Bio 2 3rd

Which interaction is advantageous to both populations? a. commensalism b. mutualism c. parasitism d. competition e. predation

b. mutualism

Which concept reflects the increasing numbers of species present in an area that includes a wide variety of habitats, vegetation types, and small-scale environments? a. beta-diversity b. conservation biology c. the species-area relationship d. landscape ecology e. alpha-diversity

a. beta-diversity

The major cost to plants for having cuticle-covered epidermis in the shoot system to reduce water loss is reduced ____ uptake. a. carbon dioxide b. potassium c. oxygen d. calcium e. nitrogen

a. carbon dioxide

Which airborne pollutant contributes to global warming? a. carbon dioxide b. carbonic acid c. ozone d. mercury e. sulfur dioxide

a. carbon dioxide

A population of 100 animals undergoing logistic growth has rmax = 0.4 and K = 102. Given that r = r = rmax(K - N)/K, calculate the value of r. a. 0.0078 b. 0.792 c. 0.078 d. 0.99 e. -0.580

a. 0.0078

Why should humans consider eating "lower on the food chain"? a. Energy efficiency is greater when passed through fewer trophic levels. b. We digest and assimilate meat more efficiently than plant material. c. We digest and assimilate plant material more efficiently than meat. d. Many regions exist that support vegetation suitable only for feeding large herbivores. e. No biological reaction is 100% efficient.

a. Energy efficiency is greater when passed through fewer trophic levels.

Which statement is true regarding typical plant development? a. Growing tips and zones are present throughout a plant's life, and plant bodies do not have a fixed final size. b. Final plant form is not influenced by the environment, and growing tips and zones are present throughout a plant's life. c. Plant bodies do not have a fixed final size, and final plant form is not influenced by the environment. d. Growing tips and zones are present throughout a plant's life, and final plant form is not influenced by the environment. e. Plant bodies have a fixed final size, and final plant form is influenced by the environment.

a. Growing tips and zones are present throughout a plant's life, and plant bodies do not have a fixed final size.

Which statement best summarizes the results of the experiment by Damschen and her colleagues on the effect of landscape corridors on species richness? a. Over time, the number of native species harbored by habitat patches with landscape corridors was increasingly greater than in isolated habitat patches. b. The number of native species increased over time in isolated habitat patches but not in those connected by corridors. c. Habitat patches with landscape corridors are at higher risk of encroachment by exotic species than are isolated habitat patches. d. The number of exotic and native species decreased in patches connected by landscape corridors. e. The number of both native and exotic species increased over time in habitat patches that were connected by landscape corridors.

a. Over time, the number of native species harbored by habitat patches with landscape corridors was increasingly greater than in isolated habitat patches.

During daylight hours, primarily ____. a. Pr absorbs red light and is converted to Pfr b. Pfr absorbs red light and is converted to Pr c. Pfr is converted to Pr d. Pr absorbs far-red light and is converted to Pfr e. Pfr absorbs far-red light and is converted to Pr

a. Pr absorbs red light and is converted to Pfr

Why do early successional stages harbor many r-selected species? a. They produce many small seeds that colonize open areas. b. They are not damaged by disturbances. c. They grow slowly. d. They are long-lived. e. They often require shade.

a. They produce many small seeds that colonize open areas.

Guard cells contain chloroplasts. a. True b. False

a. True

Imagine that you own a nursery and you want to reduce the chance that plants you ship will suffer from shipping damage. You should you apply ____ to the plants before shipping. a. abscisic acid b. ethylene c. gibberellins d. cytokinins e. oligosaccharins

a. abscisic acid

Imagine that you are a farmer who chose not to rotate your crops with soybeans even though the local extension agent recommended that you do so. Which deficiency symptom in your crops should indicate to you that the extension agent's advice was correct? a. chlorosis in older leaves and stunted growth b. purplish veins c. pale green, rolled, or cupped leaves d. chlorosis and mottled or bronzed leaves e. burned leaf edges and curled, mottled, or spotted older leaves

a. chlorosis in older leaves and stunted growth

When subtropical forest is cleared, which biome is most likely to replace it? a. desert with poor, eroded soil b. cropland ideal for agriculture c. chaparral with grass and low bushes d. young forest with the same species e. grassland suitable for grazing

a. desert with poor, eroded soil

The ____ prevents important substances in the xylem from leaking into the root cortex. a. endodermis b. primary xylem c. pericycle d. root hairs e. tonoplasts

a. endodermis

If the y of surrounding soil is higher than that in living root epidermal cells, then water should ____. a. enter the root cells, making them turgid b. enter the root cells, making them flaccid c. leave the root cells, making them turgid d. none of these accurately describe water movement e. leave the root cells, making them flaccid

a. enter the root cells, making them turgid

Many fully differentiated plant cells are totipotent, meaning that they ____. a. have the potential to form a whole, fully-functional plant b. will grow roots if they touch the ground c. can undergo meiosis d. will perform photosynthesis if exposed to sunlight e. can fertilize an egg

a. have the potential to form a whole, fully-functional plant

The intrinsic rate of increase is ____ for bacteria, protists, and animals with short generation times and ____ for those with long generation time. a. high; low b. low; constant c. high; constant d. constant; low e. low; high

a. high; low

The KN-1 gene in maize is normally expressed in ____. a. in apical meristems, where it maintains the undifferentiated state b. in apical meristems, where it initiates the process of differentiation c. in primary meristems, where it initiates the process of differentiation d. in lateral meristems, where it initiates the process of secondary growth e. in primary meristems, where it maintains the undifferentiated state

a. in apical meristems, where it maintains the undifferentiated state

Suppose you are culturing tobacco callus in a Petri dish at a 10:1 ratio of auxin to cytokinin. To promote only shoot development you would ____. a. increase the cytokinin ratio b. reduce the auxin level significantly and increase the cytokinin level slightly c. grow the tobacco in the light d. increase the auxin ratio e. grow the tobacco in the dark

a. increase the cytokinin ratio

Studies of a soybean plant (Glycine max) and the bacterium Bradyrhizobium japonicum have shown that the tip of a root hair curls toward the bacterium in response to ____. a. nod gene products produced by the bacterium b. nitrogen fixation by the bacterium c. a flavonoid produced by the bacterium d. a flavonoid released by soybean roots e. nod gene products produced by soybean roots

a. nod gene products produced by the bacterium

Ecologists use compartment models to describe ____. a. nutrient cycling b. species richness c. detrital food webs d. grazer food webs e. inputs of solar energy

a. nutrient cycling

Symptoms of nitrogen deficiency in plants first appear in _____. a. older leaves b. the stem c. roots d. younger leaves e. seeds

