Exam 16: Human Health and the Environment

Hawaiian honeycreepers are _________.

Which one of the following illustrates interspecific competition?

Dung beetles live in regions where cattle graze,quickly burying and recycling cattle droppings.Because of the dung beetle's activities,breeding habitats and resources for disease- carrying flies are reduced,and the plants upon which cattle feed are nourished.The relationship between the dung beetles and the cattle is a type of____________ .

-Once they are a year old,many small songbirds such as goldfinches and house finches have approximately a 50% probability of surviving to the following year,regardless of the bird's age.Which survivorship curve in the figure best represents such birds?

Brown- headed cowbirds lay their eggs in the nests of other species of songbirds,relying upon the other species to raise their chicks.Many of these species unknowingly raise the cowbird chicks at the cost of their own reproductive success.The relationship between cowbirds and these other species of birds most closely matches which one of the following relationships?

A population's growth rate is determined by _________.

In a terrestrial food web,which of the following categories of organisms will have the highest total energy content and biomass?

All of the following are physical limiting factors affecting survival and growth of an organism except____________ .

Plants such as leafy spurge can double their population size every year in part because of their efficient production of large amounts of seeds.Populations that can double every year,such as leafy spurge,__________.

Dung beetles live in regions where cattle graze,quickly burying and recycling cattle droppings.Because of the dung beetle's activities,breeding habitats and resources for disease- carrying flies are reduced,and the plants upon which cattle feed are nourished.The relationship between the dung beetles and the disease- carrying flies is a type of___________ .

With regard to trophic structure,the rule of 10 states that_______ .

-Which of these lines depicts a population being affected by limited resources?

A keystone species __________.

A population would be expected to grow if __________.

Many strategies have been used to control leafy spurge,including the deliberate introduction of different species of flea beetles that feed on leafy spurge.Each flea beetle female may lay about 200 eggs in her only year of life.In places where flea beetle introductions have quickly established large populations that have grown and stabilized,a graph of the population growth of these beetles most likely would look like ___________ .

Why is the sea otter considered a keystone species in areas of the Pacific Ocean?

Which of the following represents a type of mutualism?

Purple martins are the largest species of swallow in North America.In the Eastern United States,they breed almost exclusively in large colonies in artificial martin houses and hollowed- out gourds hung by martin enthusiasts.Given this information,which of the following would be a valid inference?

Read the following scenario, and answer the questions below. In North America, a toxic weed called leafy spurge was accidentally introduced and has grown and spread rapidly, covering millions of acres in north- central United States and south- central Canada. Leafy spurge is generally avoided by cattle and horses and may be toxic to them. Thus, rangeland where leafy spurge has spread has been damaged by the invasion of this plant. -Flea beetles alone are unlikely to eliminate all of the leafy spurge in a region.Instead,the number of leafy spurge plants and the number of flea beetles in a particular community may stabilize.At such a point,the leafy spurge and flea beetle populations __________.

Read the following scenario, and answer the questions below. In North America, a toxic weed called leafy spurge was accidentally introduced and has grown and spread rapidly, covering millions of acres in north- central United States and south- central Canada. Leafy spurge is generally avoided by cattle and horses and may be toxic to them. Thus, rangeland where leafy spurge has spread has been damaged by the invasion of this plant. -Leafy spurge has spread across many U.S.states.If left uncontrolled in these states,leafy spurge populations will _________ .