Chapter 25, 4, 23, & 5

Middle latitude deserts can form where a mountain chain interrupts the prevailing winds, creating a rain shadow effect. As wind goes up and over the mountains, the water vapor it carries condenses, forming clouds and rain on the windward (facing the wind) side of the mountains and a desert on the leeward (sheltered from the wind) side, where the air (which now is very dry) descends the mountains. Label the accompanying diagram with the environmental conditions that occur when a rain shadow forms. Drag the appropriate labels to their respective targets. You do not need to use all labels.

-Condensation forms clouds and rain -wet climate -dry climate -desert -winward -leeward

Complete the following sentences about the defining characteristics of Earth's dry regions: Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is comlete before submitting your answer. Note that some terms will remain unused.

1. Regions where the climate is (semiarid) are known as steppe. 2. Thick (soil) is not found in deserts because there are fewer plants than in more (humid) climates. 3. A high rate of (evaporation) is often characteristic of a climate where there is not a steady flow of water and there are high temperatures. 4. A desert has a drier climate than a (steppe).

Drag the terrestrial biome on the left to the description given on the right. Not all terms will be used.

1. This cold, dry biome is populated by lichens and shrubs that can survive great seasonal variations in sunlight and temperature. tundra 2. In this hot, dry biome, populations of zebras, gazelles, and giraffes are concentrated around widely spaced watering holes. savanna 3. Also called steppe or prairie, this biome has been extensively developed for agricultural use due to its nutrient-rich soils. temperate grassland 4. Despite having lush vegetation and diverse biological communities, the soil in this biome has low nutrient content and cannot support long-term agriculture. tropical rainforest 5. This is the driest biome, where many plants have water-conserving features such as thick leaves and needles. desert 6. This biome is characterized by broad-leaved trees that lose their leaves each fall and remain dormant during winter. temperate deciduous forest

Drag the terms on the left to the appropriate blanks on the right to complete the sentences.

1. ___________ ecosystems include hydrothermal vent communities in the deep ocean bottom. open-ocean 2. Rocky shorelines that are home to sea stars, mussels, crabs, and anemones and experience fluctuating water levels are ___________ ecosystems. intertidal 3. ___________ ecosystems are being affected by the process of ocean acidification, which threatens their long-term existence. Coral reef 4. Floating brown algae that provide food and shelter for a diversity of animals characterize ___________ ecosystems. 5. ___________ ecosystems occur where fresh water from rivers mixes with saltier marine waters to produce a highly productive ecosystem with varying salinity levels. 6. Salt-tolerant grasses and shrubs dominate ___________ ecosystems, which occur on the coast at temperate latitudes.

The hair color of a hypothetical species of mammal is determined by a single gene. The black fur allele is dominant to the brown fur allele. If you cross two black-furred heterozygotes, what will be the ratio of fur colors in the offspring?

75 percent will have black fur, and 25 percent will have brown fur.

What is the best estimate of the total yearly precipitation in the region represented by this graph?

900 mm

Drag the appropriate label under each image to identify the evolutionary mechanism at work. Labels may be used more than once.

A. Gene flow B. Natural selection C. Natural selection D. Genetic drift E. Natural selection

__________ is any heritable behavioral, morphological, or physiological trait that maintains or increases the fitness of an organism under a given set of environmental conditions.

Adaptation

Dale Bosworth describes several reasons why America's national forests are not pristine landscapes. Which of the following reasons does he include in his essay?

American Indians have managed forests for thousands of years through the use of fire.

Matthew Koehler includes several statistics about impacts of logging in national forests. Which of the following statements describe an ecological impact of logging?

Approximately 50% of riparian areas require restoration due to logging and other land uses.

Which of the following statements about the decline of wetland ecosystems in the United States are true?

Between 2004 and 2009 wetland area declined by an estimated 62,300 acres.

The mechanism of natural selection, which helps explain how evolution occurs, was proposed by __________.

Charles Darwin

Freshwater wetlands are important in supporting A) waterfowl B) aquatic invertebrates. C) amphibians. D) all of the above.

D) all of the above.

Steven Herman describes the results of grazing on public lands as a "landscape holocaust." Which of the following conditions does he attribute to grazing?

Desertification of formerly productive ecosystems

Changes due to developmental plasticity are reversible.

False

Salt marshes occur mostly below the intertidal zone and are exposed only during very low tides.

False

The meiofauna of a sandy beach are organisms living on the surface of sediments.

False

True or False. In the example described in the tutorial, the red amoebas survived the catastrophic event, and all future generations of amoebas were red because the red amoebas had a higher reproductive rate than the blue ones.

False

Color is an inherited trait in beetles. If brown beetles move into a population from a nearby island, which of the following statements is correct?

Gene flow causes the frequency of the brown allele to increase.

__________ is/are the units of inheritance on which natural selection can act.

Genes

Remember that color is an inherited trait in beetles. Which of the following is an example of natural selection?

Green beetles leave more offspring than brown beetles because they are better at finding food.

