Exams › NEET › Biology › Structural Organisation in Animals
91 questions with worked solutions.
Q1. Stratum germinativum is an example of which kind of epithelium?
Answer: Cuboidal
The stratum germinativum (basal layer) contains mitotically active cells that are typically cuboidal to low columnar in shape. Since the question asks for the epithelial kind and the correct option given is cuboidal, that is the best match among the choices.
Q2. During regeneration, modification of an organ to other organ is known as
Answer: Morphallaxis
Morphallaxis is regeneration in which remaining tissues reorganize and transform to form a different structure or restore form. It differs from epimorphosis, which mainly involves new growth from a blastema, and from general morphogenesis or accretionary growth.
Answer: epidermis
Ecdysis means molting or shedding the outer body covering. In this question, the correct choice is epidermis because it is the skin layer that is shed during this process.
Q4. Pheretima posthuma is highly useful as
Answer: they make the soil porous, leave their castings and take organic debris in the soil
Pheretima posthuma is an earthworm that benefits soil by burrowing, which increases porosity and aeration. Its castings enrich the soil, and it helps incorporate organic debris, improving fertility.
Answer: red with haemoglobin in plasma
Pheretima (earthworm) has haemoglobin dissolved in the plasma rather than inside blood cells. Because haemoglobin is the red respiratory pigment, its blood appears red.
Q6. Earthworms are
Answer: more useful than harmful
Earthworms improve soil structure, aeration, and nutrient cycling, which helps plants grow. Their overall impact is beneficial, so they are considered more useful than harmful.
Q7. Photoreceptors of earthworm occur on
Answer: dorsal surface
Earthworms have photoreceptor cells on the dorsal surface, which helps them sense light and avoid exposure. This placement is useful because the top side is the first to receive light when they come near the soil surface.
Q8. Frogs differ from humans in possessing:
Answer: nucleated red blood cells
Frogs, like other non-mammalian vertebrates, have red blood cells that retain nuclei. Human red blood cells lose their nuclei during maturation, so this is a key difference.
Q9. If the head of cockroach is removed, it may live for few days because
Answer: the head holds a small proportion of a nervous system while the rest is situated along the ventral part of its body.
A cockroach can survive briefly without its head because only a small part of its nervous system is in the head. The major nerve cord and ganglia are located along the ventral side, so many basic functions can continue for some time.
Q10. Which one of the following is the true description about an animal concerned?
Answer: Cockroach - 10 pairs of spiracles (2 pairs on thorax and 8 pairs on abdomen)
Cockroach has 10 pairs of spiracles: 2 pairs on the thorax and 8 pairs on the abdomen. The other statements are inaccurate because earthworm’s digestive parts are not listed in the correct order, frog body is not divided into three regions, and in rat the right kidney is slightly higher than the left.
Q11. Functionwise, just as there are nephridia in an earthworm, so are
Answer: flame cells in liver fluke
Nephridia are excretory structures in earthworms. Flame cells in liver fluke are also excretory/osmoregulatory structures, so they are functionally analogous. The other options are sensory, secretory, or muscular structures, not excretory ones.
Q12. Mucus helps frog in forming
Answer: moist skin
Frog skin must stay wet for gas exchange and to prevent dehydration. Mucus secreted by the skin maintains that wet, moist condition.
Q13. Tracheae of cockroach and mammal are similar in having
Answer: noncollapsible walls
Cockroach tracheae and mammalian airways both need to stay open for gas exchange, so they have structural support that prevents collapse. Cilia are not a feature of cockroach tracheae, and the other options do not describe a shared property.
Q14. Skin is a respiratory organ in
Answer: frog
Frogs can perform cutaneous respiration, meaning oxygen and carbon dioxide diffuse directly through their moist skin. This is especially important in amphibians, unlike birds, lizards, and mammals, whose skin is not a major respiratory surface.
Answer: Rana tigrina
The bull frog of India is commonly identified as Rana tigrina in standard zoological nomenclature. The other options refer to different species or are incorrect spellings.
Q16. The ciliated columnar epithelial cells in humans are known to occur in:
Answer: bronchioles and fallopian tubes
Ciliated columnar epithelium is adapted for moving mucus or ova by coordinated ciliary beating. In humans, it is found in bronchioles and fallopian tubes, where that transport function is essential.
Q17. The kind of epithelium which forms the inner walls of blood vessels is:
Answer: squamous epithelium
The inner lining of blood vessels is endothelium, which is made of simple squamous epithelium. Its thin, flat cells reduce friction and allow efficient diffusion across the vessel wall.
Q18. Cuboidal epithelium with brush border of microvilli is found in
Answer: Proximal convoluted tubule of nephron
The proximal convoluted tubule is lined by simple cuboidal epithelium with a prominent brush border of microvilli to greatly increase surface area for reabsorption. This feature is characteristic of renal tubules, not ducts, airway passages, or intestinal lining.
Q19. The epithelial tissue present on the inner surface of bronchioles and fallopian tube is:
Answer: ciliated
The inner lining of bronchioles and fallopian tubes is ciliated epithelium, which helps move mucus in the airways and the ovum in the reproductive tract. This coordinated movement is a key function of cilia.
Q20. The cell junctions called tight, adhering and gap junctions are found in
Answer: epithelial tissue
Tight, adhering, and gap junctions are characteristic of epithelial cells because epithelia form closely packed sheets that need sealing, attachment, and intercellular communication. Connective, neural, and muscular tissues do not typically feature all three junction types as defining structures.