a. older leaves

The direction of expansion for a plant cell is determined primarily by ____. a. orientation of cellulose microfibrils b. gravity c. location of the cell plate d. the direction of cell division e. the direction to the nearest meristem

a. orientation of cellulose microfibrils

Water can move inside a root water mainly via ____. a. osmosis b. guttation c. symport d. facilitated diffusion e. bulk flow

a. osmosis

In vascular plants, sugars are transported throughout the plant by ____. a. phloem b. collenchyma c. xylem d. parenchyma e. sclerenchyma

a. phloem

A plant responds to changes in photoperiods by activation of _____, which drives _____ to stimulate cellular responses to light. a. phytochromes; calcium-binding proteins b. transcription factors; abscisic acid c. red light; blue light d. phytochromes; auxins e. cryptochromes; PR proteins

a. phytochromes; calcium-binding proteins

Which interaction is advantageous for one species, but has a negative effect on the other? a. predation, herbivory, and parasitism b. predation only c. herbivory only d. parasitism only e. mutualism only

a. predation, herbivory, and parasitism

The ability of roots to absorb mineral ions and water is maximized by _____. a. producing large quantities of root hairs throughout the life of the plant b. producing a single type of ion channel that is able to take up many types of ions c. producing deep taproots in arid regions d. producing chemicals that deter infection by mycorrhizal fungi e. increasing the diameter of roots as they age, to accommodate more nutrients

a. producing large quantities of root hairs throughout the life of the plant

In the logistic model of population growth, what is expected to happen to r when N = K? a. r = 0 b. r > 0 c. r becomes negative d. r will approach 1 e. r will approach rmax

a. r = 0

More _____ need to be studied in order to find out whether interspecific competition strongly influences the species composition and structure of most communities. a. r-selected species b. K-selected species c. prey species d. communities e. predators

a. r-selected species

Three plants that share the same niche have taproots of different length. This is an example of ____. a. resource partitioning b. allopatric speciation c. sympatric speciation d. the competitive exclusion principle e. character displacement

a. resource partitioning

In systemic acquired resistance, the regulatory protein NPR-1 moves from the cytoplasm to the cell nucleus, apparently in response to a buildup of ____ in the cytoplasm. a. salicylic acid b. oligosaccharins c. brassinosteroids d. ethylene e. jasmonates

a. salicylic acid

Self-incompatibility in flowering plants is a biochemical recognition and rejection process that prevents ____. a. self-fertilization but not self-pollination b. self-pollination but not self-fertilization c. self-pollination and occasionally prevents self-fertilization d. self-fertilization and occasionally prevents self-pollination e. both self-fertilization and self-pollination

a. self-fertilization but not self-pollination

Fecundity is ____. a. the average number of offspring produced b. a summary of the demographic characteristics of a population c. the proportion of individuals alive at the start of an interval that die during that interval d. the proportion of individuals alive at the start of an interval that survive to the start of the next interval e. a group of individuals of similar age

a. the average number of offspring produced

Stomata generally close in response to ____. a. the release of abscisic acid by the roots b. a drop in CO2 concentration in leaf air spaces c. exposure to red light d. a drop in O2 concentration in leaf air spaces e. an increase in CO2 concentration in the leaf air spaces

a. the release of abscisic acid by the roots

A researcher using hydroponic methods to determine if molybdenum is an essential plant nutrient would likely ____. a. transfer healthy plants to a solution without molybdenum and observe their growth b. grow seeds in solutions with varying molybdenum concentrations to see which grows best c. add extra molybdenum to a complete nutrient solution to see if plant growth improves d. transfer unhealthy plants to a solution containing molybdenum to see if their growth improves e. grow plants from seed in a molybdenum-deficient environment to see if they grow properly

a. transfer healthy plants to a solution without molybdenum and observe their growth

Ocean acidification is caused by ____. a. transfer of carbon dioxide from the atmosphere to the ocean b. phosphorous fertilizer runoff c. nitrogen fertilizer runoff d. transfer of carbon dioxide from the ocean to the atmosphere e. global warming

a. transfer of carbon dioxide from the atmosphere to the ocean

To conserve nutrients, plants that drop their leaves in autumn _____. a. transport mineral ions from the leaves to the twigs and branches before the leaves fall b. assimilate excess mineral ions into glucose, which is then transported to the roots c. retain mineral ions in the leaves so when they fall, they will attract pollinators to the tree d. transport chlorophyll from the leaves to the twigs and branches before the leaves fall e. convert mineral ions to ATP for winter storage in the bark

a. transport mineral ions from the leaves to the twigs and branches before the leaves fall

Humans have disrupted the nitrogen cycle primarily by ____. a. using nitrogen-containing fertilizers b. leaching c. cutting down forests d. crop rotation e. irrigation

a. using nitrogen-containing fertilizers

The chemical message system that stimulates a plant to develop flowers begins with the expression of the _____ gene. a. vernalization b. FT c. CONSTANS d. AP1 e. CO

a. vernalization

Which weather pattern is characteristic of a La Niña event? a. warm and dry weather in the southern United States b. high ocean surface temperatures c. high pressure over the western Pacific d. ocean surface waters moving from west to east e. air movement from west to east

a. warm and dry weather in the southern United States

Which of the following it the most typical order of events in seed germination? a. water imbibition ® seed coat splits ® root cells divide and elongate ® shoot cells divide and elongate b. water imbibition ® root cells divide and elongate ® seed coat splits ® shoot cells divide and elongate c. seed coat splits ® water imbibition ® root cells divide and elongate ® shoot cells divide and elongate d. seed coat splits ® water imbibition ® shoot cells divide and elongate ® root cells divide and elongate e. shoot cells divide and elongate ® root cells divide and elongate ® seed coat splits ® water imbibition

a. water imbibition ® seed coat splits ® root cells divide and elongate ® shoot cells divide and elongate

Active transport in plant root cells requires that those cells have access to O2. Normally there is enough O2 available in air pockets in the soil, but flooded soil has very little O2. Thus, unless they have special adaptations, plants in flooded soil effectively have no active transport in their roots. Which of the following should you expect to occur for trees without special adaptations to flooding after several days in flooded soil? a. wilting of their leaves b. excess uptake of water and minerals in the xylem, and excess water pushed out at the margins of their leaves c. excess uptake of water and minerals in the xylem only d. bursting of leaf cells due to excess water flow e. excess water pushed out at the margins of their leaves only

a. wilting of their leaves; Wilting is the loss of rigidity of non-woody parts of plants. This occurs when the turgor pressure in non-lignified plant cells falls towards zero, as a result of diminished water in the cells. The rate of loss of water from the plant is greater than the absorption of water in the plant.

