AGRONOMY 114 FINAL Page 1

NAME:

DIRECTIONS:

MARK THE ONE BEST ANSWER ON YOUR ANSWER SHEET.

1. Which plant species, when present, most likely indicates that

the pasture is rangeland pasture?

a) Kentucky bluegrass

b) orchardgrass

c) smooth bromegrass

d) little bluestem

e) tall fescue

2. Which of the following is the most specific level of classification?

a) genus

b) kingdom

c) family

d) class

e) order

3. After getting your seed tested, you find out that a high

percent of seed did not germinate because of physiological

dormancy. What could be a cause of physiological dormancy?

a) chemical scarification

b) mechanical scarification

c) lack of carbon dioxide

d) hormonal inhibition

e) hard seedcoats

4. What are the conditions which would most likely suggest that a farmer

should consider a no-plow system of reduced tillage?

a) heavy soils and/or high pH

b) high rainfall and/or level land

c) clay soils and/or level land

d) rolling land and/or probability of insufficient moisture

e) none of the above

5. In symbiosis as characterized by legume plants and Rhizobium

a) the bacteria furnish energy for the legume plants

b) the legume plants furnish nitrogen for the bacteria

c) the legume plants furnish carbohydrates for the bacteria

d) inoculation is the small swellings on the roots

e) the amount of nodulation on legume plants is greater in

soils high in nitrogen

6. Which of the following is an abiotic cause of plant disease?

a) root-knot nematode

b) iron-deficient soil

c) Aspergillus flavus

d) maize dwarf mosaic virus

e) bacterial blight

AGRONOMY 114 FINAL A Page 2

7. Normally, wheat cannot be grown in arid areas receiving 8

inches (20 cm) of rainfall per year. However, this is done in

some areas of the world at 30oN Lat. without using irrigation.

How could it be done?

a) by planting it deeper in the soil

b) by using a really effective anti-transpirant

c) by growing it during the winter months

d) by using it as a supplementary crop

e) by applying IAA during growth

8. The two most important crop families are?

a) Convolvulaceae and Cucurbitaceae

b) Fabaceae and Plantae

c) Plantae and Zea

d) Zea and Glycine

e) Poaceae and Fabaceae

9. Which characteristics would be best for a temporary cover crop

in spring?

a) cool season grass, perennial

b) cool season grass, annual

c) warm season grass, perennial

d) cool season legume, perennial

e) warm season legume, annual

10. The graph of population development of a predator in comparison

with its prey is likely to:

a) increase sooner in the season.

b) increase later in the season.

c) increase and remain constant through the season.

d) decrease and remain constant through the season.

e) decrease sharply during mid season based on weather.

11. Viricides would most likely control

a) barley yellow dwarf

b) stalk rot

c) ergot

d) corn smut

e) nematodes

12. Which is more closely related to mulch tillage than clean

tillage?

a) warmer soil temperatures in April

b) more soil moisture in March

c) greater ease of rotary hoeing for weeds

d) less snow cover in March

e) less potential for alleopathic damage in a corn-corn

rotation

AGRONOMY 114 FINAL A Page 3

13. For many crops, high night-time temperatures are less desirable

during seed filling stages than for vegetative growth. What is

the most likely reason?

a) maximum LAI is established by the mature stage resulting in

more seed fill

b) the compensation point is lowest during vegetative stages re-

quiring higher temperatures to offset poor light utilization.

c) higher respiration rates during higher night-time temperatures

result in less seed fill

d) NAR approaches zero during rapid vegetative growth requiring

higher optimum temperature than during seed filling

e) net photosynthetic rates approach net assimilation rates

under lower temperatures during the seed filling period re-

sulting in more seed fill

14. Which disease can cause sickness in animals or humans and

with which crop is it associated?

a) purple stain on soybeans

b) rust on oats or small grain

c) maize dwarf mosaic

d) ergot on small grains

e) ergot on soybeans

15. What cereal seed parts are usually missing in low fiber bread

that are present in high fiber bread?

a) mesophyll layers

b) gluten endosperm cells

c) kernel scutellums

d) aleurone and pericarp layers

e) cell walls

16. A plant has reached physiological maturity when its seed has

a) maximum LAI

b) maximum green weight

c) maximum seed set

d) maximum water content

e) maximum dry weight

17. If you need to measure 21.8 feet of row to equal 1/1000 of an

acre, what is the row spacing of the crop?

a) .5 ft

b) 1.0 ft

c) 1.5 ft

d) 2.0 ft

e) 2.5 ft

18. Soil water which is relatively available for plant use is

a) capillary water

b) gravitational water

c) hygroscopic water

d) percolated water

e) not available in soil at field capacity

AGRONOMY 114 FINAL A Page 4

19. After checking your rye crop, you notice the plants are

shorter, and some of the seed heads have large purplish black

bodies that replace the kernel. What is the cause?

