1. Chlorophyll is found in which cell structure

1. mitochondria
2. ribosome
3. nucleus
4. chloroplast
5. chromosome

2. Which of the following is not a name for members of the secondary root system of grasses?

1. coronal roots
2. seminal roots
3. crown roots
4. adventitious roots
5. permanent roots

3. Corn will emerge from greater planting depths than will soybeans because:

1. less energy is required per unit of distance moved by the coleoptile than by cotyledons
2. the corn seed contains more energy per unit size
3. corn seeds are larger and contain more total energy than soybean seeds
4. epigeal emergence is a better method for passing through the soil than is hypogeal emergence
5. the hypocotyl is able to elongate more than the mesocotyl

4. Which of the following statements is true?

1. cultivation does not damage the secondary roots of corn
2. deep planting of corn lowers the amount of root pruning during cultivation
3. shallow planting lowers the amount of root pruning during corn cultivation
4. root pruning during cultivation will be about equal for deep and shallow plantings of corn
5. corn should be planted 3 to 4 inches deep

1. corn
2. oats
3. peanuts
4. rye
5. barley

6. Sugar beet grows only vegetatively the first year, has both vegetative and reproductive growth the second year, then the plant dies. This is an example of what type of plant?

1. annual
2. perennial
3. winter annual
4. biennial
5. triennial

7. When the U.S. was discovered most of the existing crops (excluding corn) were

1. indigenous
2. inbreds
3. exotics
4. exogenous
5. hybrid varieties

8. What special management should be used for an annual crop that needs vernalization?

1. plant by mid May
2. plant in the fall
3. irrigate when leaves first show signs of wilting
4. plant about 2.5 cm deep in most cases
5. harvest when the plants approach harvest maturity based on seed moisture

Physiology

9. Plant auxins include

1. NAR
2. phosphon
3. phytochrome
4. triphosphate
5. indolacetic acid

10. Sugars and amino acids are two important products synthesized in crop plants. Which of the following is true concerning the site of formation?

1. sugars and amino acids are formed in the roots
2. sugars are formed in the roots, but not amino acids
3. sugars and amino acids are formed in the leaves
4. sugars are formed in the leaves, but not amino acids
5. neither sugars or amino acids are formed in the roots

11. In which situation does the economic yield come nearest to being the same as the biological yield?

1. corn silage
2. haylage
3. sugarbeets with tops chopped for roughage feed
4. grain sorghum
5. potatoes

12. Consider the NAR of a corn plant over a twenty-four hour period. At the time when NAR is lowest, what factor will affect the rate of respiration most?

1. CO2 fixation
2. rate of osmosis
3. light intensity
4. temperature
5. LAI

13. The vapor pressure deficit would probably be highest for which combination?

1. 20 C air at 50% relative humidity (R.H.)
2. 20 C Air at 40% R.H.
3. 30 C air at 60% R.H.
4. 30 C air at 80% R.H.
5. 35 C air at 60% R.H.

14. Precipitation in a semiarid region is usually

1. greater during winter months than during the growing season
2. greatest than in Northwest Iowa
3. greatest during the growing season
4. greatest than in Southwest Iowa
5. greater than in Illinois

15. If the calculated growing degree days(GDD) totaled 1500 GDD at a given date and your corn hybrid was expected to tassel at 1800 GDD, how many more days would it take for the hybrid to reach tasseling if the days averaged 85 F(high) and 75 F(low) temperatures?

1. 2
2. 4
3. 10
4. 30
5. 60

16. The usual precipitation pattern of a semiarid region would probably best fit

17. The dark, deep soils of the Midwest that were developed under tall grass prairies are called

1. mollisols
2. aridisols
3. alfisols
4. colluvial soils
5. glacial soils

18. The O horizon in soils is

1. just below the A horizon
2. just above the R horizon
3. made up of glacial material
4. a topmost layer in some soils
5. sometimes referred to as an E horizon

19. Israeli scientists have found two species of snails that contribute to soil formation in the Negev desert by "foraging" for lichens in limestone formations. These snails change the limestone to soil at a rate of 0.7 to 1.1 tons per hectare per year (vs 0.4 tons per hectare per year contributed by wind deposition). What type of soil would be produced from the lichen activity?

1. loess
2. colluvium
3. alluvium
4. residual
5. lacustrine

20. Suppose after catching ten catfish in the Missouri River you walked back to your house located on the bluffs one mile east of the river. You probably walked across

21. Wilting of plants

1. occurs when the moisture tension at the outer surface of the soil particle water film is about 15 atmospheres
2. is caused by increasing the cell turgor
3. is only a physical condition of the plant and does not affect the plant's physiology
4. occurs more readily when relative humidity is high versus low and other conditions are equal
5. results in the opening of stomata

22. A saturated soil

1. contains gravitational water
2. does not contain gravitational water
3. contains only hygroscopic plus capillary water
4. contains only gravitational water
5. is at field capacity

23. In a clay loam soil, if we were to increase the proportion of sand, which of the following would we expect?

1. A greater surface area of soil particles
2. A greater proportion of macropores
3. A slower rate of drainage
4. A greater percentage of soil organic matter
5. A higher wilting coefficient

24. The formula for available water (AV) is:

25. A soil was found to have poor drainage because of an impervious layer in the soil approximately 12 inches deep.

Which of the following most likely would improve drainage?

