California Pest Control Adviser (PCA) Category E Weeds Exam
SECTION 1: WEED BIOLOGY AND LIFE CYCLES (Questions 1-30)
Question 1
A weed that completes its entire life cycle in one year or less and germinates in
the fall or winter is classified as a:
A) Summer annual
B) Winter annual
C) Biennial
D) Perennial
Answer: B
Rationale: Winter annuals germinate in fall or early winter, grow during winter
and spring, and produce seed/die by early to mid-summer. Summer annuals
germinate in spring and complete their cycle by fall.
Question 2
What is the primary reproductive strategy of annual and biennial weeds?
A) Rhizomes only
B) Stolons only
C) Seeds exclusively
,D) Tubers and bulbs
Answer: C
Rationale: Annual and biennial weeds reproduce exclusively by seed. They lack
vegetative propagules such as rhizomes, stolons, or tubers, which is why
preventing seed production is key to controlling these weeds.
Question 3
A "biennial" weed produces what type of growth in its first year?
A) Flowers and seeds
B) A rosette of leaves
C) Woody bark
D) Rhizomes only
Answer: B
Rationale: Biennials (such as bull thistle) spend their first year in a vegetative
rosette stage, building energy reserves. In the second year, they "bolt" (produce a
flowering stalk), flower, produce seed, and die.
Question 4
,Which term describes a plant that lives for more than two years and can
reproduce by both seeds and vegetative structures?
A) Annual
B) Biennial
C) Perennial
D) Ephemeral
Answer: C
Rationale: Perennials persist through multiple growing seasons, often surviving
via specialized storage organs such as rhizomes, tubers, or bulbs. They can
reproduce both sexually (by seed) and asexually (by vegetative propagules).
Question 5
What is the function of the root tip (meristem) in a weed?
A) Storage of carbohydrates
B) Absorption of water through root hairs
C) Active cell division for root growth
D) Anchoring the plant in soil
Answer: C
, Rationale: The apical meristem at the root tip contains undifferentiated cells that
divide continuously, producing new cells for root growth and elongation. This
allows roots to explore new soil areas for water and nutrients.
Question 6
How does seed size affect the depth from which a weed seed can successfully
germinate?
A) Larger seeds germinate only from shallow depths
B) Smaller seeds can germinate from deeper depths
C) Larger seeds have more stored energy and can germinate from deeper depths
D) Seed size has no effect on germination depth
Answer: C
Rationale: Larger seeds contain more energy reserves, allowing the emerging
seedling to push through more soil before reaching the surface and beginning
photosynthesis. Smaller seeds can only germinate from shallow depths (1-2
inches).
Question 7
Define seed dormancy.
A) A seed that has been killed by extreme temperatures
SECTION 1: WEED BIOLOGY AND LIFE CYCLES (Questions 1-30)
Question 1
A weed that completes its entire life cycle in one year or less and germinates in
the fall or winter is classified as a:
A) Summer annual
B) Winter annual
C) Biennial
D) Perennial
Answer: B
Rationale: Winter annuals germinate in fall or early winter, grow during winter
and spring, and produce seed/die by early to mid-summer. Summer annuals
germinate in spring and complete their cycle by fall.
Question 2
What is the primary reproductive strategy of annual and biennial weeds?
A) Rhizomes only
B) Stolons only
C) Seeds exclusively
,D) Tubers and bulbs
Answer: C
Rationale: Annual and biennial weeds reproduce exclusively by seed. They lack
vegetative propagules such as rhizomes, stolons, or tubers, which is why
preventing seed production is key to controlling these weeds.
Question 3
A "biennial" weed produces what type of growth in its first year?
A) Flowers and seeds
B) A rosette of leaves
C) Woody bark
D) Rhizomes only
Answer: B
Rationale: Biennials (such as bull thistle) spend their first year in a vegetative
rosette stage, building energy reserves. In the second year, they "bolt" (produce a
flowering stalk), flower, produce seed, and die.
Question 4
,Which term describes a plant that lives for more than two years and can
reproduce by both seeds and vegetative structures?
A) Annual
B) Biennial
C) Perennial
D) Ephemeral
Answer: C
Rationale: Perennials persist through multiple growing seasons, often surviving
via specialized storage organs such as rhizomes, tubers, or bulbs. They can
reproduce both sexually (by seed) and asexually (by vegetative propagules).
Question 5
What is the function of the root tip (meristem) in a weed?
A) Storage of carbohydrates
B) Absorption of water through root hairs
C) Active cell division for root growth
D) Anchoring the plant in soil
Answer: C
, Rationale: The apical meristem at the root tip contains undifferentiated cells that
divide continuously, producing new cells for root growth and elongation. This
allows roots to explore new soil areas for water and nutrients.
Question 6
How does seed size affect the depth from which a weed seed can successfully
germinate?
A) Larger seeds germinate only from shallow depths
B) Smaller seeds can germinate from deeper depths
C) Larger seeds have more stored energy and can germinate from deeper depths
D) Seed size has no effect on germination depth
Answer: C
Rationale: Larger seeds contain more energy reserves, allowing the emerging
seedling to push through more soil before reaching the surface and beginning
photosynthesis. Smaller seeds can only germinate from shallow depths (1-2
inches).
Question 7
Define seed dormancy.
A) A seed that has been killed by extreme temperatures
