ESTUDYR
PCA EXAM INSECTS, MITES, AND INVERTEBRATES
MOST TESTED QUESTIONS AND ANSWERS GRADED
A+ WITH RATIONALES
Question 1
Which structures are included in chewing mouthparts?
A. Stylet, proboscis, labium, maxillary sheath
B. Proboscis, labrum, hypopharynx, siphon tube
C. Labrum, mandibles, hypopharynx, and labrum-epipharynx
D. Labium, siphon tube, stylet, and haltere
Correct Answer: C. Labrum, mandibles, hypopharynx, and labrum-epipharynx
Rationale:
Chewing mouthparts are adapted for biting and grinding solid food. The mandibles perform the
cutting action, while the labrum and hypopharynx assist with manipulation and digestion. These
structures are common in beetles, grasshoppers, and caterpillars.
Question 2
Piercing-sucking mouthparts function primarily to:
A. Tear and grind plant tissue
B. Absorb liquid through sponge action
C. Lap liquid using tongue-like structures
D. Pierce plant or animal tissue and suck internal fluids
Correct Answer: D. Pierce plant or animal tissue and suck internal fluids
Rationale:
Piercing-sucking mouthparts use needle-like stylets to penetrate tissue and extract fluids such as
plant sap or blood. These mouthparts are characteristic of aphids, mosquitoes, and true bugs.
Question 3
Blood-feeding mouthparts are specialized to:
, ESTUDYR
A. Grind plant leaves efficiently
B. Filter solid particles from liquid
C. Prevent blood clotting while feeding through enzyme injection
D. Tear host tissue into fragments
Correct Answer: C. Prevent blood clotting while feeding through enzyme injection
Rationale:
Blood-feeding insects inject anticoagulant enzymes to keep blood flowing while feeding. This
ensures efficient intake of nutrients and is characteristic of mosquitoes, fleas, and ticks.
Question 4
Rasping-sucking mouthparts primarily function by:
A. Piercing stems deeply with stylets
B. Siphoning nectar from flowers
C. Sponging liquid from surfaces
D. Scraping plant tissue and sucking the released sap
Correct Answer: D. Scraping plant tissue and sucking the released sap
Rationale:
These mouthparts scrape plant surfaces before sucking fluids. Thrips are classic examples and
often cause silvery or scarred plant damage.
Question 5
Siphoning mouthparts are best described as:
A. Needle-like piercing structures
B. Sponge-like absorbing organs
C. Chewing mandibles with cutting edges
D. Coiled feeding tubes used to suck liquids such as nectar
Correct Answer: D. Coiled feeding tubes used to suck liquids such as nectar
Rationale:
Butterflies use siphoning mouthparts called proboscises, which uncoil to draw nectar. They are
specialized for liquid feeding only.
PCA EXAM INSECTS, MITES, AND INVERTEBRATES
MOST TESTED QUESTIONS AND ANSWERS GRADED
A+ WITH RATIONALES
Question 1
Which structures are included in chewing mouthparts?
A. Stylet, proboscis, labium, maxillary sheath
B. Proboscis, labrum, hypopharynx, siphon tube
C. Labrum, mandibles, hypopharynx, and labrum-epipharynx
D. Labium, siphon tube, stylet, and haltere
Correct Answer: C. Labrum, mandibles, hypopharynx, and labrum-epipharynx
Rationale:
Chewing mouthparts are adapted for biting and grinding solid food. The mandibles perform the
cutting action, while the labrum and hypopharynx assist with manipulation and digestion. These
structures are common in beetles, grasshoppers, and caterpillars.
Question 2
Piercing-sucking mouthparts function primarily to:
A. Tear and grind plant tissue
B. Absorb liquid through sponge action
C. Lap liquid using tongue-like structures
D. Pierce plant or animal tissue and suck internal fluids
Correct Answer: D. Pierce plant or animal tissue and suck internal fluids
Rationale:
Piercing-sucking mouthparts use needle-like stylets to penetrate tissue and extract fluids such as
plant sap or blood. These mouthparts are characteristic of aphids, mosquitoes, and true bugs.
Question 3
Blood-feeding mouthparts are specialized to:
, ESTUDYR
A. Grind plant leaves efficiently
B. Filter solid particles from liquid
C. Prevent blood clotting while feeding through enzyme injection
D. Tear host tissue into fragments
Correct Answer: C. Prevent blood clotting while feeding through enzyme injection
Rationale:
Blood-feeding insects inject anticoagulant enzymes to keep blood flowing while feeding. This
ensures efficient intake of nutrients and is characteristic of mosquitoes, fleas, and ticks.
Question 4
Rasping-sucking mouthparts primarily function by:
A. Piercing stems deeply with stylets
B. Siphoning nectar from flowers
C. Sponging liquid from surfaces
D. Scraping plant tissue and sucking the released sap
Correct Answer: D. Scraping plant tissue and sucking the released sap
Rationale:
These mouthparts scrape plant surfaces before sucking fluids. Thrips are classic examples and
often cause silvery or scarred plant damage.
Question 5
Siphoning mouthparts are best described as:
A. Needle-like piercing structures
B. Sponge-like absorbing organs
C. Chewing mandibles with cutting edges
D. Coiled feeding tubes used to suck liquids such as nectar
Correct Answer: D. Coiled feeding tubes used to suck liquids such as nectar
Rationale:
Butterflies use siphoning mouthparts called proboscises, which uncoil to draw nectar. They are
specialized for liquid feeding only.
