What are the structures called that give an appearance as ‘beads on a string’ in the chromosomes when viewed under an electron microscope?
What are the structures called that give an appearance as ‘beads on a string’ in the chromosomes when viewed under an electron microscope?
The correct option is C Nucleosomes
Nucleosomes appear as ‘beads on string’ in the chromosome when viewed under an electron.
microscope. The beads in ‘beads on a string’ arrangement are complex of histones and DNA. The bead plus the connecting DNA that leads to the next bead form the nucleosome. The nucleosome is the fundamental unit of organization on which the higher order packaging of chromatin is built. The bead of each nucleosome contains eight histone molecules in which two copies each of H2A, H2B, H3 and H4 are found.
A gene is the basic unit of heredity and a sequence of nucleotides in DNA or RNA that encodes for the synthesis of a gene product, either RNA or protein.
A nucleotide is the monomer of a polynucleotide chain (DNA or RNA). It is made of three components: a nitrogenous base, a pentose sugar (ribose in case of RNA and deoxyribose for DNA), and a phosphate group. There are two types of nitrogenous bases – purines (adenine and guanine), and pyrimidines (cytosine, uracil and thymine).
A base pair consists of two nitrogenous bases linked by hydrogen bonds in a DNA double helix.
Nucleosomes appear as ‘beads on string’ in the chromosome when viewed under an electron.
microscope. The beads in ‘beads on a string’ arrangement are complex of histones and DNA. The bead plus the connecting DNA that leads to the next bead form the nucleosome. The nucleosome is the fundamental unit of organization on which the higher order packaging of chromatin is built. The bead of each nucleosome contains eight histone molecules in which two copies each of H2A, H2B, H3 and H4 are found.
A gene is the basic unit of heredity and a sequence of nucleotides in DNA or RNA that encodes for the synthesis of a gene product, either RNA or protein.
A nucleotide is the monomer of a polynucleotide chain (DNA or RNA). It is made of three components: a nitrogenous base, a pentose sugar (ribose in case of RNA and deoxyribose for DNA), and a phosphate group. There are two types of nitrogenous bases – purines (adenine and guanine), and pyrimidines (cytosine, uracil and thymine).
A base pair consists of two nitrogenous bases linked by hydrogen bonds in a DNA double helix.
