Elephants Are Not the Most Dominant Species in African Grasslands

question 25

Multiple Choice

Elephants are not the most dominant species in African grasslands, yet they influence community structure. The grasslands contain scattered woody plants, but they are kept in check by the uprooting activities of the elephants. Take away the elephants, and the grasslands convert to forests or to shrublands. The newly growing forests support fewer species than the previous grasslands. Which of the following describes why elephants are the keystone species in this scenario?

• A) Elephants exhibit a disproportionate influence on the structure of the community relative to their abundance.
• B) Grazing animals depend upon the elephants to convert forests to grassland.
• C) Elephants prevent drought in African grasslands.
• D) Elephants are the biggest herbivore in this community.
• E) Elephants help other populations survive by keeping out many of the large African predators.

Describe the concepts of receptive fields and their importance in processing visual information.

Understand the process and pathways of visual information from the eye to the brain, including the role of the optic nerve and optic chiasm.

Explain the significance of binocular vision and how visual information is integrated from both eyes.

Identify the neurotransmitters involved in the autonomic nervous system and their effects on organ systems.

---

Definitions:

Discrete Random Variable

A variable that assumes a countable number of distinct values, often representing counts or categorical data.

Probability Distribution

A mathematical function that calculates the probability of different possible results occurring in an experiment.

Random Variable

A variable whose possible values are numerical outcomes of a random phenomenon.

Poisson Distribution

A discrete frequency distribution which gives the probability of a number of independent events occurring in a fixed time.