA and proteins.

Note: The function of ribosomes is as follows,
- They are involved in synthesis of proteins.
- It helps in assembling amino acids to form proteins which are necessary to carry out cellular functions.