AGRI 331 Exam 2

According to the graph, the addition of additional species to an ecosystem: Only increases ecosystem function with the addition of particular species Is redundant after a certain number of species is added Has no impact on ecosystem function Increases ecosystem function at an equal rate

Is redundant after a certain number of species is added

Which statement is true of artificial selection ? It is essentially the same process as natural selection It is related to the domestication of animals, but not to agriculture It is fundamentally different from natural selection It was elaborated as a theory long after natural selection was first discussed

It is fundamentally different from natural selection

What is the relationship between temperature and dissolved oxygen in water? The higher the temperature, the more dissolved oxygen there is in the water. The higher the temperature, the more acidic the water is. There is no relationship between temperature and dissolved oxygen. The lower the temperature, the more dissolved oxygen there is in the water.

The lower the temperature, the more dissolved oxygen there is in the water.

A pond in a deciduous forest becomes filled with silt and organic matter. As this area undergoes ecological succession, which of the following represents the most likely order, from earliest to latest, in which the types of vegetation above will appear? 1. Tall perennial herbaceous plants 2. Climax trees 3. Short-lived r-selected plants 4. Shrubs and pioneer trees 3,4,1,2 1,3,4,2 1,3,2,4 1,2,3,4 3,1,4,2

3,1,4,2

Which of the following statements concerning adaptations is a TRUE statement? A genetically caused change in an individual's phenotype may or may not be an adaptation depending upon the environment. A genetically caused change in an individual's phenotype would be considered an adaptation if it decreased the individual's ability to survive, and decreased the individual's ability to reproduce.

A genetically caused change in an individual's phenotype may or may not be an adaptation depending upon the environment.

Which of the following individuals is most fit in evolutionary terms? A woman of 80 who has one adult offspring A 100-year-old man with no offspring A child who does not become infected with any of the usual childhood diseases, such as measles or chicken pox A woman of 40 with seven adult offspring A childless man who can run a mile in less than five minutes

A woman of 40 with seven adult offspring

The graph depicts the frequency of expression of the range of leg lengths in a population of grazing animals. In this species, leg length is directly related to speed, which is a heritable characteristic. These grazers are being preyed on by a newly introduced species of swift-running predator. Which of the following graphs represents the range of expression most likely to result from the selection pressure over a long period of time?

A. Graph that is right skewed

Which of the following is not a prerequisite for natural selection's operation (Ch 14)? An innate desire to change More offspring than can possibly survive Competition for resources Differential reproduction

An innate desire to change

When choosing animals to integrate into a farming plan how should they be chosen (intercropping principles)? Chose breeds based on current market trends Chose breeds that will fit your system Select breeds with the most money making potential should be chosen Select breeds that with highest quality carcass traits

Chose breeds that will fit your system

A student placed 20 tobacco seeds of the same species on moist paper towels in each of two petri dishes. Shortening of cells in the stem in response to the lack of light Enhancement of stem elongation by light Elongation of seedlings in response to the lack of light Genetic differences between the seeds

Elongation of seedlings in response to the lack of light

Which Factor is significant? Factor 1 and interaction Factor 1 only Factor 2 only Interaction Factor only Factor 2 and interaction

Factor 1 only

ll of the following are thought to be negative effects of climate change EXCEPT: You Answered Worldwide rise in temperature A rise in sea level Frequent earthquakes Premature melting of the ice caps

Frequent earthquakes

How does the greenhouse effect work? Greenhouse gases directly warm oceans and cause dramatic weather. Oceans absorb greenhouse gases, which cause the Earth's temperature to rise. Greenhouse gases reflect the sun's energy, causing it to warm the Earth. Greenhouse gases absorb the sun's energy, slowing or preventing heat from escaping into space.

Greenhouse gases absorb the sun's energy, slowing or preventing heat from escaping into space.

Which of the graphs below represent(s) selection that may lead to the emergence of a new species? Y axis is number of individuals and X axis is a trait (e.g. increasing size of legs) II or III I, II, or III I only III only I or III

I or III

What are the four main gases in Earth's atmosphere? What are the proportions of each?

Nitrogen (N2, 78%), Oxygen (O2, 21%), Argon (Ar, 1%) and water (H2O, 0 - 7%)

In replicated experiments, plots are planted with flax seeds in densities of 60, 1,440, and 3,600 per square meter, respectively. The factors of soil, water, and light are similar of each plot. Dry weights of the mature plants are obtained. Increased densities in this experiment produced which of the following results in plants? Normally distributed weights Etiolated leaves and stems Random expression of some traits Reduced genetic variability Reduced individual biomass

Reduced individual biomass

Which is NOT an example of natural selection? Plants with thorns are less likely to be eaten by herbivores than other members of the same species that lack thorns. Weed populations in farmers' fields develop resistance to herbicides Scientists breed cows that give greater amounts of milk than their ancestors. Bacterial populations in hospitals develop resistance to drugs used to combat infection by them. Female fish that produce more eggs leave more offspring than those that produce fewer eggs.

Scientists breed cows that give greater amounts of milk than their ancestors.

The dotted line marked K indicates which of the following The carrying capacity of the population The maximum number of offspring that each pair of parents can produce in a single year The intrinsic rate of reproductive increase of the population The proportion of a population that can be removed without destroying its ability to maintain a stable population size The annual rate of growth

The carrying capacity of the population

Along the length of the Feather River there exists a species of salmon. In order to provide electricity to area homes, a hydroelectric dam is built that separates the lower river area from a newly formed lake above (Lake Oroville). After many, many years, the salmon in the river and lake are sampled and found to be phenotypically very different. Which of the scenarios listed below is the best hypothesis to explain the microevolutionary changes observed?

The dam caused different environmental conditions to be formed in the lake versus the river, and natural selection selected for the best-fit organisms in both environments.

