Question

Be able to interpret growth curves for organisms grown under ideal conditions as well as those grown in poor conditions.

Answer 1

1. Growth curve under ideal conditions: Exponential growth curve

This graph shows exponential growth, which only happens under ideal conditions with unlimited space, food and no predators . So the growth curve under ideal conditions is called an Exponential curve. It shows rapidly increasing population growth due to each generation producing more offspring. It is a J shaped curve

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2. Growth curve under poor growing conditions: Logistic growth curve

Logistic Growth Carrying capacity Time

When the number of individuals gets large enough, resources start to get used up, slowing the growth rate. Eventually, the growth rate will plateau, or level off, making an S-shaped curve. The population size at which it levels off, which represents the maximum population size a particular environment can support, is called the carrying capacity, or K. For animals, important resources include food, water, shelter, and nesting space. Limited quantities of these resources results in competition between members of the same population, or intraspecific competition (intra- = within; -specific = species).

Intraspecific competition for resources may not affect populations that are well below their carrying capacity—resources are plentiful and all individuals can obtain what they need. However, as population size increases, the competition intensifies. In addition, the accumulation of waste products can reduce an environment’s carrying capacity.