Fact 1: Harming an animal species has a negative impact on the population size of that species.

Fact 2: Populations are the sub-units of species.

Given the two facts above, answer the question "harming an animal species has a negative impact on the what?" with the following options: 
- sub-units of species
 - single-celled organisms
 - diet of species
 - most organisms
 - color of species
 - ancestors of species
 - Abnormal cell growth
 - Males and females


 

 sub-units of species        