Biodiversity Chapter Quiz 10

The term 'biodiversity' refers to a variety of species on Earth. Biodiversity encompasses the total number of different species of plants, animals, and microorganisms, as well as the genetic diversity within each species. It also includes the diversity of ecosystems and habitats where these species exist. Biodiversity is important for the overall health and stability of ecosystems, as each species plays a unique role in maintaining the balance and functioning of the natural world.

A mass extinction refers to the extinction of a large number of species within a relatively short period of time. This event is characterized by a significant loss of biodiversity and can have severe consequences for the environment. Mass extinctions have occurred throughout Earth's history, such as the extinction of the dinosaurs. It is not a benefit to the environment, but rather a concerning phenomenon that disrupts ecosystems and can take millions of years for biodiversity to recover.

Keystone species are crucial for the functioning and stability of an ecosystem. They have a disproportionately large impact on their environment compared to their abundance. These species play a vital role in maintaining biodiversity, regulating populations, and influencing the structure of their habitat. Their loss can lead to significant disruptions in the ecosystem, affecting other species and ecosystem processes. Therefore, the term "keystone" is used to describe the importance and indispensability of these species.

The correct answer is "are insects." This is because insects make up the largest group of living species known to science. With over a million described species, insects outnumber all other animals combined. They are found in various habitats worldwide, ranging from forests to deserts. Insects play crucial roles in ecosystems as pollinators, decomposers, and as a food source for other animals. Their incredible diversity and adaptability have allowed them to thrive in almost every corner of the planet.

The correct answer is that the international trade of ivory was banned worldwide. This is because the Convention on International Trade in Endangered Species (CITES) made efforts to combat the poaching of elephants and protect them from extinction. As a result, the international community agreed to ban the trade of ivory globally in order to discourage poaching and reduce the demand for ivory products. This ban aimed to protect the elephants and preserve their population.

When sea otters disappeared from the Pacific coast of North America, the number of sea urchins in the kelp beds increased. Sea otters are natural predators of sea urchins, and their absence allowed the sea urchin population to grow unchecked. As a result, the increased number of sea urchins began to feed on the kelp, leading to a decline in kelp beds. This shift in the ecosystem caused the area to become overrun with brown seaweed, as the kelp was no longer able to thrive and maintain its dominance.