PCA Weeds Exam 2026/2027 ACTUAL QUESTIONS
WITH ANSWERS GRADED A+
• Cotyledons -✓✓ first leaf or first pair of leaves produced by the embryo of a seed plant
• First true leaf -✓✓ first leaves to emerge after cotyledons
• Collar -✓✓ Region in grasses at the junction of the sheath and blade, often lighter
colored than surrounding tissue
• Leaf blade -✓✓ flattened part of leaf
• Node -✓✓ Meristematic point on a stem where one or more leaves arise
• Internode -✓✓ Segment of plant between nodes
• Leaf sheath -✓✓ Basal portion of a leaf, wrapped around the stem above a node.
Almost exclusively monocots
• Petiole -✓✓ The stalk of a leaf, which joins the leaf to a node of the stem.
• Auricle -✓✓ Small lobe or ear-shaped appendage found at the base of the leaf blade
of grasses. Aids in seedling identification
• Ligule -✓✓ A membranous or hairy structure on the inside of a leaf at the junction of
the leaf blade and sheath
• Awn -✓✓ A bristlelike appendage in grasses, usually a continuation of the mid-vein of
the bracts surrounding the flower
• Hypocotyl -✓✓ The stem derived from the portion of the embryo located between the
cotyledons and the radicle
• Inflorescence -✓✓ cluster of flowers
• Coleoptile -✓✓ The covering of the young shoot of the embryo of a grass seed.
• Tuber -✓✓ a swollen underground stem
• Rhizome -✓✓ a horizontal, underground stem that produces new leaves, shoots, and
roots
,• Stolon -✓✓ a horizontal branch from the base of plant that produces new plants from
buds at its tips
• Bulbs -✓✓ the round parts of some plants that are underground
• Recognize the key features used to identify grass seedlings -✓✓ Leaf blade, collar,
ligule, sheath
• Recognize the key features used to identify broadleaf seedlings -✓✓ Roots, leaf
arrangement, leaf blade, leaf veins, cotyledons, true leaves
• What weeds are poisonous to animals? -✓✓ Jimsonweed, Nightshades, Common
groundsel, coast fiddleneck, yellow starthistle
• Identify types of vegetative propagules. -✓✓ Runners, suckers, stolons, buds,
rhizomes, bulbs
• List of unique seed or vegetative growth structures that plants have which aid in
dispersal -✓✓ Plants with burs or spiked seeds that catch in animal fur, plants that
disperse their seed with tumbling plant parts, plants with seed that are pappus-bearing
for dispersal by wind,
plants which spread with vegetative propagules
plants that produce prolific small seed
• Examples of plants with burs or spiked seeds that catch in animal fur -✓✓ Filaree,
puncturevine, wild oat, foxtail barley, hare barley
• Examples of plants that disperse their seed with tumbling plant parts -✓✓ Russian
thistle
• Examples of plants with seed that are pappus-bearing for dispersal by wind -✓✓ Hairy
fleabane, common groundsel, cattails
• Examples of plants which spread with vegetative propagules -✓✓ Johnsongrass,
yellow nutsedge, field bindweed
• Examples of plants that produce prolific small seed -✓✓ Purslane, pigweed,
smallflower umbrella sedge
• List information that should be recorded when monitoring for weeds. -✓✓ What weeds
are present, where weeds are present, weather conditions, stage of weed growth
• List resources to assist in weed identification -✓✓ UC IPM, Weed Pest Identification
Monitoring Cards, CAC
, • Function of the xylem (apoplast) -✓✓ Nonliving tissue in plants that functions primarily
to conducct water and mineral nutrients from roots to the shoot
• Function of the phloem (symplast) -✓✓ Living tissue in plants that functions primarily to
transport metabolic compounds such as sugars from the site of synthesis or storage to
the site of utilization
• Function of chloroplast -✓✓ Contains chlorophyll which absorbs light energy for
photosyntheis
• Function of membranes -✓✓ Provide a semi-permeable barrier & control the
movement of substances
• Function of endodermis -✓✓ Ring of cells surrounds vascular cylinder
Cell walls are waterproof
Water can only enter vascular cylinder by moving through endodermal cells
Allows plant to control inward flow
• Function of epidermis -✓✓ Outermost layer of cells covering all parts of the primary
plant body above and below ground
• Function of cuticle -✓✓ prevents water loss
• Function of apical meristem -✓✓ Meristem at the tip of the root or shoot in a vascular
plant, capable of cell division and plant growth
• Function of root hairs -✓✓ these structures increase the surface area of the roots so
that they can absorb water efficiently
• Function of root tip (meristem) -✓✓ Point of active cell division within roots
• Function of stomata -✓✓ controls the entering and exiting of gases
• Describe the conditions necessary for weed seeds to germinate -✓✓ Adequate water,
light, temperature
• Compare how differing weed germination requirements affect management decisions.
-✓✓ Seedlings are most vulnerable, so different germination requirements will influence
the management decision as to which method of germination will be used pre- or post-
plant
• Define seed dormancy -✓✓ State in which viable seeds do not germinate. Seeds have
to break dormancy before germination.