a) covered smut

b) ergot

c) scald

d) barley yellow dwarf

e) pythium seed rot

20. One spring day you are walking in the wide open spaces

in one of Iowa's prairies and notice a flower. After

examining the flower you speculate that it could

possibly be self pollinating because it was

a) complete and imperfect

b) complete

c) incomplete and imperfect

d) a dioecious plant

e) incomplete

21. Over 99% of the total water needs of a farm in Central U.S.

is related to crop production. Most of the water used by

crops is for

a) grain moisture

b) stalk moisture

c) root moisture

d) flower structures

e) evapotranspiration

22. The "tip" of a corn seedling emerged through the soil

surface. However, the seedling developed no further (no

leaves or stalk were produced). The best explanation for

this is that the following embryo part had been damaged

a) aleurone

b) growing point

c) coleoptile

d) radicle

e) mesocotyl

23. Which of the following plant-type descriptions would you expect

for a primary noxius weed?

a) slow-growing dicot

b) grass containing a substance toxic to ladybugs

c) fast-growing annual grass reproducing by seeds only

d) fast-growing perennial grass reproducing by rhizomes and seeds

e) slow-growing viny broadleaf with postrate growth habit

and reproducing by seeds

24. If a farmer wants to plant 51 pounds of pure live soybean

seed on an acre of land, the germination of the seed lot is

95 percent and the pure live seed is 90 percent, how many

pounds of the seed lot will he have to plant?

a) 56.7 pounds

b) 62.1 pounds

c) 48.6 pounds

d) 55.0 pounds

e) 43.2 pounds

AGRONOMY 114 FINAL A Page 5

25. A vector is

a) a successful insect predator

b) a man who raises insects for insecticide studies

c) an insect with a complete life cycle

d) a sap-sucking insect that spreads virus diseases

e) a boring insect like the European Corn Borer

26. If one cotyledon is lost from a legume plant at the time of

emergence

a) the plant will be severely stunted

b) the plant will continue to grow almost normally

c) the plant will die

d) the plant will branch and produce more seed than a normal plant

e) the plant will grow taller but weaker than a normal plant

27. What is the reason that a homozygous trait will breed true in

successive generations of off-spring in a self-pollinating crop?

a) the gametes are heterozygous

b) the gametes are diploid

c) the gametes are haploid

d) the undesirable gametes will have lethal genes

e) the gametes will have an allele of the trait that is

identical to the parent.

28. I am a grassy weed that immigrated to the U.S. from Europe. I

reproduce by seeds and rhizomes. My seeds have a small awn on

the lemma and look somewhat like orchardgrass, tall fescue, or

Kentucky bluegrass. I am

a) johnsongrass

b) yellow nutsege

c) hedge bindweed

d) redroot pigweed

e) quackgrass

29. Using extremely high plant populations for corn silage would

likely reduce which yield component?

a) number of leaves per plant

b) number of seeds per ear

c) number of tassels per hectare

d) number of nodes per stem

e) number of plants per hectare

30. I am white and big. Often, I curl. My mother lives in May and

June. I like to play and eat in the grass. I am especially

well known for my devilish acts on crops that follow sod. I am

called

a) seedcorn maggot

b) Northern corn rootworm

c) rice weevil

d) white grub

e) green cloverworm

AGRONOMY 114 FINAL A Page 6

31. Row cultivation for weed control is more likely to increase

which disease

a) ergot

b) ear rot

c) leaf rust

d) root rot

e) smut

32. On a cloudy, early winter day when the soil is not covered with

snow, which of the following depths of soil would be the

coldest when the air temperature went from 50 to 10 degrees F?

a) 1 inch

b) 6 inches

c) 12 inches

d) 24 inches

e) 48 inches

33. The major reason for summer fallowing is

a) to control diseases

b) to control erosion

c) to save soil moisture for the next crop

d) to control insects

e) to prepare the seedbed for the next crop

34. As red clovers matures from the bud stage to the seed producing

stage, which transition is most likely to take place?

a) yield increases, protein decreases, digestibility decreases

b) yield decreases, protein decreases, digestibility decreases

c) yield increases, protein increases, digestibility decreases

d) yield decreases, protein decreases, digestibility increases

e) yield increases, protein decreases, digestibility increases

35. Which implement is used to increase germination for

small-seeded grasses and legumes?

a) field cultivator

b) chisel plow

c) reduced tillage

d) roller packer

e) subsoiler

36. The atmosphere is made up of three layers. Let stratosphere

= S, troposphere = T, and ionosphere = I. If you were an

astronaut returning from the moon, you would pass through the

layers of atmosphere in what order before splashdown?

