1) What soil composition would be best for availability of nutrients, water, and root development?
- A) equal amounts of sand, clay, and humus
- B) higher proportion of humus; lower amounts of clay and sand
- C) higher proportion of clay; lower amounts of humus and sand
- D) higher proportion of sand; lower amount of humus and clay 1)
What soil composition would be best for availability of nutrients,
water, and root development?
- A) equal amounts of sand, clay, and humus
- B) higher proportion of humus; lower amounts of clay and sand
- C) higher proportion of clay; lower amounts of humus and sand
- D) higher proportion of sand; lower amount of humus and clay
b
2) The highest amount of oxygen will be found in soils containing large amounts of ________.
- A) clay
- B) sand
- C) gravel
- D) silt
c
3) A group of ten tomato plants are germinated and maintained in a large tray with no drainage. After several weeks they all begin to wilt and die despite repeated watering and fertilization. The most likely cause of this die-off is ________.
- A) competition for resources
- B) a lack of oxygen for the roots
- C) organic nutrient depletion
- D) no room left for root growth
b
4) There are several properties that are characteristic of a soil in which typical plants would grow well. Of the following, which would be the least conducive to plant growth?
- A) abundant humus
- B) numerous soil organisms
- C) compacted soil
- D) high cation exchange capacity
c
5) Which of the following soil minerals is most likely leached away during a hard rain?
- A) Na+
- B) K+
- C) Ca++
- D) NO3-
d
6) Which of the following are problems associated with intensive irrigation?
- I) mineral runoff
- II) over fertilization
III) aquifer depletion
- IV) soil salinization
- A) only I and II
- B) only I, III, and IV
- C) only III and IV
- D) I, II, III, and IV
b
7) A young farmer purchases some land in a relatively arid area and is interested in earning a reasonable profit for many years. Which of the following strategies would best allow the farmer to achieve such a goal?
- A) establishing an extensive irrigation system
- B) using plenty of the best fertilizers
- C) finding a way to sell all parts of crop plants
- D) selecting crops adapted to arid areas
d
8) The NPK percentages on a package of fertilizer refer to the ________.
- A) percentages of manure collected from different types of animals
- B) relative percentages of organic and inorganic nutrients in the fertilizer
- C) percentages of three important mineral nutrients
- D) proportions of three different nitrogen sources
c
9) Which of the following would inhibit the growth of most plants?
- A) abundant humus
- B) air spaces
- C) good drainage
- D) a pH above 10.0
d
10) The B horizon of soil has ________.
- A) living organisms and decaying organic matter
- B) a mixture of broken soil with a variety of texture
- C) much less organic matter than the A horizon
- D) partially broken-down rock
c
11) Roots acidify the soil solution by releasing ________ and pumping ________ into the soil.
- A) CO2; K+
- B) CO2; H+
- C) CO2; Na+
- D) N; Na+
b
12) Soil pH is an important factor that influences ________.
- A) cation exchange
- B) the chemical form of minerals
- C) availability of minerals
- D) cation exchange and the chemical form of minerals
d
13) Soil erosion could be controlled by ________.
- A) planting rows of trees as windbreaks
- B) no-till agriculture
- C) terrace hillside crops
- D) all of the above
d
14) Which of the following would be the most effective strategy to remove toxic heavy metals from a soil?
- A) heavy irrigation to leach out the heavy metals
- B) application of sulfur to lower the soil pH and precipitate the heavy metals
- C) adding plant species that have the ability to take up and accumulate heavy metals
- D) inoculating soil with mycorrhizae to avoid heavy-metal uptake
c
15) How would you expect the root system of a plant grown by hydroponics to compare to the root system of a plant grown in soil? The root system of a plant grown by hydroponics would be ________.
- A) more developed
- B) less developed
- C) about the same
- D) absent
b
16) Deficiency of calcium in plants causes ________.
