Exam 18: An Introduction to Ecology and the Biosphere

Please read the following scenario to answer the following questions. Salmon eggs hatch in freshwater streams and, during their first year of life, the young salmon migrate distances up to 1,000 km in order to reach the ocean. Here they spend up to 5 years where they feed and grow, acquiring more than 95% of their biomass. During the summer of their maturing year, they begin the long journey back to their home streams to spawn. Although it is still uncertain how salmon navigate back to their spawning grounds, current hypotheses suggest that they have a highly developed sense of smell that allows them to remember odors they encountered on their migration to the ocean. They then use these odors to help them navigate back to the streams where they were born. At the spawning grounds, females use their tails to form a hollow cavity in the stream gravel where they lay up to 8,000 eggs. The males fertilize the eggs, and both adults typically die soon thereafter. -The physiological response that allows salmon to survive in fresh water,then in salt water,and then fresh water again is an example of ________.

Which of the following is NOT a cause of increasing CO₂ levels?

What is a population?

Examine the figure below.Which part of Earth receives the greatest intensity of solar radiation?

The Sahara Desert and the Negev Desert belong to the same ________.

Temperature increases due to global warming have been greatest ________.

Which of the following is a behavioral response to environmental variability?

What is one important difference between savannas and temperate grasslands?

Please read the following scenario to answer the following questions. Salmon eggs hatch in freshwater streams and, during their first year of life, the young salmon migrate distances up to 1,000 km in order to reach the ocean. Here they spend up to 5 years where they feed and grow, acquiring more than 95% of their biomass. During the summer of their maturing year, they begin the long journey back to their home streams to spawn. Although it is still uncertain how salmon navigate back to their spawning grounds, current hypotheses suggest that they have a highly developed sense of smell that allows them to remember odors they encountered on their migration to the ocean. They then use these odors to help them navigate back to the streams where they were born. At the spawning grounds, females use their tails to form a hollow cavity in the stream gravel where they lay up to 8,000 eggs. The males fertilize the eggs, and both adults typically die soon thereafter. -At different times in their lives,salmon can be found in all of the following EXCEPT ________.

Which of the following actions would increase your carbon footprint?

What fraction of Earth's surface has been altered by human use?

Which of these is a community?

Malaria is an infectious disease transmitted to humans from a parasite that infects mosquitoes that feed on humans.World health officials have concerns that climate change may impact the transmission of malaria into tropical highland areas in Africa.If these concerns turn out to be valid,they would be evidence for which of the following?

Permafrost,or permanently frozen subsoil,characterizes ________.

Which of these biomes are maintained by fire?

Scientists have documented that spring seasons starting earlier due to climate change have resulted in some caterpillar species beginning their maturation stage earlier than normal.There are bird species that need the caterpillars to feed their chicks.However,since the caterpillars are maturing before the chicks hatch (and therefore cannot be used for chick food),the birds are experiencing a drop in their lifetime reproductive success.Interestingly,scientists have also documented that the individual birds that are best able to change when they lay their eggs to align with earlier spring seasons have the greatest lifetime reproductive success.These phenomena are examples of ________.

An effect of deforestation has been to ________.

Please read the following scenario to answer the following questions. CO₂ is not the only greenhouse gas that impacts global climate change. Other greenhouse gases (GHGs) may be equally or more effective than CO₂ at trapping heat on Earth. Climate scientists determine how much a GHG may impact global warming based on two factors: the efficiency with which a GHG absorbs energy (i.e. traps heat on Earth) and the length of time (in years) that the gas remains in the atmosphere. A unit of measurement called the Global Warming Potential (GWP) is used to describe how much energy a GHG absorbs over a specific period of time (100 years is a standard time frame). All GWP values of GHGs are compared to the GWP of CO₂, which is given a value of 1. -has a GWP over 20 times higher than CO₂.However,CH₄ emitted today lasts for only about a decade in the atmosphere,while the GWP of CO₂ can last for thousands of years.What is a possible reason that CH₄ can have such a high GWP as compared to CO₂?

In an aquatic ecosystem,what name is given to the region where photosynthesis can occur?

Which of the following is NOT a result of global warming?