Which of the following statements pertaining to arthropod exoskeletons is false?
Show answer Hide answer
Answer: B. It contains joints, for the same purpose as present in human skeletal system
Explanation
Arthropod exoskeletons are rigid cuticles lacking articulated vertebrate-like synovial joints. Instead of true joints, they feature thin flexible zones allowing localized bending. Rigid chitinous armor requires special structural adaptations to permit animal movement. Exoskeletons provide robust protection and muscle attachment points for invertebrates. Chitin impregnated with proteins forms a tough external protective shell. Molting is necessary because rigid exoskeletons cannot expand as the animal grows.
Insects and crustaceans rely on flexible cuticular hinges for rapid locomotion. Biomechanics researchers study arthropod joints to design flexible robotic articulation. Understanding exoskeleton limits explains why arthropods must undergo periodic shedding phases. Exoskeletons permit gaseous exchange through specialized tracheal systems or book lungs. Internal muscles attach directly to the inner surface of the rigid exoskeleton. Arthropod exoskeletons possess sensory hairs and slit sensilla capable of detecting stimuli.
Related questions
Q1. Which of the following assertions about conifers is accurate?
Show answer Hide answer
Answer: D. Excrete some of the waste materials directly into soil, occasionally using them as a chemical weapon against other competing plants.
Conifers actively secrete metabolic wastes and secondary compounds directly into surrounding soils. These root exudates often function as chemical weapons inhibiting neighboring plant competitors. Allelopathy allows coni...
Q2. Which of the following illustrates osmoregulatory mechanisms employed by hydrophytes?
Show answer Hide answer
Answer: A. Increases transpiration by increasing the surface area of the leave.
Hydrophytes often increase transpiration by maximizing leaf surface area in wet environments. Abundant water availability allows these plants to shed excess moisture continuously. Broad flat leaves enhance water loss and...
Q3. Which of the following biological associations does NOT qualify as an example of symbiosis?
Show answer Hide answer
Answer: B. Marchantia sporophyte and gametophyte
The Marchantia sporophyte depends entirely on its gametophyte for nutrition and physical support. This intimate maternal dependency resembles a parasitic relationship rather than mutual symbiosis. Nutrients flow from the...
Q4. Which of the statements regarding the alternation of generations in bryophytes is incorrect?
Show answer Hide answer
Answer: C. Both the gametophyte and sporophytes are haploid generations thus can produce haploids gametes to continue the diploid number on fertilization
Bryophyte gametophytes are haploid while sporophytes are diploid generations. Claiming both generations are haploid ignores the diploid chromosome number of the sporophyte. Meiosis occurs within the diploid sporophyte ca...
Q5. Which statement regarding filicinae, a subgroup of tracheophytes, is false_________________?
Show answer Hide answer
Answer: A. They belong to sphenopsida
Filicinae ferns belong to the class Pteropsida rather than the Sphenopsida group. Ferns feature large megaphyll leaves known as fronds with complex branching veins. Taxonomic classification places true ferns firmly withi...
Q6. Which assertion regarding ciliates is erroneous_____________?
Show answer Hide answer
Answer: D. Diploid nucleus being smaller is responsible for cells metabolism and growth while polyploidy nucleus functions in sexual process.
In ciliates, the large macronucleus governs everyday cellular metabolism and growth. The small micronucleus handles genetic exchange during sexual reproduction processes. Reversing the functions of macro and micronuclei...