a) SIT

b) TSI

c) TIS

d) IST

e) ITS

37. The most probable reasons for moldy hay and moldy silage,

respectively, are

a) too wet, too dry

b) too wet, too wet

c) too dry, too wet

d) too dry, too dry

e) chopped too coarse, chopped too fine

AGRONOMY 114 FINAL A Page 7

38. One reason some weeds are especially challenging to manage is

that they reproduce by both seeds and rhizomes. An example of

this type of weed would be:

a) johnsongrass

b) downy brome

c) green foxtail

d) fall panicum

e) large crabgrass

39. The breakdown of carbohydrates in silage is the result of

a) high nitrogen content

b) anaerobic respiration

c) excess acid

d) excess sugar

e) transpiration

40. Which insect is likely to be a problem in the field of wheat?

a) wireworms

b) hessian flies

c) white grubs

d) corn earworms

e) rootworms

41. Which of the following combinations of soil particles would

have the greatest micropore space? Assume an equal volume with

only the ratios within the volume changing.

a) 50% clay and 50% sand

b) 50% clay and 50% silt

c) 50% sand and 50% silt

d) 30% sand, 30% silt and 40% clay

e) 85% clay and 15% sand

42. If an insect were to penetrate a corn plant leaf,

what would it have to pass through first?

a) palisade cells

b) epidermis

c) vascular bundle

d) cuticle

e) mesophyll

43. Rapid, uniform emergence of a hay crop is most important for

a) soil drainage

b) root development

c) salt toxicity

d) weed control

e) growing degree day accumulation

44. The digestibility and protein percentages of grasses and

legumes are generally lowest at what stage?

a) flowering stage

b) tillering stage

c) bud stage

d) boot or prebud stage

e) leafy stage

AGRONOMY 114 FINAL A Page 8

45. The crop most responsible for increased erosion rates in Iowa

in the last 50 years is

a) oats

b) alfalfa

c) wheat

d) soybeans

e) corn

46. Which of the following is not a generally accepted example

of seed dormancy?

a) hard seed

b) impermeable seed

c) scarified seed

d) immature embryos

e) presence of germination inhibitors

47. The limitation of the warm germination test is that

a) it doesn't necessarily predict field performance

b) the test takes too much time

c) its results are not influenced by the handling and storage

conditions of the seed

d) its results are not influenced by physical dormancy of the seed

e) its results do not influence the pure live seed content

48. Suppose a farmer sprayed a herbicide on soybeans near

physiological maturity to cause rapid drying of the

plant and allow earlier harvesting. The harvested

seeds, when planted next spring, did not germinate

properly. The herbicide probably was

a) a contact herbicide

b) a translocated herbicide

c) a soil sterilant

d) chosen for its selectivity

e) applied at two times the normal rate

49. Which insect has a gradual(incomplete) life cycle?

a) alfalfa webworm

b) leafhopper

c) bean leaf beetle

d) white grub

e) Angoumois grain moth

50. Which of the following is not considered to be a primary

factor influencing soil formation?

a) climate

b) time

c) vegetation

d) runoff

e) parent material

51. Premergence herbicides should be

a) contact herbicides

b) foliar herbicides

c) non-selective

d) applied to the soil

e) applied as fungicides

AGRONOMY 114 FINAL A Page 9

52. Which defines desiccant?

a) a material which causes the plant to dry out and die

b) a material that decreases elongation of stems

c) a material which causes leaves to separate from the plant

d) a material which decreases the abortion rate or loss of

flowers on plants

e) a material which enables a plant to maintain cell

turgidity under drought stress

53. Grain stored in a bin with high temperatures and moisture will

result in

a) cooler grain temperatures

b) greater respiration

c) loss in protein

d) greater test weight

e) both b and c

54. Stages of development in organisms that have gradual

metamorphosis do not include

a) nymph

b) larvae

c) egg

d) adult

e) none of the above

55. I am nicknamed "Bunt". Some people call me "stinky". I live

on wheat and other small grains. I replace kernels with black

spores. My ancestry is fungi. I am called

a) ergot

b) leaf

c) scald

d) gibberella ear rot

e) covered smut

56. Which species would most likely be a problem in a field of

winter wheat?