In vascular plants, water and dissolved minerals are transported from roots to the stems and leaves by ____. a. xylem b. parenchyma c. collenchyma d. sclerenchyma e. phloem

a. xylem

What is the yP of a living plant cell that has y = -0.2 MPa and yS = -0.4 MPa? a. yP = 0.2 MPa b. yP = -0.2 MPa c. yP = -0.6 MPa d. yP = 0.08 MPa e. yP = 0.5 MPa

a. yP = 0.2 MPa

The monarch butterfly has an undesirable taste and the viceroy butterfly has a selective advantage because it looks like the monarch. This is an example of ____. a. aposematic coloration b. Batesian mimicry c. Müllerian mimicry d. competitive exclusion principle e. cryptic coloration

b. Batesian mimicry

What is the relationship between species richness and recovery from natural disturbances? a. Communities with more diversity experience more natural disturbances. b. Communities with more diversity recover more rapidly from natural disturbances. c. Communities with more diversity recover less rapidly from natural disturbances. d. Communities with more diversity do not recover from natural disturbances. e. There is no correlation between community diversity and recovery from natural disturbances.

b. Communities with more diversity recover more rapidly from natural disturbances.

Why do species with large body sizes typically have lower population densities? a. There are not enough individuals to grow the population. b. Each large organism consumes more available resources. c. Small organisms have more potential mates. d. Large organisms do not like living near one another. e. Genetic diversity is low.

b. Each large organism consumes more available resources.

At night, assuming no artificial lights, primarily ____. a. Pfr absorbs far-red light and is converted to Pr b. Pfr is converted to Pr c. Pfr absorbs red light and is converted to Pr d. Pr absorbs red light and is converted to Pfr e. Pr absorbs far-red light and is converted to Pfr

b. Pfr is converted to Pr

Which characteristic is descriptive of a population experiencing geometric population growth? a. ΔN/Δt is increasing. b. Population doubles in size after each generation. c. Graph of the population growth produces a "J" shaped curve. d. Population increases at an increasing rate. e. Per capita growth rate remains constant.

b. Population doubles in size after each generation.

When an apical meristem cell divides, one daughter cell is called the initial and the other is called the derivative. What are the fates of these cells? a. The initial is used to form primary meristems, and the derivative remains part of the apical meristem. b. The initial remains part of the apical meristem, and the derivative is used to form primary meristems. c. The initial is used to form primary meristems, and the derivative is used to form secondary meristems. d. Both the initial and the derivative remain part of the apical meristem. e. Both the initial and the derivative are used to form primary meristems.

b. The initial remains part of the apical meristem, and the derivative is used to form primary meristems.

Which conclusion can be drawn from Gause's experiments on interspecific competition between two species of Paramecium that are cultured together and feed on the same resource? a. Paramecium populations survive well together because they have no limiting resources. b. When two populations of Paramecium use the same limiting resource, they cannot coexist long term. c. When two populations of Paramecium use the same limiting resource, they can coexist long term. d. Both populations of Paramecium expire due to a build-up of waste products. e. One population of Paramecium used the other as a food source.

b. When two populations of Paramecium use the same limiting resource, they cannot coexist long term.

Stomata generally open in response to ____. a. a drop in O2 concentration in leaf air spaces b. a drop in CO2 concentration in leaf air spaces c. an increase in CO2 concentration in the leaf air spaces d. exposure to red light e. the release of abscisic acid by the roots

b. a drop in CO2 concentration in leaf air spaces

Consider a living plant cell in a living leaf that has a higher water potential than the fluids surrounding the cell. In such a situation there should be ____. a. a net flow of water into the cell b. a net flow of water out of the cell c. gain of water by the cell only if the cell's pressure potential is high enough d. gain of water by the cell only if the cell's pressure potential is low enough e. no net flow of water into or out of the cell

b. a net flow of water out of the cell

Areas that receive heavy rainfall tend to have ____ soils, and arid regions tend to have ____ soils. a. alkaline; acid b. acidic; alkaline c. acidic; pH-neutral d. pH-neutral; alkaline e. pH-neutral; acidic

b. acidic; alkaline

Nitrogen is made available to plants for their use by the process(es) of ____. a. nitrification only b. ammonification, nitrification, and nitrogen fixation c. ammonification only d. ammonification and nitrification only e. nitrogen fixation only

b. ammonification, nitrification, and nitrogen fixation

Statoliths, particles that move in the direction gravity pulls them, are typically ____ in plants. a. calcium carbonate crystals b. amyloplasts c. nuclei d. vacuoles e. hormones

b. amyloplasts

If you want all of the orange trees in your orchard to uniformly flower and set fruit, you should spray ____ on your plants. a. cytokinins b. auxins c. ethylene d. salicylic acid e. brassinosteroids

b. auxins

In flowering plants an ovary is part of a(n) ____. calyx a. calyx b. carpel c. stamen d. corolla e. ovule

b. carpel

Which interaction is advantageous for one species, but has no effect on the other? a. mutualism b. commensalism c. parasitism d. predation e. herbivory

b. commensalism

An ecologist who studies groups of populations that occur together in one area is a(n) ____ ecologist. a. behavioral b. community c. ecosystem d. organismal e. population

b. community

A unique characteristic of plant cells is their ability to ____. a. form defensive compounds b. continuously grow and generate new organs throughout their life cycle c. carry out cellular respiration d. photosynthesize e. protect themselves through movement

b. continuously grow and generate new organs throughout their life cycle

Evidence of the hypersensitive response in plants can be seen as _____. a. formation of galls on leaves or stems b. dead brown spots on leaves c. the presence of heat-shock proteins d. leaf abscission e. the presence of secondary metabolites

b. dead brown spots on leaves

Carrying capacity is ____. a. determined by the individuals of a species b. defined for each population, and varies from one habitat to another c. the same across all populations d. the same across all environments e. the same in one habitat through time

b. defined for each population, and varies from one habitat to another

Studies have determined that ____ is not responsible for the cyclical rise and fall of arctic hare and lynx populations. a. intraspecies competition b. disease c. predation d. a limited food supply for hares e. predation by other mammals

b. disease

Two species utilizing the same food source is an example of ____. a. interference competition b. exploitative competition c. mimicry d. mutualism e. coevolution

b. exploitative competition

A small decrease in seawater pH was shown to have a significant effect on ____. a. climate change b. gene expression in sea urchin larvae c. gene expression in zooplankton d. the oceanic sink for carbon dioxide e. carbon dioxide accumulation in the ocean

b. gene expression in sea urchin larvae

The plant hormone ____ is primarily responsible for helping break the dormancy of seeds and buds. a. ethylene b. gibberellin c. jasmonate d. cytokinin e. auxin