What is the BEST explanation of why the moth population changed during the industrial revolution? The moths needed to get darker to hide from the birds. The dark moths must have survived better in the sooty environment The soot from the burning coal made the moths get darker and darker.

The dark moths must have survived better in the sooty environment

Agroecosystems tend to have more pest outbreaks than natural ecosystems for all the following reasons, EXCEPT There are more trophic levels in agroecosystems than natural ecosystems. There is an abundance of nutrient-rich food available. The number and diversity of beneficial organisms that can control the pests is relatively small. The food is usually available in large quantities over a short period of time.

There are more trophic levels in agroecosystems than natural ecosystems.

The greenhouse effect refers to: -A naturally-occurring process which keeps the Earth warm enough for life to be possible -The ozone layer, which allows heat to pass through to the Earth, but not to escape -A global temperature increase due to the number of greenhouses being built, especially in the industrialised world -When the Earth's atmosphere becomes thick with gases and substances which trap the sun's radiation, making the Earth warmer.

When the Earth's atmosphere becomes thick with gases and substances which trap the sun's radiation, making the Earth warmer.

Which graph depicts the intermediate disturbance hypothesis ?

Z. Bell Shaped Curve

An acid is _____. (Lab 4) -a material that resists pH changes -any compound with a pH -any compound that accepts hydrogen ions -a compound that donates hydrogen ions to a solution -a solution with a pH between 7 and 14

a compound that donates hydrogen ions to a solution

Diversity is of value in agroecosystems for all the following reasons, EXCEPT increases the opportunities for beneficial relationships (eg. mutualism) when livestock are integrated into agroecosystems, beneficial interactions increase. increases resource use efficiency a diverse agroecosystem facilitates heavy machinery use. a diversity of crop assemblages can create microclimates favorable to beneficial predators

a diverse agroecosystem facilitates heavy machinery use.

At what level does a LER say that there is a benefit to intercropping (intercropping principles)? below 1.0 above 1.0 At 0.9 below 0.5

above 1.0

A pH reading of 2 means the water is: (lab 4) acidic hard alkaline soft

acidic

A variation that helps an organism be better suited for its environment is a(n) __________ . adaptation species element hypothesis

adaptation

Species that put all of their effort into rapid growth, maturation, and reproduction during favorable conditions are most likely (Ch 13): ruderals competitors stress tolerators

competitors

Practices that directly decrease soil organic matter include all of the following, EXCEPT: burn crop residues decrease the amount of residues on the soil increase tillage decrease nitrogen fertilization

decrease nitrogen fertilization

The loss of over 20,000 native varieties of rice in India is an example of somaclonal variants. genetic erosion. lodging. an increase in soil salinity. germplasm.

genetic erosion.

Pioneer species such as __________ begin to build up soil in primary succession (Ch 17). old deciduous forests shrubs grasses pine trees

grasses

Two of the premises that form the basis of Darwin's concept of natural selection are uniformitarianism and catastrophism geographic and reproduction isolation dominance and recessiveness ecotype and race heritability and fitness

heritability and fitness

The largest carbon reserves on earth are ___. in the ocean in animals in rocks in the atmosphere in plants

in the ocean

The genetic diversity contained in the gene pool of self-pollinating individuals is (Ch 14): of smaller size than for cross-pollinating individuals. of greater size than for cross-pollinating individuals. of the same size than for cross-pollinating individuals.

of smaller size than for cross-pollinating individuals.

All of the following may result in the loss of genetic diversity except __________(Ch 14). population fragmentation loss of habitats directed breeding practices reduction in population size introduction of a new race into an established population

introduction of a new race into an established population

Climate change is causing all the following EXCEPT ________.(Groundwater Recharge) more intense droughts less volatile precipitation reduced snowpack higher runoff

less volatile precipitation

Key challenges to expanding groundwater recharge include all the following EXCEPT _________. (Groundwater Recharge) most available flows occur in the state's wetter areas, while most overdraft occurs in dry areas. the timing of large storms-which create "big gulps" of water during a few days or weeks complicates water distribution. most surface water contains nitrate levels above 10 ppm with can contaminate groundwater supplies.

most surface water contains nitrate levels above 10 ppm with can contaminate groundwater supplies.

The appearance of new insect varieties that are resistant to insecticides is an illustration of ... natural selection thigmotropism ecological succession adaptive radiation

natural selection

The appearance of new insect varieties that are resistant to insecticides is an illustration of ... natural selection adaptive radiation ecological succession thigmotropism

natural selection

Which is the correct order of processes from longest to shortest time to direct result? natural selection, genetic engineering, artificial selection natural selection, artificial selection, genetic engineering artificial selection, natural selection, genetic engineering They are all the same.

natural selection, artificial selection, genetic engineering

When antibiotics were first introduced they killed almost all bacteria, but varieties have now evolved which are resistant to antibiotics. Which is the final event that occurred during this process. resistant organisms reproduced resistant organisms occurred by mutation resistant organisms survived while others were killed the use of antibiotics began

resistant organisms reproduced

Plants adapted to conditions of frequent disturbance (once or every few years) in resource abundant environments are called (Ch 13): ruderals. competitors stress tolerators

ruderals

Unlike the other mechanisms that can cause microevolution, natural selection always works in concert with ______ to make organisms more fit. totally random mating the environment a small population of organisms migrating organisms

the environment

The decimation of public resources through the selfish actions of individuals is known as the tragedy of the commons geographical fragmentation of regions spawning biomass economies of association

tragedy of the commons

Competitive exclusion can be best defined as : the creation of separate ecological niche by a new species when competition results in the elimination of a particular limiting resource when one species shares limiting resources with another the division of resources when one species outcompetes and eliminates another

when one species outcompetes and eliminates another