Which of the following statements about the habitats of temperate climates is FALSE?

Herbaceous species of the temperate forests tend to flower just after the canopy regrows in the spring.

Which of the following statements about wetlands is FALSE?

Herbivores are rare in freshwater wetlands.

Which of the following statements best describes the relationship between the Hardy-Weinberg principle and the effects of natural selection?

If selection can be quantified, relative fitness values can be calculated and used to appropriately modify the Hardy-Weinberg equation.

Which of the following events could NOT be caused by a population bottleneck?

Increased population size

Which of the following statements about life in mudflats and sandy shorelines is true?

Infauna do not experience the same degree of fluctuation in temperature as epifauna or organisms on rocky shores.

Which of the following statements about the amoeba population described at the end of the tutorial is true?

It is more vulnerable to extinction due to lack of genetic variation.

What is an important attribute of the cordgrass Spartina?

It is salt-tolerant.

Which two months have the highest average temperature?

July and August

Both authors describe the unhealthy state of forests but describe very different solutions. Which of the following answers list Koehler's primary solution and Bosworth's primary solution?

Koehler: ecological restoration; Bosworth: active management (tree thinning)

Which of the following statements about mangroves is FALSE?

Mangrove forests develop in areas with low wave action and well-oxygenated mud.

Which of the following represents acclimation?

Marine lionfish are able to tolerate freshwater in estuaries.

You are studying the terpenes associated with peppermint, Mentha piperita, scent. Terpenes are aromatic compounds that give many plants their characteristic smell. You find a wild population of mint and collect samples. You find the following levels of menthone: 0.14 µmoles/leaf, 0.22 µmoles/leaf, 0.25 µmoles/leaf, 0.27 µmoles/leaf, and 0.34 µmoles/leaf. Which of the following can you say is true about menthone based on this study?

Menthone content is a quantitative trait.

You have joined a fraternal ecological organization with an unusual initiation ritual. They drop you off in a distant biome with limited supplies and you must camp there for two days, study the biome and give a presentation at the first meeting of the organization. You find yourself in a warm area dominated by evergreen shrubs that seem to grow more in the wetter winter months than in the summer. You also notice evidence of fires in the area. The title of your presentation could be __________.

My Time in the Mediterranean Climate: Enjoying a Temperate Shrubland

What is the best description of the pattern of precipitation shown by this graph?

Precipitation is greatest in the spring and summer.

Which of the following statements about tidal pools is FALSE?

Rainfall has a major effect on the organisms found in deep tidal pools.

Although Koehler and Bosworth disagree about the role of logging in U.S. national forests, their essays suggest one potential point of agreement. Which of the following statements would both authors support?

Removing some trees from forests can reduce the threat of wildfire in protected areas.

Which of the following statements about tropical savannas is FALSE?

Savannas show little interannual variation in total precipitation. Submit

Deserts are found in both subtropical latitudes and middle latitudes. Subtropical deserts form in areas of high pressure that stretch worldwide as a part of global atmospheric circulation. In this band of latitude, dry air descends from high in the atmosphere. They often have the appearance that you would expect of a desert with clear skies, sunshine, and very dry conditions. Middle latitude deserts form in the interiors of continents, far from the ocean or other sources of moisture and anywhere land is cut off from sources of moisture. Not all deserts are the same. Refer to the map below, and sort the desert features by the type of desert in which they are most common. Drag the appropriate items to their respective bins.

Subtropical desert: - Form due to persistent high atmospheric pressure. - Location is due to global atmospheric patterns. Middle latitude desert: - Characterized primarily by minimal precipitation. - Rain shadows may form here mountains cross prevailing winds Uncommon desert features: - Precipitation never occurs. - Plants do not grow.

Many researchers have indicated that the loss of mangrove forests due to conversion to shrimp farms contributes to the intensity of wave action on beaches and may have even led to the intensity of some recent devastating tsunamis. Which of the following could be a good project that would allow you to gather data to test this hypothesis?

Survey reports of the intensity of wave action and height of flood tides on coastlines where (1) mangroves are intact and (2) mangrove forests have been converted to shrimp farming.

Which of the following statements about forest management is FALSE?

Sustained yield in a forest management system allows for rapid rotation and turnover rates of 10 years or less.

Richard Knight describes the public and private land in the West. Which statement represents one aspect of this landscape?

The families that hold Bureau of Land Management and US Forest Service grazing permits also own more than 100 million acres of private land.

If there are two alleles of a gene controlling coat color in a population of mice and the frequency of the dominant allele is 0.3, which of the following must be true?

The frequency of the recessive allele is 0.7.

Which of the following statements about rocky shoreline communities is FALSE?

The infralittoral fringe is exposed only during ebb tides, every two weeks.

When one examines the global distribution of tundra ecosystems, there are inconsistencies with the expected latitudinal distribution of the tundra biome. In South America there is a thin strip where these biomes are found from close to the equator almost to the southern tip of the continent. How are these found in these very different latitudes?

