plant movement:

-for a given body size which has higher population density birds or mammals?
Answer: birds have higher population density for a given body size because of birds high mobility population density increase through the supplyy of immigrants.

-on average, which lives at lower population densities, terrestrial or aquatic invertebrates.
Answers: Terrestrial species have lower population compared to aquatic invertebrates depending on their body size on their thermoregulatory system.

- diffentiate logistic growth geometric growth and exponential growth of population.
Answers: Geometric growth and exponential growth are the two basic models for estimating population growth.  The annual rate of population of a certain using these two models assumptions.  On the other hand in most real populations both food and disease become important as conditions become crowded.  There is an upper limit to the number of individuls the environment can support which ecologist refer to as the " carrying capacity " of the environment, population in this kind of environment is what is known as logistic growth.

- discuss the relationship exist in the population growth in relation to population size and density.
Answers: population growth rate depends on current population size, population slowly approaches carrying capacity when there is a delay, population growth depends on past population size, the population may have chaotic dynamics.  In many habitats, the forces that may limit population growth, like extreme weather events may decrease populations, which means population size is independent of population density.  Other factors like disease outbreaks and starvation are some factors that may increase with population density.