NEET BIOLOGY

Detailed explanation-1: -During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses. The chromatin coils and becomes increasingly compact, resulting in the formation of visible chromosomes.

Detailed explanation-2: -The main events of prophase are: the condensation of chromosomes, the movement of the centrosomes, the formation of the mitotic spindle, and the beginning of nucleoli break down.

Detailed explanation-3: -During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis. The paired chromosomes are called bivalents, and the formation of chiasmata caused by genetic recombination becomes apparent. Chromosomal condensation allows these to be viewed in the microscope.

Detailed explanation-4: -In the first phase-prophase-a centriole, located outside the nucleus, divides. The long, threadlike material of the nucleus coils up into visible chromosomes, and the nuclear membrane disappears. From the centrioles, long, thin strands extend in all directions.

Detailed explanation-5: -In prophase, each chromosome becomes condensed and more visible, and there is the breakdown of the nuclear membrane and appearance of spindle fibers.