2025 PCA WEEDS END OF COURSE ALL QUESTIONS WITH
ANSWERS GUARANTEE A+ 2025/2026
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.
Describe some factors that regulate or break seed dormancy - Scarification/penetration
of hard seed coat, chemical inhibition, temperature
Describe the effect of seed size on dormancy and the depth from which a weed seed
can successfully germinate. - Larger seed can germinate from deeper depths. Smaller
seed can germinate from shallow depths.
Smaller seed is more persistent than larger seed and can remain dormant for longer
periods of time.
Annual Weed - Weed plant that completes its life cycle in 1 year
Perennial Weed - Weed that persists in the community by continuing to grow year after
year
Biennial Weed - Weed that completes its life cycle in 2 years
Summer Annual Weed - Weeds that germinate in the spring or early summer, grow
through summer, flower and set seed by autumn.
Winter Annual Weed - Weeds that germinate in fall or early winter, grow during the
winter or spring, and flower and usually set seed by early to mid-summer
Dicot - Plants with two cotyledons. Generally have net venation and flower parts are
usually found in multiples of four or five.
Monocot - Plants with a single seed leaf. Most have leaves with parallel venation and
flower parts occurring in multiples of three
Describe the influence of seasonal changes on the weed spectrum - Different seasons
will see different groups of weeds present in fields (winter vs summer annuals)
Describe the influence of weed growth on water and nutrient availability to the crop. -
Weeds will out-compete crops for water and nutrient availability, hence why it is
important to manage weeds before they become out of control.
ANSWERS GUARANTEE A+ 2025/2026
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.
Describe some factors that regulate or break seed dormancy - Scarification/penetration
of hard seed coat, chemical inhibition, temperature
Describe the effect of seed size on dormancy and the depth from which a weed seed
can successfully germinate. - Larger seed can germinate from deeper depths. Smaller
seed can germinate from shallow depths.
Smaller seed is more persistent than larger seed and can remain dormant for longer
periods of time.
Annual Weed - Weed plant that completes its life cycle in 1 year
Perennial Weed - Weed that persists in the community by continuing to grow year after
year
Biennial Weed - Weed that completes its life cycle in 2 years
Summer Annual Weed - Weeds that germinate in the spring or early summer, grow
through summer, flower and set seed by autumn.
Winter Annual Weed - Weeds that germinate in fall or early winter, grow during the
winter or spring, and flower and usually set seed by early to mid-summer
Dicot - Plants with two cotyledons. Generally have net venation and flower parts are
usually found in multiples of four or five.
Monocot - Plants with a single seed leaf. Most have leaves with parallel venation and
flower parts occurring in multiples of three
Describe the influence of seasonal changes on the weed spectrum - Different seasons
will see different groups of weeds present in fields (winter vs summer annuals)
Describe the influence of weed growth on water and nutrient availability to the crop. -
Weeds will out-compete crops for water and nutrient availability, hence why it is
important to manage weeds before they become out of control.