WITH ANSWERS GRADED A+
• Cotyledons -✓✓ first leaf or first pair of leaves produced by the embryo of a seed plant
• First true leaf -✓✓ first leaves to emerge after cotyledons
• Collar -✓✓ Region in grasses at the junction of the sheath and blade, often lighter
colored than surrounding tissue
• Leaf blade -✓✓ flattened part of leaf
• Node -✓✓ Meristematic point on a stem where one or more leaves arise
• Internode -✓✓ Segment of plant between nodes
• Leaf sheath -✓✓ Basal portion of a leaf, wrapped around the stem above a node.
Almost exclusively monocots
• Petiole -✓✓ The stalk of a leaf, which joins the leaf to a node of the stem.
• Auricle -✓✓ Small lobe or ear-shaped appendage found at the base of the leaf blade
of grasses. Aids in seedling identification
• Ligule -✓✓ A membranous or hairy structure on the inside of a leaf at the junction of
the leaf blade and sheath
• Awn -✓✓ A bristlelike appendage in grasses, usually a continuation of the mid-vein of
the bracts surrounding the flower
• Hypocotyl -✓✓ The stem derived from the portion of the embryo located between the
cotyledons and the radicle
• Inflorescence -✓✓ cluster of flowers
• Coleoptile -✓✓ The covering of the young shoot of the embryo of a grass seed.
• Tuber -✓✓ a swollen underground stem
• Rhizome -✓✓ a horizontal, underground stem that produces new leaves, shoots, and
roots
,• Stolon -✓✓ a horizontal branch from the base of plant that produces new plants from
buds at its tips
• Bulbs -✓✓ the round parts of some plants that are underground
• Recognize the key features used to identify grass seedlings -✓✓ Leaf blade, collar,
ligule, sheath
• Recognize the key features used to identify broadleaf seedlings -✓✓ Roots, leaf
arrangement, leaf blade, leaf veins, cotyledons, true leaves
• What weeds are poisonous to animals? -✓✓ Jimsonweed, Nightshades, Common
groundsel, coast fiddleneck, yellow starthistle
• Identify types of vegetative propagules. -✓✓ Runners, suckers, stolons, buds,
rhizomes, bulbs
• List of unique seed or vegetative growth structures that plants have which aid in
dispersal -✓✓ Plants with burs or spiked seeds that catch in animal fur, plants that
disperse their seed with tumbling plant parts, plants with seed that are pappus-bearing
for dispersal by wind,
plants which spread with vegetative propagules
plants that produce prolific small seed
• Examples of plants with burs or spiked seeds that catch in animal fur -✓✓ Filaree,
puncturevine, wild oat, foxtail barley, hare barley
• Examples of plants that disperse their seed with tumbling plant parts -✓✓ Russian
thistle
• Examples of plants with seed that are pappus-bearing for dispersal by wind -✓✓ Hairy
fleabane, common groundsel, cattails
• Examples of plants which spread with vegetative propagules -✓✓ Johnsongrass,
yellow nutsedge, field bindweed
• Examples of plants that produce prolific small seed -✓✓ Purslane, pigweed,
smallflower umbrella sedge
• List information that should be recorded when monitoring for weeds. -✓✓ What weeds
are present, where weeds are present, weather conditions, stage of weed growth
• List resources to assist in weed identification -✓✓ UC IPM, Weed Pest Identification
Monitoring Cards, CAC
, • Function of the xylem (apoplast) -✓✓ Nonliving tissue in plants that functions primarily
to conducct water and mineral nutrients from roots to the shoot
• Function of the phloem (symplast) -✓✓ Living tissue in plants that functions primarily to
transport metabolic compounds such as sugars from the site of synthesis or storage to
the site of utilization
• Function of chloroplast -✓✓ Contains chlorophyll which absorbs light energy for
photosyntheis
• Function of membranes -✓✓ Provide a semi-permeable barrier & control the
movement of substances
• Function of endodermis -✓✓ Ring of cells surrounds vascular cylinder
Cell walls are waterproof
Water can only enter vascular cylinder by moving through endodermal cells
Allows plant to control inward flow
• Function of epidermis -✓✓ Outermost layer of cells covering all parts of the primary
plant body above and below ground
• Function of cuticle -✓✓ prevents water loss
• Function of apical meristem -✓✓ Meristem at the tip of the root or shoot in a vascular
plant, capable of cell division and plant growth
• Function of root hairs -✓✓ these structures increase the surface area of the roots so
that they can absorb water efficiently
• Function of root tip (meristem) -✓✓ Point of active cell division within roots
• Function of stomata -✓✓ controls the entering and exiting of gases
• Describe the conditions necessary for weed seeds to germinate -✓✓ Adequate water,
light, temperature
• Compare how differing weed germination requirements affect management decisions.
-✓✓ Seedlings are most vulnerable, so different germination requirements will influence
the management decision as to which method of germination will be used pre- or post-
plant
• Define seed dormancy -✓✓ State in which viable seeds do not germinate. Seeds have
to break dormancy before germination.
