Question

Which processes lead to most genetic variation in sexually reproducing organisms? Select all that apply. Select all that apply. random fertilization independent orientation of chromosomes in meiosis cytokinesis crossing over?

Answer 1

The tree processes that increase the genetic variation in sexually reproducing organisms are : random fertilization, the independent orientation of chromosomes in meiosis and the crossing over.

When using the term random fertilization biologists mean that there is no preference in choosing a reproductive mate, and that all of the individuals have the same chance to reproduce. This increases the genetic variability because it allows individuals with genetic differences to reproduce and leave offspring with their combined genetic traits.

The independent orientation of chromosomes in meiosis and the process of meiosis in general enable the existence of genetic differences between two generations ( parents and offspring generation). Due to meiosis the offspring is not an identical clone of the parent.

The crossing over is maybe the important process for increasing the genetic variation in sexual reproduction. During the process of meiosis two chromosomes in a chromosome pair that have the same genes (but sometimes different alleles of the same gene) can exchange parts of their DNA sequence. This process, called the crossing-over results in genetic differences in the chromosomes that are later passed to the offspring. In other words, the chromosomes inherited are ''mixed'' or changed a little bit, therefore different than the ''original'' ones that the parents had.

Answer 2

Crossing over, independent orientations (assortment) of chromosomes, random fertilization contribute the process of genetic variation. Crossing over leads to exchange of genetic information in between the sister chromatids.
The process of independent assortment, during metaphase 1, is responsible for the unique arrangement of the chromosomes, and have 2n possibilities.
Random fertilization is the cause of the selection of a particular sperm that fuses with the egg and leads to the formation of the embryo, and a typical genetic characteristic is shared between the two.