How does sexual reproduction affect gene frequency?

1 Answer
Oct 8, 2017

It allows transferring of good genes and makes bad genes less frequent


Imagine two individuals, each with a different genotype. Person 1 has genotype AAbb, person 2 has aaBB

  • Gene A is the gene that makes sure that the eye is clear (so you can see). Allele a is a broken version; the person can not see. Allele a is recessive.
  • Gene B is the gene that makes sure that you have 5 fingers on each hand. Allele b is broken, as it gives a person only 4 fingers (no thumb). Allele b is recessive.

If these individuals were to reproduce asexually, their offspring would always be blind (for person 1) and thumbless (for person 2)

If these two people were to have sexual reproduction, they would be producing gametes.

Gametes for person 1 are always Ab, gametes for person 2 are always aB. If these two gametes were combined, you would get a zygote with genotype AaBb. The person that would grow out of this zygote would both be able to see AND have a thumb.

You may want to see these related Socratic questions:
What is the difference between sexual and asexual reproduction?
How is genetic variation increased by fertilization?