1. rotary tillage
2. subsoiling
3. sweep tillage
4. chisel-plow planting
5. till plant

26. The disk plow most closely represents what other implement in purpose and result?

1. rotary tiller
2. field cultivator
3. moldboard plow
4. sweep plow
5. tandem disk harrow

27. Which conservation tillage system would be more suited to wet, cool soils?

1. moldboard plowing, disking, harrowing and planting
2. plow-plant system
3. ridge-planting system
4. slot (no-till) planting system
5. subsoiling-checkrow tillage system

28. Which is more closely related to mulch tillage than clean tillage?

29. Phenotype refers to

1. breeding potential of a plant
2. the performance or appearance of a plant
3. the genetic makeup of the plant
4. the chromosome content of a nucleus
5. the concentration of phenol in the cytoplasm

30. Two primary methods of plant breeding are selection and hybridization. The third method is

1. introduction
2. mass selection
3. back crossing
4. pure line selection
5. producing synthetic varieties

31. Genetic segregation occurs

1. in the F1 population of a cross between inbred lines
2. in the F1 population of a cross between two wheat varieties
3. among the offspring of a corn plant after 7 generations of self pollination
4. among the F2 plants following a cross between two soybean varieties
5. among plants of the BC7 population in a backcross after selecting out the desired characteristic (such as rust resistance)

32. A pea plant is Tt genetically for its height genes (T = tall is dominant over t = short). If this plant is pollinated by an identical plant what will be the ratio of tall to short plants in the resulting offspring?

33. The best measure of seedling vigor would be

1. seed size
2. first leaf colors (depth of greenness)
3. seed weight
4. rate of elongation of seedling root
5. seed color

34. Planting seedcorn with poor germination ability will most likely result in

1. only a reduced stand
2. normal healthy seedlings and good yields
3. higher profits per acre due to lower seed costs for poor seed
4. reduced stand, poor seedling growth and possible yield reductions
5. increased allelopathic problems

35. If a poor stand of soybeans occurred from a June planting on a clean-tilled soil, the most likely reason would be

1. lack of oxygen
2. poor seed-to-soil contact
3. dormant seed
4. cool soil temperatures
5. lack of soil moisture

36. Which factor is likely to make grain grade Sample Grade due to improper storage temperature and humidity?

37. Selective herbicides

1. kill or stunt all plant species on which applied
2. kill only parts of the plant receiving application
3. are always absorbed into the plant and translocated to other parts of the plant
4. depend upon rate and time of application as well as chemical
5. do not include specific instructions for application

38. Which one of the following weeds could be vegetatively spread by field cultivation?

1. velvetleaf
2. sunflower
3. cocklebur
4. lambsquarters
5. quackgrass

39. The life cycle of a weed species that appears as small "patches" of 6-8 plants close together in a random pattern across the field is likely a

1. winter annual
2. summer annual
3. perennial
4. annual grassy weed
5. summer biennial

40. Wild sunflower would likely be the hardest to control in what crop?

41. Complete metamorphosis does not include the

1. adult
2. nymph
3. egg
4. larval stage
5. pupa stage

42. An example of an insect that damages roots is

1. seedcorn maggot
2. wireworm
3. rice weevil
4. European corn borer
5. armyworm

43. In general the most effective stage to control an insect with complete metamorphosis that overwinters in Iowa, such as the northern corn rootworm, is the

1. larval stage
2. egg stage
3. nymph stage
4. adult stage
5. pupal stage

44. Many pest-control specialists believe that measures should be taken to control black cutworm larvae only when it is determined that 3 to 5% of a corn stand has been removed by the insect, unless temperatures are warm, since warm temperatures give corn a developmental advantage over the pest. What is another name for this starting point of control efforts?

45. The term "race" is most closely associated with (and best describes) the term:

1. disease
2. nematode
3. toxin
4. pathogen
5. parasitism

46. Purple stain

1. is a soybean disease which seriously reduces yield
2. is a soybean fungicide
3. is a bacterial disease of soybean which does not affect yield seriously
4. is a chemical used to test germination of soybeans
5. is a fungus disease which does not affect yield seriously

47. Race 25 of Phytophthora Root Rot has been found in Iowa. What does this statement imply?

1. there are 25 known disease races
2. there are 25 different disease symptoms
3. race 25 is the most damaging race of the disease
4. there are 25 different strains of the Phytophthora fungus that can cause the disease
5. this disease has been a problem for at least 25 years

48. There is a disease in flax that is called flax wilt. One day a plant will be healthy and the next day it will wilt then die.

What would you expect to be the reason for this rapid decline of the plant?

49. Protein content (%) in forage

1. increases in grasses with plant age.
2. does not change with plant age.
3. decreases with plant age.
4. increases in grasses as seeds are produced.
5. increases in legume plants with age.

50. What is the maximum drying temperature which should be used for planting seed?

1. 70 degrees F
2. 90 degrees C
3. 110 degrees F
4. 140 degrees F
5. 190 degrees C

51. Harvesting sorghum for grain and mistakenly using the optimum date of harvesting for sorghum silage would likely result in

1. delayed harvest maturity
2. low test weight
3. greater field weathering of grain
4. greater stalk lodging
5. greater combine harvesting efficiency

52. What is the most likely reason for poor quality silage made from a mixture of alfalfa and orchardgrass plants?

1. overgrazing
2. poor cutting frequency
3. low carbohydrate percentage
4. low amounts of butyric acid
5. high amounts of lactic acid