Ecology

Front

Why are biologists removing pythons from the Everglades?

Back

The pythons could prey on native organisms and cause native populations to decline.

Front

Which of the following statements account for the change in population seen between years 7 and 8?

• The birth rate of the pigeons increased.
• The emigration rate of the pigeons decreased.
• The death rate of the pigeons exceeded the birth rate.
• The neighborhood reached its carrying capacity for the pigeon population.

Back

The death rate of the pigeons exceeded the birth rate.

Front

A new species of snake was introduced to a tropical region. Scientists then noticed a steady decline in the presence of field mice and an increase in the number of snakes. What is the most likely explanation for the change in population size of each animal?

Back

The mice became prey to the introduced snakes, allowing the snake population to increase but decreasing the mice population.

Front

What is the most important factor that influences the concentration of life in the top 200 meters of ocean water?

Back

amount of sunlight

Front

Rabbits introduced into Australia over 100 years ago have become a serious pest to farmers. Rabbit populations increased so much that they displaced many native species of plant eaters. What is the most logical explanation for their increased numbers?

Back

There are few effective predators.

Front

Scientists found, that over a period of 200 years, a mountain pond was transformed into a meadow. During that time, several communities of organisms were replaced by different communities. Which of these best explains why new communities were able to replace older communities?

Options:

The original species became extinct.

Species in the older community died from old age.

The abiotic characteristics of the habitat changed.

Diseases that killed the older organisms disappeared.

Back

The abiotic characteristics of the habitat changed.

Front

Why is phosphorus not very common in the biosphere?

Back

Phosphorus doesn’t cycle through food webs

Front

What does it mean when nitrogen is the limiting nutrient in the ocean?

Back

Nitrogen is scarce or cycles very slowly through the ecosystem.

Front

Level of organization: Group of individuals of the same species living in the same area.

Back

Population

Front

What is true about matter in the biosphere?

Back

Biogeochemical cycles transform and reuse molecules