NEET BIOLOGY

Detailed explanation-1: -Recombination in meiosis. Recombination occurs when two molecules of DNA exchange pieces of their genetic material with each other. One of the most notable examples of recombination takes place during meiosis (specifically, during prophase I), when homologous chromosomes line up in pairs and swap segments of DNA.

Detailed explanation-2: -Answer and Explanation: In meiosis, an event called crossing over provides genetic recombination. When sister chromatids line up to separate into different parts of the cell to ultimately form two cells, they cross over. Crossing over is aided by proteins that lineup homologous parts of sister chromatids.

Detailed explanation-3: -Crossing-over results in genetic recombination by producing a new mixture of genetic material. Each homologous pair consists of four chromatids, because each chromosome in the pair had replicated before meiosis began. Homologous pairs (tetrads) are still paired together and arrange in the middle of the cell.

Detailed explanation-4: -During crossing over, part of one chromosome is exchanged with another. The result is a hybrid chromosome with a unique pattern of genetic material. Gametes gain the ability to be genetically different from their neighboring gametes after crossing over occurs.

Detailed explanation-5: -During meiosis, there is an important step to genetic variation. This step is called crossing over, or a crossover, and is unique to gametes. Crossing over occurs when chromosomes “trade” sections of their DNA, shuffling genes between them.