Synthesis chemicals from products of herbivores' metabolisms.
Organism that feeds on another individual.
Organism that the parasite feeds on.
An example of mimicry that is important in anti-predator defenses is when...
A harmless species resembles a dangerous species.
One difference between predators and parasites is that parasites...
Usually do not cause the immediate death of the organism they feed on.
Magpies and crows are scavenger birds that feed on the same food sources and cannot live in the same community. This is an example of...
A change in anatomy that results when two species compete for the same resource is called...
A symbiotic relationship in which one species benefits and the other is not affected is called...
How are secondary compounds useful to plants?
They are defense mechanisms and prevents them from being eaten.
How are secondary compounds useful to humans?
Some secondary compounds can be used for medicinal reasons.
How do ectoparasites differ from endoparasites?
Ectoparasites live externally and endoparasites live internally.
Explain how Darwin's finches illustrate the principle of character displacement.
Because the islands were isolated from each other, the species of birds on each island started to differ accordingly.
A biologist finds that when two species of paramecia are grown together in the laboratory, one species always outcompetes and eliminates the other. Inn ponds and other natural environments, however, the two species coexist. Suggest a hypothesis to explain this phenomenon.
When two organisms are alone together, they will compete. One organisms will outcompete the other, and will continue to eliminate the other, as opposed to when there are other organisms, it is harder for one organism to outcompete another.
Example of endoparasite.
Example of physical defense.
Example of mimicry.
Example of secondary compound.
Example of ectoparasite.
Example of a pollinator.
Number of species a community contains.
Relates the number of species in the community to the relative abundance of each species.
Relationship that explains how larger areas usually contain more species than smaller areas.
Indicates a community's resistance to change.
Why are there more species in the tropics than three re in the temperate zones?
Temperate habitats are younger, the climate is more stable in the tropics, and because plants can photosynthesize year-ruond, there is more energy averrable to support more organisms.
Why does species richness increase with increasing area?
Larger areas usually contain a greater diversity of habitats and thus can support more species.
What is the relationship between stability and species richness?
Communities with more species would contain more links between species. Also, species richness improves a community's stability.
Development of a community in an area that has not supported life previously.
Sequential replacement of species that follows disruption of an existing community.
Small, fast-growing, and fast-reproducing species well suited for invading and occupying a disrupted habitat.
A stable end point reached by a predictable series of stages.
The gradual, sequential development of species in an area.
Primary succession may occur...
On an island formed by a volcanic eruption.
A species that predominate early in the development of a community are called...
In the eastern United States, succession often begins with...
Weeds and grasses.
The stable end point of succession is called...
Why does primary succession often proceed very slowly?
There are no previous necessary minerals.
Describe two ways that bare rock can be converted into soil.
Freezing and thawing rock, and lichens colonizing the bare rock.
Name five events that could initiate secondary succession.
Name three factors that could influence the path of succession in a particular area.
The species present, the order they arrive, and the climate.
What are the characteristics of a pioneer species?
Small, fast-growing, fast-reproducing, well suited for invading and occupying a disturbed habitat.
A volcanic eruption removes all plant life from a valley below the volcano. Explain why succession following the eruption is likely to occur more quickly on the valley floor than on the steep slopes that form the valley walls.
The rain washes nutrients down the valley walls to the valley floor.
Order of succession that follows a forest fire.
Burned wood, ashes; Grasses, weeds; Shrubs; and Pines, spruces.
Very large terrestrial ecosystems that contain a number of smaller but related ecosystems within them.
Cold, treeless biome that forms a continuous belt across NA, Europe, and Asia.
Forested biome covered with cone-bearing evergreen trees.
Tropical or subtropical grasslands with scattered trees and shrubs.
Continuous layer formed by a treetop.
The biome that is characterized by the presence of permafrost is called...
Plants living in the taiga are adapted for...
Long, cold winters.
Prairie, steppe, and veldt are different names for the biome known as...
What is NOT an adaption that limits water loss in desert plants?
Broad, thin leaves.
The amount of light that reaches the floor of a tropical rain forest is limited by the...
Name two factors that limit tree growth in the tundra.
Temperature and permafrost.
What characteristic of grasses enables these plants to survive occasional fires and continuous grazing by animals?
They grow at or below the ground instead of at the tip.
How are the plants of savannas adapted to the rainfall patterns of this biome?
Trees shed their leaves and grass die and regenerate according to the season.
Describe three adaptations of desert organisms that conserve water.
Have waxy layers that reduce evaporation, open their stomata at night, and have spikes to defend from tother animals.
Why aren't the forests of the taiga cut down and converted into farmland as often as temperate deciduous forests?
They have poor growing season.
Why are vines so common in rain forests?
They climb to get light.
Describe the tropical rainforest.
High temperature, high precipitation, and low soil/nutrient content.
Describe the tundra.
Low temperature, low precipitation, and low soil/nutrient content.
Describe the temperate grasslands.
Medium temperature, medium precipitation, and high soil/nutrient content.
Describe the desert.
High temperature, low precipitation, and low soil/nutrient content.
Part of the ocean that receives sunlight.
Part of the ocean where sunlight can't penetrate.
