Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
Choose an option to check your answer.
A.
Water loss
B.
Nerve conduction
C.
Muscle contraction
D.
Bone mineralization
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Correct Answer: A. Water loss
Explanation:
The keratinized reptilian skin reduces evaporation, allowing more effective terrestrial life. It is an adaptation for protection against drying.
Choose an option to check your answer.
A.
Injury, infection, and water imbalance
B.
Instant loss of all hormones
C.
Complete absence of muscles
D.
Failure of taxonomy
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Correct Answer: A. Injury, infection, and water imbalance
Explanation:
The integument protects against injury, pathogens, and water loss or gain. Without it, the body cannot maintain stable internal conditions effectively.
Choose an option to check your answer.
A.
Keratin
B.
Hemoglobin
C.
Insulin
D.
Chlorophyll
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Correct Answer: A. Keratin
Explanation:
Keratin is a structural protein found in many vertebrate integumentary derivatives, including mammalian hair and reptilian scales.
Choose an option to check your answer.
A.
Photoreceptor
B.
Thermoreceptor
C.
Baroreceptor
D.
Osmoreceptor
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Correct Answer: A. Photoreceptor
Explanation:
Photoreceptors detect light. In eyes or simple light-sensitive organs, they allow animals to respond to illumination, shadows, and visual signals.
Choose an option to check your answer.
A.
Sliding filament mechanism
B.
Lymphocyte activation
C.
Melanin production
D.
Glomerular filtration
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Correct Answer: A. Sliding filament mechanism
Explanation:
Skeletal muscle contraction depends on actin and myosin filaments sliding past one another. Blocking their interaction prevents force production and therefore movement.
Choose an option to check your answer.
A.
Thermoregulation
B.
Gamete production
C.
Bone formation only
D.
Sound detection
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Correct Answer: A. Thermoregulation
Explanation:
Sweat evaporation removes heat from the body surface. This shows how the skin acts in thermoregulation, not just as a protective barrier.
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A.
Body covering adaptations
B.
Circulatory pumps
C.
Endocrine messengers
D.
Digestive enzymes
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Correct Answer: A. Body covering adaptations
Explanation:
Scales, feathers, and hair are body coverings derived from or associated with the integument. They illustrate protection and environmental adaptation.
Choose an option to check your answer.
A.
Mechanical defense
B.
Endocrine feedback organ
C.
Blood pump
D.
Photosynthetic surface
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Correct Answer: A. Mechanical defense
Explanation:
A shell provides physical protection for soft tissues. Withdrawal into the shell reduces exposure to predators and environmental stress.
Choose an option to check your answer.
A.
Baroreceptor
B.
Phonoreceptor
C.
Chemoreceptor
D.
Photoreceptor
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Correct Answer: A. Baroreceptor
Explanation:
Baroreceptors detect pressure or stretch in blood vessels. Their signals help regulate heart rate and vascular tone to maintain blood pressure.
Choose an option to check your answer.
A.
Walls of internal organs
B.
Feathers only
C.
External insect cuticle
D.
Epidermal scales only
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Correct Answer: A. Walls of internal organs
Explanation:
Smooth muscle occurs in walls of organs such as blood vessels and digestive tract. It supports involuntary movements rather than voluntary limb movement.
Choose an option to check your answer.
A.
Integumentary system
B.
Circulatory system
C.
Endocrine system
D.
Digestive system
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Correct Answer: A. Integumentary system
Explanation:
Feathers are specialized integumentary structures. Damage to feathers affects insulation, display, or flight surface, not the internal skeleton directly.
Choose an option to check your answer.
A.
Joints and muscle attachment points
B.
No muscles anywhere
C.
Only soft fluid cavities
D.
A four-chambered heart
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Correct Answer: A. Joints and muscle attachment points
Explanation:
Jointed areas in the exoskeleton and internal muscle attachments allow arthropods to move appendages rapidly and precisely.