NEET BIOLOGY

Detailed explanation-1: -Each chromosome consists of a single, enormously long linear DNA molecule associated with proteins that fold and pack the fine DNA thread into a more compact structure. The complex of DNA and protein is called chromatin (from the Greek chroma, “color, ” because of its staining properties).

Detailed explanation-2: -Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA).

Detailed explanation-3: -Chromosomes Are Most Compacted During Metaphase When eukaryotic cells divide, genomic DNA must be equally partitioned into both daughter cells. To accomplish this, the DNA becomes highly compacted into the classic metaphase chromosomes that can be seen with a light microscope.

Detailed explanation-4: -This is accomplished by wrapping the DNA around structural histone proteins, which act as scaffolding for the DNA to be coiled around. The entire structure is called a nucleosome, each of which includes an octamer of histone proteins and 146 to 147 base pairs of DNA.

Detailed explanation-5: -As shown in the animation, a DNA molecule wraps around histone proteins to form tight loops called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin. Chromatin, in turn, loops and folds with the help of additional proteins to form chromosomes.