a) quackgrass

b) johnsongrass

c) downy brome

d) yellow nugsedge

e) swamp smartweed

57. Perennial pasture and hay crops will usually compete more

strongly with weeds when

a) the weeds are perennials rather than annuals

b) the soil pH is at a lower level

c) a companion crop has not been used in establishing the crop

d) the soil fertility is at a high level

e) pre-emergence herbicides are not used

58. Parasites that live and complete their life cycle only on

living plant tissues are called

a) facultative

b) obligate

c) mutual

d) pathogenic

e) saprophytic

AGRONOMY 114 FINAL A Page 10

59. A soil which is formed from parent material without movement

away from the original bedrock would be of a type called

a) alluvial

b) colluvial

c) lacustrine

d) residual

e) loess

60. "Triple fusion" is a process associated with

a) hygroscopic water shells

b) formation of endosperm

c) the pedigree method of breeding

d) nuclear power plants

e) blending of breeder's, foundation and certified seed

61. Which species' larvae is whitish and worm-like with a brown head,

and tends to be a problem in fields of maize following maize?

a) southern Corn Rootworm

b) northern Corn Rootworm

c) western Corn Rootworm

d) both b and c

e) all of the above

62. Lodging resistance can most likely be improved at the expense of

a) photosynthesis

b) digestibility

c) transpiration

d) translocation

e) germination

63. The simplest cell based on evolutionary evidence would most

likely be a/an

a) root cell

b) rhizome cell

c) cotyledonary cell

d) chloroplast cell

e) prokaryotic cell

64. This type of subsurface secondary tillage tends to have wide

horizontal V-shaped sweeps that are used to cut roots without

inverting the topsoil, thereby conserving moisture. What type

of tillage is this?

a) conservation tillage

b) sweep tillage

c) a type of full width

d) a and b

e) all of the above

65. Which pair of words most closely fit together between function

of anatomical part and ability to carry out the function?

a) phloem - systemic herbicide

b) root hair - pollination

c) corolla - tetrazolium testing

d) stipule - no-till

e) cotyledon - mutualism

AGRONOMY 114 FINAL A Page 11

66. Spreading ground limestone on soil to reduce soil acidity is a

common agricultural practice. What is another benefit of liming

acidic soils?

a) improves soil structure

b) benefits soil organisms that decompose organic material

c) increases the availability of phosphorus and potassium

d) adds calcium and magnesium as nutrients

e) all of the above

67. The phenotypic F1 ratio of a monohybrid cross: male = Aa;

female = Aa would be _____ if big A is dominant and small a

is recessive.

a) 1:1

b) 3:1

c) 2:2

d) 4:0

e) 1:4

68. Leaf stomata are more likely to be closed July 10 when the

plant is growing in

a) a sandy loam soil

b) a clay loam soil

c) soils with more micropores

d) soils with higher organic matter

e) soils with higher fertility levels

69. A wiseman once stated, "Don't judge someone or something by its

color; eyes can deceive but the heart does not." Using this

message, which one of the following statements is true?

a) John Deere owners have small hearts

b) the color of green is most deceiving

c) green machines are big on "green" small on "machine"

d) John Deere carries the same message as a "Dear John" letter

e) all of the above

70. The Great Plains receives less precipitation than the Pacific

Northwest in the U.S. because air

a) travels over more land to get to the Great Plains

b) travels over colder land in the Pacific Northwest

c) travel toward sea level in the Great Plains

d) travels over less fertile soil in the Great Plains than in

the Pacific Northest

e) has cyclonic movement in the Great Plains and anticyclonic

movement in the Pacific Northwest

71. In the midwestern part of the U.S., late dates of planting of

summer annual crops most usually result in poor stands

because of

a) excess surface soil moisture

b) planting depth slightly deeper than normal

c) deficient surface soil moisture

d) the primary effect of temperature on germination

e) the effect of long days on short-day plants

AGRONOMY 114 FINAL A Page 12

72. Which pair of factors are primarily responsible for

differences in plants?

a) genes and chromosomes

b) cytoplasm and nucleus

c) segregation and selection

d) hybridization and selection

e) genetics and environment

73. Bacillus thuringiensis is a

a) parasitic insect

b) vector

c) predatory insect

d) host species

e) parasitic bacterium

74. A young soil, as compared to a mature soil, would generally

have

a) less definite profile development

b) well developed surface drainage

c) a well defined B horizon

d) been developed under forest vegetation

e) hilly topography

75. Irrigated arid regions tend to have high temperatures and low

humidity. Because of these conditions, evapotranspiration rates

generally exceed precipitation during which times of the year?

a) spring and summer

b) fall and winter

c) summer and fall

d) winter and spring

e) most of the year

AGRONOMY 114 FINAL Exam Answers

(Answers may not be 100% correct; check with instructor if questionable)

Question -- Answer

1 4

2 1

3 4

4 4

5 3

6 2

7 3

8 5

9 2

10 2

11 1

12 2

13 3

14 4

15 4

16 5

17 4

18 1

19 2