b. gibberellin

An agar block filled with auxin is placed on top of a shoot that has had the shoot tip removed. The agar block is placed so that it covers only one side of the top of the shoot. You would expect the shoot to ____. a. grow straight up b. grow faster on the side with the agar block c. grow faster on both the side away from the agar block and on the side with agar block d. grow faster on the side away from the agar block e. stop growing

b. grow faster on the side with the agar block

A population's ____ is the specific environment in which it lives. a. size b. habitat c. growth rate d. geographical range

b. habitat

Type III survivorship curves reflect ____. a. high survivorship b. high juvenile mortality c. relatively constant mortality d. high adult mortality e. low juvenile mortality

b. high juvenile mortality

When solutes are unloaded from phloem, water ____. a. is pumped into the phloem by active transport b. leaves the phloem by osmosis c. is pumped out of the phloem by active transport d. leaves the xylem by osmosis e. moves into the phloem by facilitated diffusion

b. leaves the phloem by osmosis

Which of the following occurs for the production of a pollen grain from a microspore mother cell? a. mitosis, then meiosis, then mitosis b. meiosis, then mitosis c. meiosis only d. mitosis, then meiosis e. mitosis only

b. meiosis, then mitosis

An increase in air temperature will result in ____ water vapor in the atmosphere because warm air holds ____ water vapor than cold air does. a. less; more b. more; more c. no change in; less d. more; less e. less; less

b. more; more

Respiration affects a compartment model by ____. a. moving carbon, but not oxygen, from the available organic compartment to the available inorganic component b. moving both carbon and oxygen from the available organic compartment to the available inorganic component c. moving oxygen, but not carbon, from the available organic compartment to the available inorganic component d. moving carbon, but not oxygen, from the available inorganic compartment to the available organic component e. moving both carbon and oxygen from the available inorganic compartment to the available organic component

b. moving both carbon and oxygen from the available organic compartment to the available inorganic component

The most common limit to plant growth is a lack of ____. a. oxygen b. nitrogen c. hydrogen d. carbon e. phosphorous

b. nitrogen

What benefit do legumes derive from Rhizobium? a. increase root surface area b. nitrogen fixation c. retain water so it is more available to the plant d. protection from predators e. help make carbon dioxide more available

b. nitrogen fixation

In flowering plants, how many egg cells are typically produced from each megaspore mother cell? a. two b. one c. eight d. four e. three

b. one

Which ecosystem covers a large percentage of Earth's surface and, despite having low productivity, contributes a high percentage of total net primary productivity? a. tropical deciduous forest b. open ocean c. desert and thornwoods d. temperate rainforest e. extreme desert, rock, sand, ice

b. open ocean

Which organisms would most likely have the highest tissue concentration of DDT? a. zooplankton b. osprey c. small herbivorous fish d. large herbivorous fish e. large predatory fish

b. osprey

According to the acid-growth hypothesis, auxin causes increased acidity in cell walls, which then activates ____ that disrupt(s) bonds between cellulose microfibrils, allowing cell expansion. a. an mRNA b. proteins called expansins c. K+ ions d. a membrane potential e. AUX1 transporters

b. proteins called expansins

Leopard seals feed on emperor penguins, which feed on secondary consumers. Which trophic level would the leopard seal occupy in this food web? a. primary consumer b. quaternary consumer c. decomposer d. detritivore e. primary producer

b. quaternary consumer

The uptake of water and mineral ions from the soil occurs primarily at the ____. a. pericycle b. root hairs c. quiescent center d. root cap e. endodermis

b. root hairs

The principal driving force for guttation is ____. a. pumping by the xylem cells b. root pressure c. sunlight d. upward pressure as sugar is forced into the roots e. passive transport

b. root pressure

Rhizomes, tubers, corms, and stolons are examples of modified ____. a. roots b. stems c. bulbs d. leaves e. flowers

b. stems

Sucrose moves into a cell against its concentration gradient at the same time that protons move into the cell along their concentration gradient. This is an example of ____. a. passive diffusion b. symport c. facilitated diffusion d. active transport e. antiport

b. symport

Chemical cues that help guide a developing pollen tube toward an ovule are released by the ____. a. central cell b. synergids c. egg d. sperm e. antipodal cells

b. synergids

The growth-promoting substance that promotes stem elongation and bending toward light is produced primarily in ____. a. root tips, traveling to the stem in the xylem b. the shoot tip c. the center of the stem region where elongation or bending occurs d. flowers and flower buds e. root tips, traveling to the stem in the phloem

b. the shoot tip

Cool, dry air descends at which latitude? a. 45o N and S b. both 30o and 60o N and S c. 30o N and S d. at the poles e. the equator

c. 30o N and S

Most deserts occur near ____ latitude because of the presence of dry descending air masses. a. 20º b. 0º c. 30º d. 40º e. 10º

c. 30º

The addition of excess phosphorus causes lakes to become eutrophic because the nutrients trigger blooms of photosynthetic cyanobacteria. Why do these blooms cause low oxygen levels in lakes? a. Cyanobacteria use up more oxygen than they produce. b. Cyanobacterial blooms only occur in waters naturally low in oxygen. c. Cyanobacteria are net producers of oxygen while alive, but when they die aerobic bacteria use oxygen while decomposing them. d. Excess phosphorus binds to dissolved oxygen in the water. e. Cyanobacteria are aerobic heterotrophs, consuming oxygen and producing carbon dioxide.

c. Cyanobacteria are net producers of oxygen while alive, but when they die aerobic bacteria use oxygen while decomposing them.

Which consequence is a documented result of global warming? a. Animals display later migration and breeding. b. Minimum temperatures at Yosemite have decreased about 3o over the last century. c. Minimum temperatures at Yosemite have increased about 3o over the last century. d. Plants display later flowering and growth. e. Cold-adapted species are more common.

c. Minimum temperatures at Yosemite have increased about 3o over the last century.

Which characteristic is not true for an essential element? a. It may be required in only trace amounts. b. It may be contained in plant seeds in high enough quantities to sustain the adult plant. c. Occasionally, it can be functionally replaced by another element. d. It is necessary for normal growth and reproduction. e. It may play only one role in plant metabolism.

c. Occasionally, it can be functionally replaced by another element.

What are the specific environmental consequences of a phytoplankton bloom? a. An increase in phytoplankton acidifies ocean water. b. Phytoplankton are decomposed by anaerobic bacteria which enriches the surrounding water with oxygen. c. Phytoplankton are decomposed by aerobic bacteria, which depletes the surrounding water of oxygen. d. Phytoplankton use up hydrogen ions, which decreases the acidity of the surrounding water. e. Phytoplankton fix nitrogen in the water causing nitrification.

c. Phytoplankton are decomposed by aerobic bacteria, which depletes the surrounding water of oxygen.

