chromosomal crossover is the process that results in an exchange of genes between homologous.
chromosomal crossover is the process that results in an exchange of genes between homologous.
what process results in an exchange of genes between homologous?
chromosomal crossover
crossovers typically occur between homologous regions of matching chromosomes, but similarities in sequence and other factors can result in mismatched alignments. most dna is composed of base pair sequences repeated very large numbers of times. these repetitious segments, often referred to as satellites, are fairly homogenous among a species. during dna replication, each strand of dna is used as a template for the creation of new strands using a partially-conserved mechanism; proper functioning of this process results in two identical, paired chromosomes, often called sisters. sister chromatid crossover events are known to occur at a rate of several crossover events per cell per division in eukaryotes. most of these events involve an exchange of equal amounts of genetic information, but unequal exchanges may occur due to sequence mismatch. these are referred to by a variety of names, including non-homologous crossover, unequal crossover, and unbalanced recombination, and result in an insertion or deletion of genetic information into the chromosome. while rare compared to homologous crossover events, these mutations are drastic, affecting many loci at the same time. they are considered the main driver behind the generation of gene duplications and are a general source of mutation within the genome.
chromosomal crossover
chromosomes are linear arrangements of condensed deoxyribonucleic acid (dna) and histone proteins, which form a complex called chromatin. homologous chromosomes are made up of chromosome pairs of approximately the same length, centromere position, and staining pattern, for genes with the same corresponding loci. one homologous chromosome is inherited from the organism's mother; the other is inherited from the organism's father. after mitosis occurs within the daughter cells, they have the correct number of genes which are a mix of the two parents' genes. in diploid (2n) organisms, the genome is composed of one set of each homologous chromosome pair, as compared to tetraploid organisms which may have two sets of each homologous chromosome pair. the alleles on the homologous chromosomes may be different, resulting in different phenotypes of the same genes. this mixing of maternal and paternal traits is enhanced by crossing over during meiosis, wherein lengths of chromosomal arms and the dna they contain within a homologous chromosome pair are exchanged with one another.
homologous chromosome