Final answer:
The statement is true; the proportion of individuals across different age, size, and life history classes has a significant impact on how a population grows or declines, affecting factors like birth rates and life expectancy.
Step-by-step explanation:
The proportion of individuals in different age, size, and life history class will influence population growth. a) True b) False. This statement is indeed true. The demographics of a population, such as the distribution of individuals across various age classes, can greatly affect the population's growth. Younger individuals are more likely to reproduce, whereas older individuals have higher mortality rates. Additionally, the number of births compared to the number of deaths, or birth rate, will determine if a population is increasing, stable, or declining. Life expectancy also plays a role by affecting how long individuals contribute to the population's reproduction and resource consumption. These demographics are often represented within a life table. Population ecologists understand the significance of these factors and their impacts on predicting future changes within populations, leading to revisions and improvements of mathematical models used in population dynamics. To analyze population changes thoroughly, it's also important to consider the age-sex structure of a population, as these characteristics are critical in shaping the population growth.