What is the relationship between age-specific mortality and age-specific survivorship? a. Age-specific survivorship is the proportion of individuals alive at the start of an age interval that die during the age interval; age-specific mortality is the proportion that survive until the start of the next interval. b. Age-specific mortality is always less than age-specific survivorship. c. The sum of age-specific mortality and age-specific survivorship always equals 1. d. Age-specific survivorship is always greater than 1. e. Age-specific mortality is the proportion of individuals alive at the start of an age interval; age-specific survivorship is the proportion that die before the start of the next interval.

c. The sum of age-specific mortality and age-specific survivorship always equals 1.

Animals trapped and digested by "carnivorous" plants such as the cobra lily are used primarily as ____. a. a carbon source for the plant b. an energy supplement for small plants growing in shady areas c. a nutrient supplement in nutrient-deficient environments d. food for bacteria and fungi that grow symbiotically with the plant roots e. an energy supplement during winter months

c. a nutrient supplement in nutrient-deficient environments

In herbaceous plants, the stress-related closing of stomata is regulated by ____. a. O2 concentration b. sunlight c. abscisic acid d. ion concentrations in the xylem e. CO2 concentration

c. abscisic acid

Geographically, where is net primary productivity the highest? a. at the south pole b. at the north pole c. at the equator d. in the Northern hemisphere e. between 30o and 60o

c. at the equator

Sedimentation converts ions and particles from the ____ into rocks of the ____. a. unavailable inorganic compartment; unavailable organic compartment b. available inorganic compartment; unavailable organic compartment c. available inorganic compartment; unavailable inorganic compartment d. available organic compartment; unavailable inorganic compartment e. available inorganic compartment; available organic compartment

c. available inorganic compartment; unavailable inorganic compartment

Aquaporins are ____. a. carrier proteins for water b. channel proteins for solutes c. channel proteins for water d. carrier proteins for water and solutes e. carrier proteins for solutes

c. channel proteins for water

Which factor has little effect on the rate of transpiration? a. the amount of direct solar radiation b. air movement c. daily fluctuations in atmospheric carbon dioxide concentrations d. air temperature e. relative humidity

c. daily fluctuations in atmospheric carbon dioxide concentrations

The innermost layer of the root cortex, known as the ____, is a selectively permeable barrier that helps control the movement of water and dissolved minerals. a. quiescent center b. root cap c. endodermis d. pericycle e. root hairs

c. endodermis

The range of conditions and resources required by a population is known as its ____, while the range of conditions and resources that it actually uses is known as its ____. a. realized niche; fundamental niche b. fundamental niche; habitat c. fundamental niche; realized niche d. ecological niche; trophic level e. trophic level; habitat

c. fundamental niche; realized niche

Hydroponic culture is the process of ____. a. growing plants with specific hydrocarbons added to the soil to test the effect on plant growth b. irrigation of dry areas to improve mineral absorption by plants c. growing plants in pure water mixed with carefully measured amounts of specific minerals d. growing plants in ponds and lakes to improve their access to water, allowing the plants to place more resources into the shoot system e. irrigation of dry areas to prevent crop plants from wilting

c. growing plants in pure water mixed with carefully measured amounts of specific minerals

Water particles adhere tightly to soil particles due to _____. a. the small spaces between particles through which gravity can draw the water b. adhesive properties of minerals in the soil c. hydrogen bonding with negative charges on soil particles d. ionic bonding with negative charges on soil particles e. hydrogen bonding with positive charges on soil particles

c. hydrogen bonding with negative charges on soil particles

Climate change leads to ____, which releases additional carbon dioxide into the atmosphere. a. increased severity of volcanic eruptions b. sea level reductions c. increased frequency and severity of forest fires d. increased logging e. increased size of polar ice caps

c. increased frequency and severity of forest fires

Stomata open when K+ concentration in guard cells ____, followed by water ____ the guard cells by osmosis. a. increases; leaving b. decreases; leaving c. increases; entering d. decreases; entering e. increases H+; leaving

c. increases; entering

The synthesis of ____ is triggered when cells bind systemin. a. cytokinin b. gibberellin c. jasmonate d. auxin e. brassinosteroids

c. jasmonate

Suppose a living plant cell has yP = 0.4 MPa and yS = -0.5 MPa. If the plant cell is placed into a beaker filled with a solution with y = yS = -0.9 MPa, then the cell should ____. a. take up water until its y = yS of the solution b. lose water until its yS = its yP c. lose water until its y = y of the solution d. take up water until within the cell yP = -yS e. take up water until it bursts

c. lose water until its y = y of the solution

A mutant soybean plant that is unable to produce leghemoglobin will most likely suffer from ____ deficiency. a. magnesium b. phosphorus c. nitrogen d. potassium e. oxygen

c. nitrogen

Compared to other regions, day length is ____ and sunlight intensity is ____ near the equator. a. least variable; weakest b. more variable; strongest c. more variable; weakest d. least variable; strongest e. least variable; constant

d. least variable; strongest

You might infer from packages of commercial fertilizer that which nutrients are most limiting to plant growth? a. iron, magnesium, and nitrogen b. hydrogen, phosphorus, and magnesium c. nitrogen, phosphorous, and potassium d. carbon, nitrogen, and phosphorous e. phosphorus, potassium, and calcium

c. nitrogen, phosphorous, and potassium

What is thought to be responsible for the worldwide deaths of corals and their endosymbiotic algae? a. soil runoff b. declining primary productivity c. ocean acidification d. depletion of oxygen in the oceans e. nitrogen fixation

c. ocean acidification

Some studies suggest that, as global warming progresses, tropical lowland trees may be limited in their ability to move northward because of ____. a. extreme weather events like hurricanes and blizzards b. development and habitat loss c. predicted desertification of temperate areas d. flooding of coastal areas e. temperatures in the north still being too low

c. predicted desertification of temperate areas

Which tissue gives rise to primary vascular tissues? a. ground meristem b. apical meristem c. procambium d. protoderm e. vascular cambium

c. procambium

In some cases, when an insect begins feeding on a leaf the plant responds by activating a signaling pathway that results in the production of ____, which disrupt an insect's capacity to digest proteins. a. cytokinins b. chitinases c. protease inhibitors d. lipases e. gibberellins

c. protease inhibitors

The root apical meristem is surrounded and protected by a structure called the ____. a. quiescent center b. pericycle c. root cap d. root hairs e. endodermis

