To solve this problem, we need to identify which of the given options is not an attribute of a population. Let's analyze each option:$\newline \bullet$Natality:$\newline$ - Natality refers to the birth rate within a population. It is a measure of how many new individuals are added to a population through reproduction.$\newline$ - This is an attribute of a population.$\newline \bullet$Mortality:$\newline$ - Mortality refers to the death rate within a population. It measures the number of individuals that die in a population over a certain period.$\newline$ - This is an attribute of a population.$\newline \bullet$Species interaction:$\newline$ - Species interaction refers to the various ways different species interact with each other, such as predation, competition, and mutualism.$\newline$ - This is not an attribute of a single population but rather describes interactions between different species.$\newline \bullet$Sex ratio:$\newline$ - Sex ratio is the proportion of males to females in a population. It is an important demographic attribute of a population.$\newline$ - This is an attribute of a population.$\newline$Based on the analysis, the correct answer is Option 3: Species interaction, as it is not an attribute of a single population.