AGRONOMY 114 Exam 1 Page 1

NAME:

DIRECTIONS:

MARK THE ONE BEST ANSWER ON YOUR ANSWER SHEET.

1. The hilum is the

a) point of entry for the pollen tube

b) the outer layer of the cotyledon

c) tip of the radicle

d) point of attachment of the seed to the legume

e) point of origin of the epicotyl

2. Which phrase is true?

a) warm air holds less moisture than cool air

b) precipitation seldom occurs with downward moving air

c) ascending air warms at the rate of 1 degree per 100 m

d) incresasing air pressure decreases air density

e) descending air cools

3. High relative humidity would

a) increase evapotranspiration

b) occur in a continental tropical air mass

c) cause fast drying conditions

d) decrease evapotranspiration

e) decrease photosynthesis

4. Of the following agronomic classifications, which crop is

least likely to be eaten by man or animal?

a) forage

b) cereal

c) green manure

d) grain

e) pulse

5. The part of a plant cell directly involved in protein

synthesis is the

a) plastid

b) ribosome

c) vacuole

d) mitochondrion

e) plasma membrane

6. Nodulation in soybeans is an example of

a) a necessary plant process

b) symbiosis

c) translocation

d) palisade parenchyma

e) a process not associated with Rhizobia

AGRONOMY 114 Exam 1 A Page 2

7. What world crop is best known for producing pasta and bread

products:

a) corn

b) soybeans

c) rice

d) wheat

e) oats

8. Farmer Debville believes she was sold a mixture of wheat seeds.

Part of the seed lot contained seeds which were vitreous, had

a large germ area, and a small brush area. The remaining seeds

were enclosed in an awned hull. Her seed lot contains

1) soft red winter wheat and hard red spring wheat

2) hard red spring wheat and durum wheat

3) hard red spring wheat and durum wheat

4) soft red winter wheat and barley

5) hard red winter wheat and durum wheat

9. Silas Farmer sufferred a crop loss when his corn seedlings

withered in May due to drought. In order to produce a crop

he had to replant his fields with sorghum. The sorghum can

be called a(n)

a) emergency crop

b) cover crop

c) supplementary crop

d) trap crop

e) catch crop

10. You were shown a formula for calculation of Growth Degree

Days, a concept to determine zones of adaptation of corn

hybrids. Which of the following formulae is correct?

a) Max. temp + min. temp + 50 degrees

2

b) Max. temp - min. temp + 50 degrees

2

c) Max. temp + Min. temp - 50 degrees

2

d) Max. temp - Min. temp - 50 degrees

2

11. If you were a plant breeder, how would you manipulate plant

cells to increase the digestibility of red clover?

a) increase lignin content of cell walls

b) increase plant height

c) decrease the number of rhizomes

d) decrease cell wall lignin content

e) develop larger cells

AGRONOMY 114 Exam 1 A Page 3

12. You are in a contest in which everyone is given a seed to

plant. A month later a judge will measure the height of each

plant. Which of the following hormones could be added to

enhance plant growth?

a) Ethylene

b) Lanolin

c) Gibberellic Acid

d) Anthocyanin

e) Insulin

13. In what zone of the atmosphere are clouds formed?

a) stratosphere

b) climosphere

c) ionosphere

d) hydrosphere

e) troposphere

14. At 4 am in the morning soil temperatures should be the coolest

at what region?

a) 1 cm

b) 2 cm

c) 4 cm

d) 6 cm

e) 8 cm

15. Horizontal stems growing above ground are called

a) suckers

b) rhizomes

c) stolons

d) haplocorm

e) tillers

16. The site of photosynthesis in a living organism is

a) the cell wall

b) the cuticle

c) a form of ribosome

d) a form of plastid

e) a form of mitochondria

17. If a sorghum (short day plant) variety adapted to central Iowa

was grown in Central Minnesota, the plants would

a) grow taller and flower earlier

b) grow taller and flower later

c) grow shorter and flower earlier

d) grow shorter and flower later

e) have the same height as those in Iowa, but would flower

earlier

18. Which crop would precede corn if you wanted to spend the least

amount of money on N fertilizer?

a) corn

b) soybeans

c) sunflowers

d) red clover

e) alfalfa

AGRONOMY 114 Exam 1 A Page 4

19. Which of the following is a modified stem for carbohydrate

storage?

