Chapter 50
Introduction to Ecology & the Biosphere
The Scope of Ecology
1. Define ecology. Identify the two features of organisms studied by
ecologists.
Ecology is the science that deals with the relationship of an organism to its
environment. Two features that are studied might be an organism's niche and its
habitat.
2 Distinguish between abiotic and biotic components of the environment.
Biotic Factors: relates to the biological parts of the environment features include:
· All the living organisms
· How many types there are
· Their numbers
· Distribution and
· Interactions
Abiotic Factors relates to the physical parts of the environment this includes chemical
factors like
· Temperature
· Rainfall
· Type of soil
· Salinity of water
3. Describe the problems caused by introduced species and illustrate with a
specific example.
Also known as exotic species, these are plants or animal life that is introduced from a
foreign ecosystem. This can cause biodiversity loss and other damage to local
ecosystems.
Introduced species are often dangerous to native species because they have not evolved
together and therefore compete for food and shelter.
Fire Ant
Insect South America; accidentally introduced to Alabama in 1930s
300 million acres of Southern U.S.,including most of eastern Texas
Aggressive, multiple biter with painful venom and chance of allergy; may also damage
fruits, berries and young crops; also damage electric boxes; antmounds are a hazard
to farm equipment
West NileVirus
Virus Uganda, Africa; firstappeared in TXin2002ThroughoutTexas
(213counties);spread through mosquitos Human health hazard; a total of 202 serious
cases and 13 deathsin humans as well as many affected horses and birds
Hydrilla Aquatic Plant Asia, Africa,Australia; introduced in the 1950s in the
aquarium trade Spread throughout SE U.S. and as far west as TX and CA High
reproductive potential thereby outcompeting native vegetation for resources
Chapter 52
Population Ecology
Characteristics of Populations
4 Explain how density-dependent factors affect population growth.
Density dependent factors typically involve biotic factors, such as the availability
of food, parasitism, predation, disease, and migration. As the population
increases, food become scarce, infectious diseases can spread easily, and many of
its members emigrate.
Chapter 53
Community Ecology
Interspecific Interactions and Community Structure
5. Explain how cryptic coloration and warning coloration may aid an animal in
avoiding predators.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/M/Mimicry.html
6. Distinguish between Batesian mimicry and MŸllerian mimicry.
Batesian mimicry is a form of mimicry typified by a situation where a harmless species
has evolved to imitate the warning signals of a harmful species directed at a common
predator.
7. Distinguish among parasitism, mutualism, and commensalism.
Chapter 54
Ecosystems
Ecosystems, Energy, and Matter
8. Describe the fundamental relationship between autotrophs and
heterotrophs in an ecosystem.
9. Name the main processes driving the water cycle.
10. Name the major reservoirs of carbon.