لخّصلي

consider a population of insects in which females reproduce only once a year and then the adult population dies.In this case of discrete breeding, R = net reproductive rate, Net reproductive rate is used because it is the observed rate of natural increase after deaths have occurred, this graph shows how the population would grow year after year for 10 years, assuming that R stayed constant from generation to generation.With exponential growth, the number of individuals added each generation increases rapidly due to the total number of reproductive females increasing in the population.This growth curve, which is roughly J shaped, depicts exponential growth.Exponential growth phase: During this phase, growth is accelerating.

consider a population of insects in which females reproduce only once a year and then the adult population dies. Each female produces on the average 4.8 eggs per generation, half of which will develop into female offspring, which
reproduce the following year. In the next generation, the females
produce an average of 4.8 eggs. In this case of discrete breeding,
R = net reproductive rate, Net reproductive rate is used because it is
the observed rate of natural increase after deaths have occurred, this graph shows how the population would grow year after
year for 10 years, assuming that R stayed constant from generation to generation. This growth is equal to the size of the population, because all members of the previous generation have died, Mayflies, featured in Figure 44.7, have one reproductive event, which occurs in the spring. The development of the next generation requires as many as 50 molts during the winter. Figure 44.7b shows the growth curve for such a population. This growth curve, which is roughly J shaped, depicts exponential growth. With exponential growth, the number of individuals added each generation increases rapidly due to the total number of reproductive females increasing in the population. Notice that the growth curve in Figure 44.7b has two phases:
Lag phase: During this phase, growth is slow, because the population is small.
Exponential growth phase: During this phase, growth is accelerating.