- A) wilting and poor growth
- B) chlorosis between veins and wilting
- C) crinkling of young leaves and death of terminal buds
- D) reduced internode length and crinkled leaves
c
17) Which one of the following elements plays a critical role in the formation of chlorophyll?
- A) magnesium
- B) manganese
- C) calcium
- D) zinc
a
18) Which of the following experiments is the best way to determine if an element is essential for plant growth?
- A) Measure the amount of the element stored in plant tissues.
- B) Measure the amount of the element in the soil after plant growth.
- C) Measure the weight of the plant and soil before and after plant growth.
- D) Grow a plant using hydroponics with and without the element.
d
19) Which criteria allow biologists to divide chemicals into macronutrients and micronutrients?
- A) molecular weight of the element or compound
- B) the quantities of each required by plants
- C) how they are used in metabolism
- D) whether or not they are essential for plant growth
b
20) Which elements are most often the limiting nutrients for plant growth?
- A) nitrogen, potassium, phosphorus
- B) nitrogen, oxygen, hydrogen
- C) carbon, sodium, chlorine
- D) carbon, nitrogen, oxygen
a
21) Synthesis of which of the following compounds in a mature leaf would be least impacted by a temporary soil nitrogen deficiency?
- A) DNA
- B) RNA
- C) amino acids
- D) cellulose
d
22) A major function of magnesium in plants is to be ________.
- A) required to regenerate phosphoenolpyruvate in C4and CAM plants
- B) a component of DNA and RNA
- C) a component of chlorophyll
- D) active in amino acid formation
c
23) Micronutrients are needed in very small amounts because ________.
- A) most of them are mobile in the plant
- B) most serve mainly as cofactors of enzymes
- C) they play only a minor role in the growth and health of the plant
- D) only the most actively growing regions of the plants require micronutrients
b
24) Two groups of tomatoes were grown under laboratory conditions, one with humus added to the soil, and one a control without humus. The leaves of the plants grown without humus were yellowish (less green) compared with those of the plants grown in the humus-enriched soil. The best explanation for this difference is that ________.
c
25) Soil leaching can cause nutrient deficiencies in the soil. Which of the following are symptoms of nutrient deficiency in plants?
- I) chlorosis
- II) death of meristems
III) excess storage of chlorophyll
- IV) small internodes
- A) I, II, and III
- B) II, III, and IV
- C) I, II, and IV
- D) I, II, III, and IV
c
26) If an African violet has chlorosis, which of the following elements might be a useful addition to the soil?
- A) molybdenum
- B) copper
- C) iodine
- D) magnesium
d
27) Which one of the following micronutrients plays a critical role as a component of chlorophyll?
- A) nickel
- B) iron
- C) magnesium
- D) molybdenum
c
28) Nitrogen-fixing bacteria and nitrifying bacteria convert atmospheric nitrogen into different compounds of nitrogen such as: (a) ammonium ion, (b) ammonia, (c) nitrate ion, and (d) nitrite ion. Which of the following is the correct sequence of formation of the nitrogen compounds?
- A) a, b, c, and d
- B) b, a, d, and c
- C) b, a, c, and d
- D) a, b, d, and c
b
29) Which of the following plants is classified as an epiphyte?
- A) Venus flytrap
- B) pitcher plant
- C) staghorn fern
- D) mistletoe
c
30) Nitrogen fixation is a process that ________.
- A) recycles nitrogen compounds from dead and decaying materials
- B) converts ammonia to ammonium
- C) releases nitrate from the rock substrate
- D) converts nitrogen gas into ammonia
d
31) Why is nitrogen fixation an essential process?
- A) Nitrogen fixation can only be done by certain prokaryotes.
- B) Fixed nitrogen is often the limiting factor in plant growth.
- C) Nitrogen fixation is very expensive in terms of metabolic energy.
- D) Nitrogen fixers are sometimes symbiotic with legumes.
b
32) You are weeding your garden when you accidentally expose some roots of your pea plants. You notice swellings (root nodules) on the roots, and there is a reddish tinge to the ones you accidentally damaged. Most likely your pea plants ________.
