IOWA COMMERCIAL PESTICIDE APPLICATOR
CATEGORY 1A EXAM SCRIPT 2026
QUESTIONS WITH ANSWERS GRADED A+
◉ C1:Identify specific problems caused by aquatic weeds. Answer:
1)Restriction of recreational activities, 2)foul taste & odor, 3)hinder fish
growth & survival, 4)water flow restrictions, 5)accelerate water loss,
6)accelerate fill, 7)interfere with navigation, 8)offer a home for noxious
insects, 9)water becomes toxic, 10)loss of aesthetic appeal, and increase
maintenance costs.
◉ C1:Recognize two instances when aquatic weeds should be
eliminated from a body of water. Answer: 1) Retention ponds used for
fire control or irrigation systems; 2) exotic, invasive species
◉ C2:Describe how sunlight and nutrients affect plant growth. Answer:
Light: photic zone; water hardness- dissolved calcium & magnesium,
low hardness, soft, prevents good light penetration, high hardness (60-75
ppm) increased light penetration. Nutrients: runoff; eutrophication.
◉ C2:List the three nutrients regulating aquatic plant growth. Answer: 1)
carbon (in the form of bicarbonates), 2) nitrogen, and
3) phosphorus
,◉ C2:Describe how water temperature affects aquatic plant growth.
Answer: Most plants grow best in warming water in spring & early
summer, most die back in fall as water cools, some grow best in late
winter & spring (curlyleaf); a few later in summer (naiads)
◉ C2:Explain why sand is a good substrate in small bodies of water, but
bad in rivers. Answer: Rivers sand shifts, ponds it doesn't matter
◉ C2:Explain why rock and gravel substrates are not conducive to
growth of rooted plants. Answer: They provide little in the way of fertile
sediments for nutrient uptake
◉ C3:Identify three major types of algae. Answer: 1) microscopic, 2)
filamentous, 3) stonewarts (Nitella & Chara)
◉ C3:Differentiate between the four types of flowering plants based on
the habitat they occupy in the aquatic environment. Answer: 1)
submersed plants- water depths of less than 1 foot to 20 feet, 2) free-
floating plants- water surface (duckweed), 3) rooted floating plants-
water depths of 1 to 5 feet (water lotus, pondweed), 4) emergent plants-
water depths less than 3 feet
◉ C3:List four types of leaf arrangement that aid in the identification of
submersed plants. Answer: 1) alternate leaf arrangement- one leaf per
node (pondweed), 2) opposite leaf arrangement- two leaves per node
, (naiads), 3) whorled leaf arrangement- three or more leaves per node
(coontail & elodea), & 4) basal leaf arrangement- does not have an erect
stem (eelgrass)
◉ C3:Discuss why duckweed can be especially problematic in a water
body. Answer: Can completely cover the surface and cause the bottom
layer of water to become anaerobic & unsuitable for fish
◉ C3:Identify the location of leaf emergence for rooted floating plants.
Answer: Underground or in sediment (rhizomes)- American lotus,
spatterdock, water lily, water shield; From stems- pondweeds
◉ C3:Distinguish the two types of emergent plants and give an example
of each. Answer: 1) herbaceous- grass-like plants (cattail, bulrush),
plants with broad leaves (arrowhead, smartweed); 2) woody plants-
(willow, buttonbush)
◉ C4:Identify three major objectives in preventive aquatic plant control.
Answer: 1) prevention of weed spread, 2) elimination of nutrient sources
that support growth, and 3) reduction of shallow areas where plants can
root
◉ C4:List the seven steps to reducing nutrient input through a watershed
management plan. Answer: 1) install sod or native grasses/vegetation
along drainage areas & buffers, 2) stop fertilizing grass in a 10 to 20 foot
strip along a body of water, 3) prevent livestock from entering water, 4)
CATEGORY 1A EXAM SCRIPT 2026
QUESTIONS WITH ANSWERS GRADED A+
◉ C1:Identify specific problems caused by aquatic weeds. Answer:
1)Restriction of recreational activities, 2)foul taste & odor, 3)hinder fish
growth & survival, 4)water flow restrictions, 5)accelerate water loss,
6)accelerate fill, 7)interfere with navigation, 8)offer a home for noxious
insects, 9)water becomes toxic, 10)loss of aesthetic appeal, and increase
maintenance costs.
◉ C1:Recognize two instances when aquatic weeds should be
eliminated from a body of water. Answer: 1) Retention ponds used for
fire control or irrigation systems; 2) exotic, invasive species
◉ C2:Describe how sunlight and nutrients affect plant growth. Answer:
Light: photic zone; water hardness- dissolved calcium & magnesium,
low hardness, soft, prevents good light penetration, high hardness (60-75
ppm) increased light penetration. Nutrients: runoff; eutrophication.
◉ C2:List the three nutrients regulating aquatic plant growth. Answer: 1)
carbon (in the form of bicarbonates), 2) nitrogen, and
3) phosphorus
,◉ C2:Describe how water temperature affects aquatic plant growth.
Answer: Most plants grow best in warming water in spring & early
summer, most die back in fall as water cools, some grow best in late
winter & spring (curlyleaf); a few later in summer (naiads)
◉ C2:Explain why sand is a good substrate in small bodies of water, but
bad in rivers. Answer: Rivers sand shifts, ponds it doesn't matter
◉ C2:Explain why rock and gravel substrates are not conducive to
growth of rooted plants. Answer: They provide little in the way of fertile
sediments for nutrient uptake
◉ C3:Identify three major types of algae. Answer: 1) microscopic, 2)
filamentous, 3) stonewarts (Nitella & Chara)
◉ C3:Differentiate between the four types of flowering plants based on
the habitat they occupy in the aquatic environment. Answer: 1)
submersed plants- water depths of less than 1 foot to 20 feet, 2) free-
floating plants- water surface (duckweed), 3) rooted floating plants-
water depths of 1 to 5 feet (water lotus, pondweed), 4) emergent plants-
water depths less than 3 feet
◉ C3:List four types of leaf arrangement that aid in the identification of
submersed plants. Answer: 1) alternate leaf arrangement- one leaf per
node (pondweed), 2) opposite leaf arrangement- two leaves per node
, (naiads), 3) whorled leaf arrangement- three or more leaves per node
(coontail & elodea), & 4) basal leaf arrangement- does not have an erect
stem (eelgrass)
◉ C3:Discuss why duckweed can be especially problematic in a water
body. Answer: Can completely cover the surface and cause the bottom
layer of water to become anaerobic & unsuitable for fish
◉ C3:Identify the location of leaf emergence for rooted floating plants.
Answer: Underground or in sediment (rhizomes)- American lotus,
spatterdock, water lily, water shield; From stems- pondweeds
◉ C3:Distinguish the two types of emergent plants and give an example
of each. Answer: 1) herbaceous- grass-like plants (cattail, bulrush),
plants with broad leaves (arrowhead, smartweed); 2) woody plants-
(willow, buttonbush)
◉ C4:Identify three major objectives in preventive aquatic plant control.
Answer: 1) prevention of weed spread, 2) elimination of nutrient sources
that support growth, and 3) reduction of shallow areas where plants can
root
◉ C4:List the seven steps to reducing nutrient input through a watershed
management plan. Answer: 1) install sod or native grasses/vegetation
along drainage areas & buffers, 2) stop fertilizing grass in a 10 to 20 foot
strip along a body of water, 3) prevent livestock from entering water, 4)
