Which is a biotic factor?

rotting carcass

Which is biotic?

Leaf

A rock is classified as

nonliving and abiotic.

Why is a shell considered to be biotic?

because it came from something living

The Phoenix area of the Southwestern desert typically receives 8 inches of precipitation yearly, in two seasonal patterns. Even though it is an arid region, it has high biological diversity. Thin-leaf trees abound, such as palo verde and desert ironwoods. Wide varieties of cactus thrive, including the cholla, prickly pear, and saguaro. Wildlife includes insects, reptiles, many bird species, small rodents, and other mammals. Which factor in the Southwestern desert ecosystem is abiotic?

a rainstorm

Which describes the habitat of a frog?

marshes and ponds

Which best describes a bird’s role as it eats seeds

Niche

Which principle states that two species in the same habitat cannot have the same niche?

competitive exclusion principle

Which describes a grizzly bear’s habitat?

the physical area where the bear lives

What is an organism’s niche?

the role that an organism plays in the environment

the role that an organism plays in the environment

predator-prey relationship

Interactions between organisms and their environment impact the organism’s overall population. Zebra mussels are not native North America; they were brought here by ships travelling from Europe. They reproduce quickly and filter out plankton from the water reducing food for native fish. Native fish populations have started to decline. Which concept shows the relationship between zebra mussels and native fish?

competitive exclusion principle

Many organisms depend on the land as a food source. Seasons can affect the amount of food that is available to these organisms. How would a long, cold winter most likely affect a population of deer?

The deer population will decrease.

Hunter is studying for his ecology test. Which fact would least likely show up in his notes?

Populations have no effect on their environment.

Elephants shape their environment in many ways. They can change a forest to a grassy field or dig a hole that might become a pond. They clear large amounts of vegetation, which removes habitats for some organisms but makes the area inviting for other organisms. Which best describes possible interactions of elephants with the surrounding ecosystem?

both positive and negative

A biologist counts the number of rabbits in a population each year and observes a decrease in population. Since the coyote population has exploded, the biologist concludes that the coyote population has had a negative impact on the rabbit population. Which describes the biologist’s actions?

Inference