This is an alternate universe with two main genders and three sub-genders.

The main genders are:

1.      Male

2.      Female

The three sub-genders are:

1.      Alpha

2.      Beta

3.      Omega

The sub-gender test is taken at the age of 12, affecting every aspect of their lives, especially their occupation.

Alpha: They are about 10%-15% of the population. They are called ‘born leaders’ and have a high aptitude [HG1] in every field. They are mostly found in a high position in any job field and rarely Alphas are found working in a lower position. Due to their natural biological process, they are attracted to Omegas due to an Omega’s pheromones (which they can pick up through smell) increasing their libido to ten folds causing them to lose control and are unable to keep a rational mind during an Omega’s heat cycle. Alphas can mark an Omega through a bite on their nape forming a bond with them. Alphas can become immune to Omegas pheromones up to a certain extent with special medicines, but they usually prefer not to.

Beta: They make 80%-85% of the population and are called the general population. The talents they possess can vary greatly and the careers they pursue are varied too. Unlike Alphas and Omegas, they do not bond or emit pheromones. Though they are affected by an Omega’s pheromones, it does not affect their libido as much as it affects an Alpha and they do not lose their mind and can control themselves.

Omega: They form only 1%-5% of the entire population. They are what people derogatively call “Breeder” as they are born with a high fertility rate. Omegas can have very high aptitudes as well like Alphas or Betas, but they are looked down on and have a hard time finding a stable job due to their “Heat” process. It is their natural biological process that lasts for 3-5 days and releases very strong pheromones, that can attract any nearby Alpha or Beta. This can be suppressed or kept in check through a medicine called “Heat Suppressants”. The dosage differs from Omega to Omega and higher the dosage, the more expensive the suppressants are. The only value that society sees in them is their capability to give birth to Alphas. Hence, many rich and powerful Alphas, who do not have any child or do not have an Alpha heir, keep Omegas as their mistresses to produce an Alpha heir. 
Once an Omega is bonded (bitten in the nape by an Alpha), their heat would only affect their bonded Alphas unless the Alpha chooses to break the bonding.

Disclaimer:
 It is an Alternate universe and none of the societal prejudice depicted is real. Society is shown to be very prejudiced and merciless towards a particular sub gender. Hence, it is to warn the readers who are uncomfortable with such situations and strong prejudices. Please proceed with caution.