Question

Explain chemotaxis and why it is helpful for fertilization.

Answer 1

Chemotaxis is the process of locomotion of a cell or an organism in response to a chemical substance. The chemical substance that can be organic or inorganic molecules facilitates the movement of cell or organism in a direction of increasing or decreasing concentration gradient, on the basis of this chemotaxis is of two type i.e. positive chemotaxis and negative chemotaxis.

Positive chemotaxis occurs in a direction that corresponds to a higher concentration of the chemical substance (chemoattractant) i.e. the movement toward the higher concentration of the chemoattractant.

Negative chemotaxis occurs in a direction that corresponds to a lower concentration of the chemical substance (chemorepellent) i.e. the movement towards the lower concentration of the chemorepellent.

Chemotaxis is helpful for fertilization as the sperms are attracted towards the oocyte that releases chemoattractant molecule, this chemoattractant molecule forms a concentration gradient around the oocyte in such a way that it’s higher concentration is towards the oocyte and its concentration lowers gradually as the distance from oocyte increases. The sperms follow this concentration gradient and move in a direction of the higher concentration of the chemoattractant molecule i.e. towards the oocyte.