a) peanuts

b) beets

c) potatoes

d) turnips

e) carrots

20. In order to measure the amount of water movement within a

plant, a person would monitor the:

a) stolon

b) phloem

c) cuticle

d) xylem

e) root hairs

21. One of the ISU logos shows Cy, (the mascot) rising up out of a

tornado with cyclonic air movement. If drawn correctly for the

northern hemisphere, the air circulation pattern looking down

from the eyes of our beloved Cy would be

a) right to left

b) north to south

c) clockwise

d) counter-clockwise

e) west to east

22. The forage legume, birdsfoot trefoil, is easy to identify

because the leaves look like they have 5 leaflets per leaf

instead of 3. This is because the two lower leaflet-like

structures are attached to the base of the petiole near the

stem. These 2 leaflet-like structures are called

a) petioules

b) stipules

c) sheaths

d) auricles

e) ligules

23. If a short day plant native to Iowa was planted in Texas, what

would the result be?

a) The plant would grow and flower normally

b) The plant would grow taller than normal and produce a normal

yield

c) The plant would be shorter than normal and flower early

d) The plant would grow taller than normal and but produce a

low yield

e) The plant would be shorter than normal and not flower nor

produce grain

AGRONOMY 114 Exam 1 A Page 5

24. The Iowa State placekicker hits a 52-yard field goal in a

hard rain with the help from a southerly breeze. The low

pressure cell causing this rain is probably located over the

state of

a) Missouri (south of IA)

b) Minnesota (north of IA)

c) Illinois (east of IA)

d) Oklahoma (southwestern U.S.)

e) Nebraska (west of IA)

25. Soybeans have both determinate and indeterminate growth types.

Determinate soybeans

a) develop most of the vegetative growth before flowering

b) are more drought tolerant during the reproductive period

c) grow taller and are more susceptible to lodging

d) vegetative and reproductive periods overlap for an extended

period of time

e) become etiolated at low plant densities

26. One of the demonstrations in the greenhouse involved cutting

off a soybean seedling in the region of the hypocotyl. The

reason the seedling made no growth after being cut was

a) the stored food for the seedling was removed

b) the cut induced gibberellic acid production which caused

growth to cease

c) the cut induced phosphon formation in the root which

stopped transport through the xylem resulting in the

seedling's death

d) the growing points of the seedling were removed

e) too much of the transpiring tissue was removed and water

accumulated in the plant to the extent that the plant

drowned

27. Native grasses provide excellent nesting habitats for game

birds and other wildlife. If you wanted to establish a native

grass prairie, which species would you choose?

a) reed canarygrass

b) timothy

c) orchardgrass

d) little bluestem

e) hihoe silvergrass

28. Biennials normally

a) produce seed for two years and then die

b) produce seed the second year of growth

c) potentially have the ability to live forever

d) do not produce vegetative growth the second year

e) produce seed the first year and only vegetative growth the

second year

AGRONOMY 114 Exam 1 A Page 6

29. Grass flowers are

a) incomplete because they lack the corolla

b) incomplete because they lack the stamen

c) complete because they have both male and female parts

d) perfect because they have the corolla, calyx, male parts

and female parts

e) imperfect because they lack the pistil

30. The grain from a mature ear of corn weighs half a pound. If

only one ear is produced per stalk, what do you estimate the

yield per acre of this corn to be if you know 1) the plant

population = 24,000 pl/A; 2) a bushel of corn grain = 56 lbs.

a) 128 bu/A

b) 357 bu/A

c) 214 bu/A

d) 150 bu/A

e) 280 bu/A

31. Which of the following is least important as a center of origin

of the important crop families?

a) South America

b) Mexico/Central America

c) Middle East

d) United States

e) China

32. If the temperature was the same at the following locations, in

which city would it be easiest to hit a homerun while playing

baseball?

a) Miami

b) St. Louis

c) Denver

d) Cincinnati

e) Chicago

33. Plant sugars made from photosynthesis are converted into

starches, oils, and proteins. This conversion of sugars

requires energy from the cell which is obtained from

a) sunlight

b) heat

c) chlorophyll

d) ATP

e) carbon dioxide

34. Culms make good bedding for livestock. Which crop would make

the best bedding material?