Rich in organic matter and vegetation.
Contains little organic matter.
What is NOT an environmental factor that organisms in the intertidal zone must cope with?
Coral reefs form in the...
There are fewer species in the oceanic zone than in the neritic zone because the oceanic zone...
Has low nutrient levels.
A salt marsh is an example of an...
Are rich in vegetation.
What are some adaptations of intertidal organisms that enable them to survive in this zone?
Burrowing into the sand/mud, retreating into their shells, and clinging to surfaces.
Why is plankton important of aquatic ecosystems?
Because it is consumed by many larger organisms.
Explain how producers near deep-sea vents obtain energy.
Water that drains from agricultural fields during heavy rains or over-irrigation may contain high levels of nitrogen, phosphorus, and other nutrients. What effect might this water have if it is allowed to enter an oligotrophic lake?
It can cause an increase in vegetation/organic matter. In the long term, they would die, decompose, and have a negative effect on the lake because there would be less oxygen.
Density dependent factor
Factors that kill more individuals in large populations than in small ones.
Factors that kill the same percentage of a population regardless of its size.
Measures how crowded a population is.
Spatial distribution of individuals within the population.
A population increases rapidly after only a few generations; the larger the population gets, the faster it grows.
When a population size is at its carrying capacity, the birth rate equals the death rate and growth stops.
The number of individual the environment can support over a long period of time.
These countries are poorer than the more developed countries, and their populations are growing much faster. The rate is 0.02 per capita.
People in these countries are better educated, healthier, and live longer than the rest of the world's population. The rate is less than 0.01 per capita.
A clumped distribution...
May occur when resources are concentrated.
Is the average life span.
Is the change in the number of individuals in a population over a period of time.
In the exponential model, the growth rate...
Changes with population size.
According to the exponential model...
Population growth continues indefinitely.
What is NOT true of the carrying capacity in the logistic model?
The carrying capacity in the logistic model is the population size at which the birth rate equals the death rate.
What is NOT a density-independent factor for a population of deer in a forest?
The number of cougars in the forest.
Inbreeding can be harmful to a population because it...
Can increase mortality rate of offspring.
During the hunter-gatherer period of human history...
Death rates were high.
The cause of the decline in death rates following WW2 was...
Improved hygiene and medical care.
A scientist observes that the population of turtles in a pond shows a clumped distribution. Explain two reasons why turtles might show this kind of distribution.
1. Turtles need to get out of the water and into the sun, and the uneven distribution of logs causes clumped distribution. 2. Because of an uneven distribution of the turtles' food.
What is a survivorship curve? What are the three types of survivorship curves? Name an organism that shows each kind of curve.
Curve where the mortality rate data of different species tend to conform to one of three curves on a graph. Three types are as followed: Type I: Pattern where the likelihood of dying is small until late in life (humans). Type 2: Pattern where the probability of dying does not change throughout life (birds). Type 3: Pattern where organisms are very likely to die young, however if it survives this period, it has a good chance of surviving to old age (salmon).
Explain one key assumption of the exponential model of population growth. What does the model help scientists predict about changes in population size over time?
One key assumption is that the birth and death rates are constant. This predicts that population will increase indefinitely.
Explain three reasons why small populations are particularly vulnerable to extinction.
Because they are more vulnerable to disease, disasters, and have a low rate of population growth, and
What was the agricultural revolution? What effect did it have on population growth? Before the agricultural revolution occurred, how did people obtain food?
The dramatic change in lifestyle when humans discovered how to domesticate animals and cultivate certain plants for food. It caused the population to grow faster and increase population incredibly. They used to get food by being hunter-gatherers.
The human population began to grow very rapidly about 1650. Describe three factors that caused this change in the rate of population growth.
Improvements in hygiene, diet, and economic conditions.
Because we humans have more power to alter our environment than other animals do, we can affect the carrying capacity of our environment. How do we increase or decrease the carrying capacity of our local area?
Medicine and sanitation can increase carrying capacity.
The cause of the population cycle of the snowshoe hare is still a mystery. Suggest two possible explanations for why this cycle occurs. Describe how you would test each possibility.
The snowshoe hare are hunted by lynxes. As the population of lynxes rose, the population of hares decreased. Also, as the population of lynxes decreased, the population of hares increased. You can test this by observing these two populations in an area after many years.
Explain how disease could be a density-dependent factor in a population.
The more organisms, in a population, the faster the disease spreads, therefore killing more organisms.
Study of the interaction between organisms and the living and nonliving components of their environment.
Effect where CO2 and water vapor intercept reflects heat and directs it back to earth.
Thin layer of Earth and its atmosphere that supports life.
Smaller units of the biosphere that includes all of the organisms and nonliving environment in a place.
All interacting organisms living in an area.
All members of a species that live in one place.
What percentage of the world's species are expected to disappear in the next century if the current rate of extinction continues?
The ozone layer in the upper atmosphere is diminishing most over...
The broadest, most inclusive level of ecological organization is the...
A pond is an example of
Ecologists use models to
Account for the influence of every variable in a real environment.
What factors contributed to the extinction of native birds on the Hawaiian Islands after humans arrived?