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90 questions in this collection · Page 1 of 9
The Living World
Biological Classification
AI-generated explanation. Check against your textbook.
The incorrect statement is option 2. In NCERT, the infective part of a virus is its nucleic acid (DNA or RNA), not the protein coat. The protein coat (capsid) encases the nucleic acid but is not itself the genetic material. Hence, viruses are obligate parasites that need a host to reproduce. Viroids lack a protein coat, and prions are infectious proteins with no nucleic acid, consisting only of abnormally folded proteins.
NCERT emphasizes that the key infectious nature of viruses lies in their nucleic acid, while prions are misfolded proteins and viroids are naked RNA without a capsid.
Viruses have nucleic acid enclosed in a protein coat; infective material is nucleic acid.
Animal Kingdom
| (A)Pila | (I)Flame cells |
| (B)Bombyx | (II)Comb plates |
| (C)Pleurobrachia | (III)Radula |
| (D)Taenia | (IV)Malpighian tubules |
Animal Kingdom
AI-generated explanation. Check against your textbook.
The correct option is 2: Annelida, Arthropoda and Chordata. All three groups show organ system level of organisation and bilateral symmetry. They are true coelomates and exhibit body segmentation (Annelida and Arthropoda are clearly segmented;Chordata shows segmentation in its body plan, such as somites in many groups). Thus they possess all the features listed: organ-system level, bilateral symmetry, and true coelomate with segmentation.
While Mollusca are bilaterally symmetrical and coelomate with organ systems, they are not typically described as having true body segmentation like Annelids or Arthropods in the NCERT context.
Organ system level, bilateral symmetry, and true coelom with segmentation are characteristic of Annelida and Arthropoda; Chordata also shows segmentation in its body plan.
Morphology Of Flowering Plants
Morphology Of Flowering Plants
AI-generated explanation. Check against your textbook.
Persistent nucellus in the seed is called perisperm. In some seeds, the nucellus remains as a food reserve and forms the main part of the seed’s nutritive tissue, instead of developing into endosperm.
Perisperm is seen in seeds of some plants like certain types of peppers and black pepper, where the nucellus does not degenerate.
Persistent nucellus = perisperm; chalaza, hilum, and tegmen refer to other parts: chalaza (attachment region), hilum (seed scar), tegmen (outer seed coat layer).
Anatomy Of Flowering Plants
AI-generated explanation. Check against your textbook.
Annual rings are formed due to seasonal variation in wood, with spring wood (light, spacious vessels) and autumn wood (darker, dense vessels) produced within one year. The cambium’s differential activity creates these light and dark bands. In temperate regions, distinct rings are visible because seasons differ markedly; in tropical regions, rings may be faint or absent due to less pronounced seasonality. Statement 3 says rings are not prominent in temperate region, which is not true. Therefore option 3 is the incorrect statement.
In NCERT books, annual rings are used to estimate the age of a tree and study past climatic conditions.
Annual rings result from cambial activity varying with seasons; they are prominent in temperate regions where seasons differ.
Structural Organisation In Animals
AI-generated explanation. Check against your textbook.
Ciliated epithelial cells help move mucus or particles in a fixed direction. In humans, these ciliated cells line the bronchioles, helping clear inhaled dust, and the Fallopian tubes, helping move the egg towards the uterus. Thus, option 1 (Bronchioles and Fallopian tubes) is correct according to NCERT concepts about ciliated lining in these organs.
In the respiratory tract, cilia beat together to push mucus upward toward the throat, a process called mucociliary clearance.
Ciliated epithelium is present in the Fallopian tubes and in the bronchi/bronchioles, aiding movement of cells or mucus in a specific direction.
Structural Organisation In Animals
Cell The Unit Of Life