- A) suffer from a mineral deficiency
- B) are infected with a parasite
- C) are benefiting from a mutualistic bacterium
- D) are developing offshoots from the root
c
33) The specific relationship between a legume and its mutualistic Rhizobium strain probably depends on ________.
- A) each legume having a chemical dialogue with a fungus
- B) each Rhizobium strain having a form of nitrogenase that works only in the appropriate legume host
- C) each legume being found where the soil has only the Rhizobium specific to that legume
- D) specific recognition between the chemical signals and signal receptors of the Rhizobium strain and legume species
d
34) Rhizobia, actinomycetes, and cyanobacteria all share the common feature that they can ________.
- A) increase water uptake in plants
- B) kill parasites in the soil
- C) exist in extreme environments
- D) fix atmospheric nitrogen
d
35) The earliest vascular plants on land had underground stems (rhizomes), but no roots. Water and mineral nutrients were most likely obtained by ________.
- A) diffusion through stomata
- B) absorption by mycorrhizae
- C) osmosis through the root hairs
- D) diffusion across the cuticle of the rhizome
b
36) What major benefits do plants and mycorrhizal fungi receive from their symbiotic relationship?
- A) Plants receive enzymes, and fungi receive nitrogen and phosphorus.
- B) Plants receive increased root surface area, and fungi receive digestive enzymes.
- C) Fungi receive photosynthetic products in exchange for living in plant root nodules.
- D) Plants receive nitrogen and phosphorus, and fungi receive photosynthetic products.
d
37) Hyphae form a covering over roots. These hyphae create a large surface area that helps to do which of the following?
- A) aid in absorbing minerals and ions
- B) maintain cell shape
- C) increase cellular respiration
- D) anchor a plant
a
38) A plant developed a mineral deficiency after being treated with a fungicide. What is the most probable cause of the deficiency?
- A) Mineral receptor proteins in the plant membrane were not functioning.
- B) Mycorrhizal fungi were killed.
- C) Active transport of minerals was inhibited.
- D) Proton pumps reversed the membrane potential.
b
39) We would expect the greatest difference in plant health between two groups of plants of the same species, one group with mycorrhizae and one group without mycorrhizae, in an environment ________.
- A) where nitrogen-fixing bacteria are abundant
- B) that has soil with poor drainage
- C) in which the soil is relatively deficient in mineral nutrients
- D) that is near a body of water, such as a pond or river
c
40) Which of the following is a primary difference between ectomycorrhizae and endomycorrhizae?
- A) Endomycorrhizae have thicker, shorter hyphae than ectomycorrhizae.
- B) Ectomycorrhizae do not penetrate root cells, whereas endomycorrhizae grow into invaginations of the root cell membranes.
- C) Endomycorrhizae are more common than ectomycorrhizae.
- D) There are no significant differences between ectomycorrhizae and endomycorrhizae.
Answer: B
b
41) Carnivorous plants have evolved mechanisms that trap and digest small animals. The products of this digestion are used to supplement the plant's supply of ________.
- A) energy
- B) carbohydrates
- C) lipids and steroids
- D) nitrogen and other minerals
d
42) Epiphytes are ________.
- A) aerial vines common in tropical regions
- B) plants that live in poor soil and digest insects to obtain nitrogen
- C) plants that grow on other plants but do not obtain nutrients from their hosts
- D) plants that have a symbiotic relationship with fungi
c
43) While hiking in a forest, you notice an unusual plant growing on the branches of a tree. What will help you to determine if this plant is epiphytic or parasitic?
- A) If the plant is green, it is epiphytic; if not, then it is parasitic.
- B) The root of an epiphytic plant will be in the soil, but a parasitic plant will grow from the trunk of a tree.
- C) The roots of a parasitic plant will penetrate under the bark into the tree xylem, and the roots of epiphytic plant will not.
- D) The epiphytic plant will have large water collecting leaves, and the parasitic plant will not.
c