a) corn

b) wheat

c) sorghum

d) alfalfa

e) soybeans

AGRONOMY 114 Exam 1 A Page 7

35. The following cereal grain would most likely be used for

cake flour

a) hard red winter wheat

b) soft red winter wheat

c) common barley

d) flour corn

e) durum wheat

36. When comparing the leaf angle needed for maximum photosynthetic

rates of only a single leave versus a field of leaves the leaf

angles, respectively, should be

a) horizontal; more vertical

b) horizontal; more drooping

c) vertical; vertical

d) vertical; more horizontal

e) drooping; more horizontal

37. If the outer layer (bark) of a dicot plant is removed or

damaged, which of the following plant structures are likely to

be affected?

a) xylem

b) rhizome

c) chloroplast

d) phloem

e) stolon

38. Which crop is best suited to a semiarid region because it

matures before the dry season?

a) corn

b) rye

c) alfalfa

d) soybeans

e) cotton

39. The raw material for photosynthesis which enters through the

stomata is

a) water

b) nitrogen

c) oxygen

d) carbon dioxide

e) ATP

40. Leaf tissue does not include

a) spongy parenchyma

b) pedicel

c) phloem tissue

d) vascular bundles

e) guard cells

AGRONOMY 114 Exam 1 A Page 8

41. Corn (Hordeum vulgare) in North Africa is used as feed, food,

and for making some beverages. Which statement most accurately

describes this crop?

a) it is a dioecious crop

b) it forms an ear with kernels attached to a cob

c) it produces a spike inflorescence

d) it fixes nitrogen in the roots

e) it is a summer annual

42. You plan on cutting and baling your alfalfa stand. Which type

of air mass would probably result in the fastest drying time and

least nutrient loss for your hay in the Midwest?

a) continental tropical

b) Greenland polar

c) maritime polar

d) continental maritime

e) maritime tropical

43. The translocation of a herbicide from the leaves of a plant

to the rhizomes would

a) be mostly through the xylem

b) proceed along the cuticle

c) be mostly through the phloem

d) be mostly through the rachis

e) be mostly through the rachilla

44. Plant auxins include

a) NAR

b) phosphon

c) phytochrome

d) triphosphate

e) indolacetic acid

45. The physiological reason that plant grow taller in higher

populations is because the plants

a) want to survive

b) want more sunshine

c) want to expend more energy first in growth, then later in seed

d) have higher amounts of auxin in stems

e) need greater LAI in higher populations to survive.

46. Suppose you observed a recently emerged seedling in a sorghum

field that you had planted about 10 days ago and found that

epicotyl was just emerging from the point where two seed leaves

(cotyledons) were seemingly attached to each other. What is

the most probable conclusion from this observation?

a) the sorghum is just beginning to emerge

b) the sorghum was planted too deep

c) the sorghum was not planted at a high enough population

d) the sorghum seedlings might be damaged by insects

e) some weeds in the sorghum field are beginning to emerge

AGRONOMY 114 Exam 1 A Page 9

47. Which of the following crops can better utilize higher sunlight

intensity to produce the most photosynthate?

a) sorghum

b) alfalfa

c) timothy

d) tall fescue

e) soybean

48. High fiber bread compared to normal bread contains more

a) starch

b) bran

c) sugars

d) phloem

e) chloroplasts

49. The vapor pressure deficit in Morocco is probably

a) higher than Iowa in July

b) higher in January than in August

c) lower than Iowa in February

d) suitable for wheat grown in their summer

e) influenced by soil type

50. What usually happens to a volume of air as it rises from the soil

surface to a height of 10,000 ft.?

a) it gets warmer

b) the relative humidity increases

c) it gets dryer

d) it circulates to the left

e) the vapor pressure deficit increases.

AGRONOMY 114 Exam 1 Answers

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

Item # Answer

1 4

2 2

3 4

4 3

5 2

6 2

7 4

8 4

9 5 or 1

10 3

11 4

12 3

13 5

14 1

15 3

16 4

17 2

18 5

19 3

20 4

21 4

22 2

23 3

24 5

25 1

26 4

27 4

28 2

29 1

30 3

31 4

32 3

33 4

34 2

35 2

36 1

37 4

38 2

39 4

40 2

41 3

42 1

43 3

44 5

45 4

46 5

47 1

48 2

49 1

50 2