The line observed on the map corresponds to the Andes, a very tall mountain range.

Which of the following statements is true?

The lowest fringes of the intertidal zone are subjected to the lowest amount of variation in environmental conditions.

Which of the following statements best describes the relationship between fitness and selection coefficient (s)?

The stronger the selection against a given genotype, the lower the fitness associated with that genotype.

Which of the following statements about temperate grasslands is true?

The vegetation of temperate grasslands depends on the predictability and amount of rainfall.

What is true regarding sandy shores?

Tidal patterns exist.

A trait cannot be subject to natural selection unless it is heritable.

True

Bird and mammal predators are more common in salt marshes during low tide than during high tide.

True

Genes are arranged in threadlike bodies called chromosomes.

True

Shoreline communities exhibit strong zonation.

True

The characteristics maximize the fitness of an individual under one set of environmental conditions generally limit its fitness under a different set of conditions.

True

What is the best description of the yearly temperature range shown by this graph?

Winters are cold and summers are hot.

You are a U.S. senator who plans to introduce an updated version of the Organic Administration Act of 1897. What scientific information would be useful for rewriting the original law?

You are a U.S. senator who plans to introduce an updated version of the Organic Administration Act of 1897. What scientific information would be useful for rewriting the original law?

In temperate regions dominated by deciduous forests, seasonal changes result in __________.

a larger leaf area index during summer months.

A gene is

a stretch of DNA coding for a polypeptide chain (sequence of amino acids). Submit

The process by which one species gives rise to multiple species that exploit different features of the environment is called __________.

adaptive radiation

What does the red line on the graph represent?

average temperature (°C)

The major food sources for both deposit-feeding and filter-feeding organisms are

bacteria

The intertidal zone is defined by

being continually exposed and submerged by the ocean.

Evolution is best described as __________.

changes in gene frequencies within populations over time

The climate diagrams below represent which of the following biomes?

conifer forest

Which of these is the largest terrestrial biome on Earth?

coniferous forest

Dry seasons in the tropics are analogous to temperate winters because __________.

deciduous trees in both locations lose their leaves and cease photosynthetic activity

Which of these biomes is characterized by little rainfall?

desert

If birds with larger beaks are favored by the environment, it is likely that ________ selection will occur.

directional

An allele that completely masks the effect of another allele is considered

dominant

Which of the following are causes of evolutionary change?

gene flow natural selection genetic drift mutation

The __________ of a population represents its total genetic variation.

gene pool

The evolution of populations due to chance is

genetic drift.

In a population with brown and green alleles for color, genetic drift

has more effect on the evolution of a small population.

In tropical rain forests, high precipitation and consistently high temperatures result in __________.

high rates of decomposition and nutrient cycling

The higher-elevation areas of a salt marsh have __________ salinity and a(n) __________ input of nutrients that result from a lower tidal exchange rate than in the lower areas of the marsh.

higher; decreased

The tongue length of an animal is controlled by two alternative alleles at a single locus, L (long) and l (short). If an individual has parents that are both homozygous dominant, it will be

homozygous dominant with a long tongue.

Negative consequences of inbreeding are known as __________.

inbreeding depression

The __________ zone lies between the high tide and low tide lines.

intertidal

Intertidal mud flats in tropical regions are typically composed of

mangrove forests or mangals.

The __________ are tiny organisms that live between grains of sand on sandy shores.

meiofauna

Generation-to-generation change in the allele frequencies in a population is _____.

microevolution

What do the blue bars on the graph represent?

monthly precipitation

What is formed when an accumulation of peat rises above the surrounding landscape?

moors

Salt marshes

occur mostly in temperate latitudes.

What are epifauna?

organisms living on the sediment surface of sandy and muddy shores

The expression of different phenotypic traits for a given genotype under different environmental conditions is referred to as

phenotypic plasticity.

Cordgrass (Spartina), glassworts (Salicornia), and spearscale (Atriplex) are types of plants commonly found in

salt marshes.

When the amount of water in soil exceeds what the pore space can hold, the soil is

saturated

On a rocky intertidal shoreline, the __________ zone lies below the infralittoral fringe.

subtidal

Freshwater wetlands dominated by woody vegetation are referred to as

swamps

Which of the following biomes does this climatograph most likely represent?

temperate grassland

What are the two major factors determining the distribution of terrestrial biomes?

temperature and rainfall

If color is an inherited trait in beetles, and birds are more likely to eat brown beetles than green beetles,

the frequency of the green allele will increase.

The fitness of an individual is measured by

the proportionate contribution it makes to future generations.

Knight describes three "inescapable truths" about today's West. He implies that _______.

the public ultimately benefits because ecologically rich private lands are kept open if ranchers can use public land for grazing

In salt marshes, predatory fish move in when

the tide is high.

Which biome is characterized by an extensive canopy that allows little light to penetrate to the ground and by the presence of epiphytes?

tropical rain forest

Which biome is characterized by the presence of permafrost?

tundra

What are marshes?

wetlands dominated by emergent herbaceous vegetation