Remora fish attach themselves to the bellies of sharks and travel everywhere the sharks go. Remora fish eat parasites present on the sharks, keeping the sharks clean and healthy. Why is this relationship an example of mutualism?

The table shows four examples of interactions between two organisms.

Which examples represent parasitic relationships?

The American cancer root is a non-photosynthetic plant that attaches itself to the roots of some oak tree species. The plant obtains nutrients from the roots of the oak tree, while limiting the amount of water the oak trees can absorb. Which ecological relationship does the American cancer root plant share with an oak tree?

The American alligator and the freshwater crocodile are similar species that feed on fish, amphibians, mammals, and birds. The alligator is found in America whereas the freshwater crocodile is found in Australia. Which statement describes the most likely interaction between these two species if they were suddenly living in the same ecosystem?

In an experiment, a scientist introduces 20 freshwater fish of the same kind into an aquarium containing freshwater. The next day, the scientist decreases the pH of the water by adding vinegar. The scientist continually decreases the pH every day by adding an additional 100 mL of vinegar. The graph shows the data collected. What effect does acidifying the water have on the population size?

Examine the diagram that shows a pond and several organisms that live in it. A flock of geese migrates to the pond. Which statement describes a possible negative effect of this migration on the pond environment?

The graph shows the population of honeybee colonies from 1935 to 2015. What is a reasonable explanation for the trend in the population of honeybee colonies?

Examine the graph. What is represented by the dashed line on the graph?

Caribbean reef squids have many color-changing cells called chromatophores just below the surface of their skin. These cells help them change their skin colors and patterns. The adult male Caribbean reef squids change their color from mottled green to bright red. They also show zebra-like patterns to exhibit good health and physical strength. These patterns and bright colors are very different than the seafloor where they live. The reef squids that are best able to change colors are the first to reproduce.

Which is the most likely reason for Caribbean reef squids to change their skin to different colors and patterns?

Which two examples show animals using a visual method for communication?

The image shows a male peacock spider lifting two of its legs and its colorful tail flap up in the air. Why does a male peacock spider display this kind of behavior?

Walnut sphinx caterpillars make a squeaking sound that resembles the alarm call made by birds. What is the most likely use of this sound to the caterpillar?

Why do animals communicate?

Over time, a rabbit population reaches its carrying capacity. Which factor would cause the carrying capacity to decrease?

Two organisms of different species exist in a relationship in which each individual benefits from the activity of the other:

Sloth's and monkeys share the same tropical habitat. Deforestation is occurring limiting the space for these 2 species. What will now occur between the 2 species?

In a forest ecosystem, deer and rabbits both feed on the same type of grass. What type of ecological relationship do they share?

Which factor would most likely lead to an increase in the carrying capacity of a wolf population in a forest?