AP BIOLOGY

Detailed explanation-1: -Crossing over is the reciprocal exchange of segments between non-sister chromatids of a pair of homologous chromosomes. It results in recombination of genes or the linked alleles.

Detailed explanation-2: -During the alignment, the arms of the chromosomes can overlap and temporarily fuse, causing a crossover. Crossovers result in recombination and the exchange of genetic material between the maternal and paternal chromosomes. As a result, offspring can have different combinations of genes than their parents.

Detailed explanation-3: –Through crossing over segments of homologous chromosomes are interchanged and hence provide the origin of new characters and genetic variation.-Crossing over plays a really important role within breeding to enhance the varieties of plants and animals. So, the correct answer is ‘(d) Recombination of alleles.

Detailed explanation-4: -Crossing over is the exchange of genes between two chromosomes, resulting in non-identical chromatids that comprise the genetic material of gametes (sperm and eggs). This process results in the millions of sperm or eggs that are produced by an organism, each being different from one another.

Detailed explanation-5: -Crossing over is a cellular process that happens during meiosis when chromosomes of the same type are lined up. When two chromosomes-one from the mother and one from the father-line up, parts of the chromosome can be switched. The two chromosomes contain the same genes, but may have different forms of the genes.