c. root cap- covers the apical meristem and protects it from damage

Sea otter populations were reduced by overhunting, allowing an overgrowth of one of their prey animals, the ____, which subsequently consumed and decimated ____populations. a. crab; kelp b. harbor seals; fish c. sea urchin; kelp d. abalone; algae e. crabs; shrimp

c. sea urchin; kelp

The movement of NH4+ ions into a cell down an electrochemical gradient created by H+ pumping is an example of ____. a. an ion pump b. passive diffusion c. secondary active transport d. passive transport e. facilitated diffusion

c. secondary active transport

In a living plant cell in a living plant, you would expect the cytoplasm to be ____. a. slightly more positively charged than the fluid outside the cell b. essentially the same charge as the fluid outside the cell c. slightly more negatively charged than the fluid outside the cell d. much more negatively charged than the fluid outside the cell e. much more positively charged than the fluid outside the cell

c. slightly more negatively charged than the fluid outside the cell

Girdling is the process by which bark is removed from the entire circumference of a tree or branch. This is lethal to a tree because it prevents ____. a. water uptake b. respiration c. sugar transport to roots d. photosynthesis e. water transport to leaves

c. sugar transport to roots

In the equation ΔN/Δt = B - D , B represents ____. a. time period b. change in population size c. total births d. change in population size over time e. total deaths

c. total births

The thermocline prevents ____ the top layer of the limnetic zone and the deep profundal zone. a. detritus formation in b. plankton growth in c. vertical mixing between d. photosynthesis in e. autumn overturn in

c. vertical mixing between

According to the cohesion-tension mechanism of water transport, cohesion occurs because ____. a. water is pushed into the xylem by bulk flow b. water is pushed into the xylem by phloem pressure c. water molecules tend to form hydrogen bonds with each other d. waxy coatings on insides of xylem keep water molecules together in the xylem e. evaporation removes water from the leaves Hide

c. water molecules tend to form hydrogen bonds with each other

Suppose two living plant cells are in contact with each other so that water, but not solutes, can pass between them. The cells have the same water potential. One cell has yP = 0.3 MPa and yS = -0.5 MPa, while the other cell has yS = -0.3 MPa. What is the yP of the second cell? a. yP = 0.5 MPa b. yP = 0.8 MPa c. yP = 0.1 MPa d. yP = -0.8 MPa e. yP = 0 MPa

c. yP = 0.1 MPa

After fertilization in flowering plants, an embryo in a seed ____. a. is usually a gametophyte but can be a sporophyte b. is always a gametophyte c. begins as a gametophyte and ends up as a sporophyte before germination d. is always a sporophyte e. begins as a sporophyte and ends up as a gametophyte before germination

d. is always a sporophyte

The overall ecological efficiency of most organisms is between ____ percent. a. 2 and 5 b. 10 and 50 c. 50 and 75 d. 5 and 20 e. 1 and 2

d. 5 and 20

Conservation efforts using ____ are being used to protect the critically endangered Florida panther by allowing the animals to move safely between fragmented conservation areas. a. ecotourism b. population viability analyses c. beta-diversity d. landscape corridors e. introduction of nonnative prey species

d. landscape corridors

A group of neighboring populations that exchange individuals is defined as a ____. a. sink population b. megapopulation c. community d. metapopulation e. source population

d. metapopulation

How does habitat fragmentation affect biodiversity? a. Habitat fragmentation connects terrestrial and aquatic habitats. b. As long as the fragments are of good quality habitat, biodiversity will not be affected. c. Habitat fragmentation increases biodiversity because adaptation to local conditions stimulates evolution. d. Habitat fragmentation is a threat to biodiversity because small habitat patches sustain only small populations. e. Habitat fragmentation increases biodiversity because it reduces entry of exotic species.

d. Habitat fragmentation is a threat to biodiversity because small habitat patches sustain only small populations.

How can predators influence the species richness and structure of communities? a. Predators increase the carrying capacity of their prey. b. Predators increase the population sizes of pathogens. c. Predators increase the population sizes of their prey. d. Predators reduce the population sizes of their prey. e. Predators destabilize competitive interactions among their prey.

d. Predators reduce the population sizes of their prey.

A biome is most specifically defined as ____. a. a biological community and the physical environment with which it interacts b. an assemblage of species living in the same place c. the total dry weight of plants present in a specific area at any given time d. a vegetation type plus its associated microorganisms, fungi, and animals e. a group of organisms of the same species living together at one time

d. a vegetation type plus its associated microorganisms, fungi, and animals

Greenhouse gases ____, which is directed back toward Earth, maintaining the temperature of the atmosphere. a. emit carbon dioxide b. emit heat energy c. absorb carbon dioxide d. absorb heat energy e. absorb solar energy

d. absorb heat energy

Loading of most carbohydrates produced by photosynthesis into companion cells at a source occurs by ____. a. diffusion of water from the xylem b. suction from unloading at a sink c. osmosis d. active transport e. proton pumping

d. active transport

Stomata close when ____ guard cells and they become ____. a. active transport pumps H+ out of; turgid b. active transport of H+ stops in; turgid c. active transport pumps H+ into; flaccid d. active transport of H+ stops in; flaccid e. active transport pumps H+ into; turgid

d. active transport of H+ stops in; flaccid

The Casparian strip of the endodermis stops water from the ____ before it reaches the stele. a. transmembrane pathway only b. symplastic pathway only c. transmembrane and symplastic pathways d. apoplastic pathway only e. apoplastic, transmembrane, and symplastic pathways

d. apoplastic pathway only

In herbaceous plants, the stress via the ____. a. transmembrane pathway only b. transmembrane and symplastic pathways c. symplastic pathway only d. apoplastic, transmembrane, and symplastic pathways e. apoplastic pathway only

d. apoplastic, transmembrane, and symplastic pathways

In the equation ΔN/Δt = B - D , expressing deaths and births as per capita rates allows ecologists to _____. a. model geometric growth b. accurately measure deaths c. find the population growth rate d. apply the model to a population of any size e. accurately measure births

d. apply the model to a population of any size

What is the main cause of carbon dioxide build-up in the atmosphere? a. deforestation b. respiration due to overpopulation c. flooding d. burning fossil fuels e. droughts

d. burning fossil fuels

Once a pollen tube lands on a compatible stigma ____. a. other pollen tubes can penetrate that ovule more easily b. the flower dies to prevent further pollination c. that pollen tube continues on to another ovule d. chemical cues guide the pollen tube from the stigma to the embryo sac of an ovule e. other pollen tubes are attracted to that ovule

d. chemical cues guide the pollen tube from the stigma to the embryo sac of an ovule

