NEET BIOLOGY

Detailed explanation-1: -In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.

Detailed explanation-2: -Histone proteins are tightly coiled up inside the DNA as chromatin fibers, which further compact to create chromosomes. Condensed DNA is found in a tightly packed area of chromatin called heterochromatin.

Detailed explanation-3: -Figure 1: Chromosomes are composed of DNA tightly-wound around histones. Chromosomal DNA is packaged inside microscopic nuclei with the help of histones. These are positively-charged proteins that strongly adhere to negatively-charged DNA and form complexes called nucleosomes.

Detailed explanation-4: -DNA can be highly compacted Yet during mitosis and meiosis, this DNA molecule is compacted into a chromosome approximately 5µm long. Although this compaction makes it easier to transport DNA within a dividing cell, it also makes DNA less accessible for other cellular functions such as DNA synthesis and transcription.

Detailed explanation-5: -Condensing DNA into chromosomes prevents DNA tangling and damage during cell division.