Crossing over is one of the most important events in meiosis because?
it produces new combinations of alleles on chromosomes. homologous chromosomes must be separated into different daughter cells. the number of chromosomes allotted to each daughter cell must be halved. homologous chromatids must be separated into different daughter cells. all of these reasons are true.

Meiosis is the process of cell duplication into haploid gametes or sex cells. Crossing over is one of the most important events in meiosis because it creates genetic variation in the offspring produced by organisms giving variety in the gametes of both parents. This process is what makes sexual reproduction differ from asexual reproduction.

answer: - b cells

explanation: -

there are many types of white blood cells present in our body. one such class of white blood cells are the lymphocytes. the b cells belong to the lymphocyte class of wbcs. the b cells perform their action against the pathogen by producing specialised proteins called as antibodies. these antibodies are produced as and when the b cells encounter pathogens in response to the antigens present on the surface of the pathogen. these antibodies bind to the antigens present on the pathogen and then, target them for destruction by other cells of the immune system.

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.

They must use the scientific method