Biology 1409: Chapter 19 Smartwork Homework

As global warming continues to warm the planet, states at mid-latitude in the United States will likely experience a shift from a temperate climate to a subtropical climate, which is characterized by hot, humid summers and mild winters. If this results in a northward expansion in the range for Aedes aegypti, how would that likely change the carrying capacity for the mosquito's habitat in the United States?

It would increase carrying capacity.

These population data (in the table below) show historical trends between 2013 to 2015 . Rank the nations by their doubling time.

Longest 1 - Japan 2 - Netherlands 3 - United States 4 - India 5 - Pakistan 6 - Nigeria Shortest

Which of the following best describes the relationship between lynx and hare?

Lynx and hare populations demonstrate cyclical fluctuations due to density-dependent interactions.

What would likely happen to population size and carrying capacity if the number of breeding sites for a mosquito population (standing water) increased after a flooding event? For example, think of Houston after being hit by Hurricane Harvey.

Population size would increase and carrying capacity would also increase.

One critical component in the efforts to stop the transmission of the Zika virus in Brazil, and then later in the United States, was a direct result of understanding the population ecology of mosquitoes. What action was taken to reduce mosquito populations that directly reduced their ability to reproduce as a result of changing carrying capacity?

The amount of standing water was reduced to reduce the breeding habitats available to the mosquitoes, resulting in fewer offspring and reduced populations.

What determines carrying capacity for a population in a given environment?

any limiting resource

A population can grow in size when the number of _____ and/or ________ increases.

births; immigration

The total number of individuals of a species per unit area is referred to by ecologists as population

density.

The Amur leopard, the world's rarest cat, saw a remarkable recent increase in the size of its population from only 30 individuals in 2007. The population roughly doubled between 2007-2015 and has stabilized around 57-60 individuals. These cats only live in an area that straddles Russia and China, but they mostly live in Russia's Land of the Leopard National Park. There are no other populations of this magnificent animal. What caused the population to increase?

increase in births

Increasing concentrations of food sources causes carrying capacity to

increase.

Which statement best describes the population growth illustrated by this S-shaped curve?

logistic growth where the population grows exponentially at first and then stabilizes

Dr. Cherry monitors populations of the threatened plant species Boltonia decurrens, a species that only lives in the Illinois River Valley in Illinois. She visits each population annually to count the number of plants and monitor the populations. This type of study is known as

population ecology.

For which population could an ecologist most easily determine the accurate population density?

purple coneflowers at Konza Prairie Biological Station

Examine the figure below. Which population dynamic is being affected?

birth

A majority of scientists agree that the carrying capacity of Earth for the human population is approximately 9-10 billion people. The human population was 7 billion in 2014 and 7.9 in 2021. At current population growth rates, in approximately what year will we reach carrying capacity?

2050

Individuals can leave their population through which two processes?

B. emigration D. death

In 1993, a catastrophic flood occurred in the Mississippi River Valley that resulted in $15 billion in damage. Known as "The Great Flood," it provided biologists a chance to study the population dynamics of plant species living in the floodplains. Not surprisingly, many areas that were flooded for a prolonged period of time were completely stripped of vegetation, leaving behind mud flats. The decurrent false aster (Boltonia decurrens), a threatened plant that had dropped to perilously low numbers, needs floods to wipe out competing vegetation and create open mud flats for its seeds to colonize. After the flood, population numbers increased from a few thousand plants to over a million plants. This is an example of which process(es)?

C. density-independent population change D. irregular population fluctuation

After examining the graphs showing population sizes of the snowshoe hare (an important food source for predators) and the lynx (a predator that likes to eat snowshoe hares), how would you correctly describe the fluctuations seen in their populations?

Cyclical population fluctuation

Does this graph (shown here below again), represent a density-independent or density-dependent limit on the number of plants?

Density-dependent

Population density is determined by calculating the number of organisms per unit area. Calculate the density of elephants per square mile in the Serengeti-Masai Mara for 1986 and 2014. What happened to elephant density in this area?

Elephant density increased from 0.10 elephants per square mile in 1986 to 0.37 elephants per square mile in 2014.