Which population dispersion is the most common in nature? a. random b. dynamic c. uniform d. clumped e. unpredictable

d. clumped

A(n) ____ provides nutrients in germinating seedlings of eudicots. a. hypocotyl b. endosperm c. suspensor d. cotyledon e. epicotyl

d. cotyledon

Which factor disrupts the life histories of aquatic species? a. reduced connectivity in river systems b. increased sedimentation c. introduction of nonnative species d. disruption of river flow patterns e. low river volume

d. disruption of river flow patterns

A rain shadow is created when ____. a. wind direction reverses seasonally b. cool air descends and replaces warm air over land through onshore flow c. cool air descends and replaces warm air over the sea through offshore flow d. dry air on the windward side rises and absorbs water on the leeward side, such that the leeward side remains dry e. mountains force air to sink and absorb water on the windward side, causing the leeward side of the mountains to receive excessive rainfall

d. dry air on the windward side rises and absorbs water on the leeward side, such that the leeward side remains dry

In flowering plants, how many sperm cells are typically produced from each microspore mother cell? a. four b. one c. three d. eight e. two

d. eight

The plant hormone that triggers abscission of leaves in the fall is _____. a. jasmonate b. abscisic acid c. a brassinosteroid d. ethylene e. a phytochrome

d. ethylene

Meiosis in flowering plants gives rise to cells that are ____. a. diploid sporophytes b. diploid gametophytes c. haploid sporophytes d. haploid gametophytes e. sporophytes that can be haploid or diploid

d. haploid gametophytes

Burning fossil fuels has clearly resulted in ____. a. increases in carbon retention in animals b. decreases in atmospheric concentrations of oxygen c. increases in concentrations of carbon dioxide in soils d. increases in atmospheric concentrations of carbon dioxide e. increases in extinction rates

d. increases in atmospheric concentrations of carbon dioxide

An alternative to species-based conservation focuses on the preservation of ____. a. large species b. small species c. insect species only d. intact habitats e. plant species only

d. intact habitats

Most plants absorb nitrogen mainly in the form of _____. a. ammonia b. ammonium c. nitrogen gas d. nitrate e. nitrite

d. nitrate

The surfaces of clay particles in soil ____. a. acidify the soil b. often bear positively charged ions c. release water to plants easily d. often bear negatively charged ions e. are generally hydrophobic

d. often bear negatively charged ions

An insect lays eggs inside another organism and the young consume the tissues of the living host. This is an example of a(n)____. a. fundamental niche b. carnivore c. mutualist d. parasitoid e. parasite

d. parasitoid

A flower with carpels and stamens but no petals or sepals is ____. a. imperfect and complete b. perfect and complete c. sterile d. perfect and incomplete e. imperfect and incomplete

d. perfect and incomplete

Starting from the outside and moving in toward the center, which list gives the correct order of tissues in the stem of a young tree? a. primary xylem, secondary xylem, secondary phloem, primary phloem b. primary phloem, secondary xylem, secondary phloem, primary xylem c. secondary phloem, primary phloem, primary xylem, secondary xylem d. primary phloem, secondary phloem, secondary xylem, primary xylem e. secondary phloem, primary xylem, secondary xylem, primary phloem

d. primary phloem, secondary phloem, secondary xylem, primary xylem

Net primary productivity is a measure of the rate at which ____ accumulate energy, as well as the rate at which new ____ is added to a system. a. consumers; inorganic material b. consumers; biomass c. carnivores; prey d. producers; biomass e. producers; inorganic material

d. producers; biomass

Jasmonates help plants defend against herbivores because they induce _____. a. increased production of indigestible fibers in leaves b. production of thorns or spines c. production of chemicals that attack an herbivorous insect's nervous system d. production of chemicals that prevent insects from digesting the plant material e. rapid growth to replace leaves removed by herbivores

d. production of chemicals that prevent insects from digesting the plant material

Populations in which environmental conditions don't vary much within a habitat tend to have ____ dispersion. a. uniform b. clumped c. unpredictable d. random e. dynamic

d. random

Expanding air masses ____. a. experience no change b. can hold less water c. sink d. rise e. are cool and dry

d. rise

Wood is composed of ____. a. primary xylem b. secondary phloem c. primary phloem d. secondary xylem e. both xylem and phloem

d. secondary xylem

Which molecule dissolves in water vapor and falls as acid precipitation? a. mercury b. carbonic acid c. sulfuric acid d. sulfur dioxide e. ozone

d. sulfur dioxide

Most mineral ions that plants need are moved into the ____. a. transmembrane pathway via bulk flow b. symplast via facilitated diffusion c. apoplast via facilitated diffusion d. symplast via active transport e. apoplast via bulk flow

d. symplast via active transport

After a plant has survived a microbial invasion, the rest of the plant is often less vulnerable to future infections. This is called ____. a. wound defense b. gene-for-gene recognition c. hypersensitive response d. systemic acquired resistance e. jasmonate response

d. systemic acquired resistance

If nitrifying bacteria were not present in a soil, plants would ____. a. take up nitrogen for their use mainly as NH3 b. take up nitrogen for their use mainly as N2 c. not survive because they could not get useful nitrogen d. take up nitrogen for their use mainly as NH4+ e. take up nitrogen for their use mainly as NO3-

d. take up nitrogen for their use mainly as NH4+

The loss of water vapor from aboveground plant parts is called ____. a. evaporation b. sublimation c. passive transport d. transpiration e. root pressure

d. transpiration

Which environment would be most likely to harbor a biodiversity hotspot? a. savanna b. temperate deciduous forest c. temperate grassland d. tropical island e. desert

d. tropical island

What is the main determinant of biome distribution? a. climate b. vegetation type c. elevation d. weather e. ocean currents

d. weather

In response to increased carbon dioxide levels in the atmosphere over the past 200 years, stomata in leaves of some species have ____. a. increased in number b. declined in number c. become smaller d. become larger e. disappeared

declined in number

What is the significance of genetic variation? a. It influences population interactions. b. It is the raw material for sexual reproduction. c. It is the most fundamental level of species classification. d. It interacts within the biosphere. e. It is the raw material for adaptation, speciation, and evolution.

e. It is the raw material for adaptation, speciation, and evolution

Which forms of nitrogen are readily usable by plants? a. N2 and NH3 b. NO3 - and NO4 - c. NH4 and NH3 d. NH4+ and NO2 - e. NH3, NH4+, and NO3 -

e. NH3, NH4+, and NO3 -

An example from the text contrasts two forests, each with 10 species and a total of 50 trees. In the first forest, 39 of the 50 trees represent the dominant species. The second forest has 5 of each of the 10 different species. What conclusion can be drawn regarding these two forests? a. The amount of animal species in each forest would be the same. b. The first forest must have had some human interference. c. The second forest must have had some human interference. d. The first forest is more diverse than the second. e. The second forest is more diverse than the first.

e. The second forest is more diverse than the first

The plant hormone ____ triggers plant responses to environmental stresses such as cold snaps, high salinity, and drought. a. jasmonate b. cytokinin c. oligosaccharin d. ethylene e. abscisic acid

e. abscisic acid

All environments have both ____ and ____ components. a. lithospheric; atmospheric b. ecologic; atmospheric c. hydrospheric; lithospheric d. organismal; ecologic e. biotic; abiotic

e. biotic; abiotic

Leaf chlorosis is not likely to be caused by a deficiency in ____. a. nitrogen b. zinc c. magnesium d. iron e. boron

e. boron

The plant hormone structurally similar to adenine is ____. a. brassinosteroid b. ethylene c. abscisic acid d. systemin e. cytokinin

e. cytokinin

Which factor is responsible for reductions in population size? a. dispersion b. immigration c. reproduction d. birth e. death

e. death

A plant species where each plant can only make either male or female flowers is called a ____ species and always has ____ flowers. a. dioecious; complete b. monoecious; complete c. monoecious; perfect d. monoecious; imperfect e. dioecious; imperfect

e. dioecious; imperfect

Conservation through restoration involves ____. a. limited livestock grazing b. some human residents and livestock grazing c. people allowed only as temporary visitors d. completely excluding people e. efforts to remove contaminants and other unnatural obstructions

e. efforts to remove contaminants and other unnatural obstructions

A time lag in the response of survivorship and fecundity to a population's density can occur because ____ is usually determined by the availability of resources at some time in the past. a. competition b. population growth c. death d. immigration e. fecundity

e. fecundity

The onset of the growth of a plant embryo, termed ____, starts when the seed begins to soak up water. a. hatching b. gestation c. splitting d. imbibition e. germination

e. germination

The hormones _____ are probably involved in breaking dormancy. a. ethylene and gibberellins b. jasmonates and abscisic acid c. brassinosteroids and jasmonates d. ethylene and brassinosteroids e. gibberellins and abscisic acid

e. gibberellins and abscisic acid

Unlike in animal meiosis, meiosis in plants gives rise to ____. a. haploid gametes b. cells without walls c. diploid gametes d. diploid spores e. haploid spores

e. haploid spores

What is the main factor contributing to the current human-caused mass extinction? a. the industrial revolution b. decreased population growth c. burning of fossil fuels d. global-warming e. increased population growth

e. increased population growth

A population's ____ occurs under ideal, unrealistic conditions. a. geometric population curve b. per capita growth rate c. per capita population curve d. exponential population curve e. intrinsic rate of increase

e. intrinsic rate of increase

How much energy is ultimately converted into chemical energy by photosynthesis? a. 5% b. 1-2% c. 10% d. 20% e. less than 1%

e. less than 1%

At a source the phloem typically has a water potential that is ____ that in surrounding xylem. a. higher than b. less negative than c. about the same as d. exactly the same as e. lower than

e. lower than

The ____ is self-perpetuating embryonic tissue typically found at the tips of shoots and roots. a. ground tissue b. protoderm c. dermal tissue d. vascular tissue e. meristem

e. meristem

A DNA barcode is being developed for use in conservation biology based on ____. a. chloroplast genes in plants b. mitochondrial genes in plants c. nuclear genes in animals d. bacterial genes e. mitochondrial genes in animals

e. mitochondrial genes in animals

Photosynthetic organisms are essential for limiting the damage done by global warming because they ____. a. move carbon from the soil to the atmosphere b. sequester carbon in geologic sediments c. produce oxygen d. move carbon from the atmosphere to the soil e. move carbon from the atmosphere to living organisms

e. move carbon from the atmosphere to living organisms

For a typical flowering plant, the first cell of the triploid (3n) endosperm is formed from ____. a. one sperm fused with two antipodal cells b. two sperm fused with the egg c. one sperm fused with the synergid d. two sperm fused with a synergid e. one sperm fused with the endosperm mother cell

e. one sperm fused with the endosperm mother cell

A population of mostly ____ individuals with a ____ generation time and a ____ proportion of females is expected to show the most growth in the future. a. reproductive; short; low b. prereproductive; short; low c. postreproductive; long; low d. reproductive; long; low e. prereproductive; short; high

e. prereproductive; short; high

When a plant has a hypersensitive response, production of ____ triggers effects such as the expression of PR proteins. a. oligosaccharins b. ethylene c. cytokinin d. brassinosteroids e. salicylic acid

e. salicylic acid

The main form in which sugars are transported in the phloem sap is ____. a. fructose b. lactose c. glucose d. starch e. sucrose

e. sucrose

In the Northern Hemisphere, seasonal variation in temperatures is caused mainly by ____. a. seasonal variation of energy output from the sun b. uneven warming of the ocean's surface water c. warm equatorial air masses rising and spreading north and south d. the Earth's elliptical orbit taking it closer to and farther away from the sun e. the Earth's tilt on its axis of 23.5º

e. the Earth's tilt on its axis of 23.5º

Biological magnification is best defined as ____. a. the increase in toxicity of a chemical compound resulting from its metabolism by a living organism b. the concentration of degradable poisons within organisms at lower trophic levels c. the declining relative proportion of nondegradable poisons in organisms at higher trophic levels as compared to those at lower trophic levels d. the higher relative proportion of biomass among producers as compared to consumers in an ecosystem e. the concentration of nondegradable poisons within organisms at higher trophic levels

e. the concentration of nondegradable poisons within organisms at higher trophic levels

Which marine zone supports kelp forests? a. the benthic province b. the pelagic province c. the abyssal zone d. the intertidal zone e. the neritic zone

e. the neritic zone

Populations in which individuals repel each other because resources are in short supply tend to have ____ dispersion. a. random b. dynamic c. unpredictable d. clumped e. uniform

e. uniform

Which tissue gives rise to secondary xylem and phloem? a. apical meristem b. ground meristem c. procambium d. protoderm e. vascular cambium

e. vascular cambium

Taxol, a drug treatment for breast and ovarian cancer, was isolated from ____. a. roots of a tree b. insects c. primates d. frog skin e. vascular cambium of a tree

e. vascular cambium of a tree

In a lotic system ____. a. water stands in an open basin b. there is no border between freshwater and terrestrial systems c. marshes predominate d. freshwater and marine systems intermix e. water flows through channels

e. water flows through channels

Apical dominance is maintained by ____. a. water transported from the roots b. hormones released by the lateral buds c. hormones released by the terminal bud d. sugars produced in the lateral buds e. sugars produced in the leaves

hormones released by the terminal bud