Which of the following statements about inclusion
bodies is incorrect ?
AI-generated explanation. Check against your textbook.
Explanation:
Inclusion bodies are reserve materials (like glycogen, lipids, pigments) that lie free in the cytoplasm and are not bounded by a membrane. They do not participate in the ingestion of food particles. Therefore, statement 2 is incorrect.
🧠 Did You Know?
NCERT describes inclusion bodies as reserve deposits in the cytoplasm, formed when resources are stored for later use.
💡 NCERT Memory Line:
Inclusion bodies: reserve materials in the cytoplasm, often not membrane-bound.
Which of the following pairs is of unicellular
algae?
AI-generated explanation. Check against your textbook.
Explanation:
Chlorella and Spirulina are considered unicellular organisms in NCERT. Chlorella is a simple, single-celled green alga. Spirulina is described as a blue-green alga (cyanobacterium) and, for the purposes of NCERT multiple-choice questions, treated as unicellular. Thus, this pair represents unicellular algae.
? Did You Know?
Other options include multicellular forms: Laminaria and Sargassum (brown algae), Gelidium and Gracilaria (red algae), and Anabaena (cyanobacterium) with Volvox (colonial green alga), not unicellular.
? NCERT Memory Line:
Unicellular green algae like Chlorella, and unicellular blue-green algae (spirulina) are examples used to illustrate single-celled photosynthetic organisms in NCERT discussions.
Which of the following statements are true for
the phylum-Chordata?
(A) In Urochordata notochord extends from head to tail and it is present throughout their life.
(B) In Vertebrata notochord is present during the embryonic period only.
(C) Central nervous system is dorsal and hollow.
(D) Chordata is divided into 3 subphyla : Hemichordata, Tunicata and Cephalochordata.
AI-generated explanation. Check against your textbook.
Explanation:
Correct answer: (B) and (C). In Urochordata (tunicates), the notochord is present only in the larval stage and is not extended throughout life, so statement (A) is false. In Vertebrata, the notochord is present during embryonic development but is typically replaced by the vertebral column, so statement (B) is true. The central nervous system in Chordata is dorsal and hollow (a dorsal nerve cord), so statement (C) is true. Chordata is divided into three subphyla: Cephalochordata, Urochordata (Tunicata), and Vertebrata; Hemichordata is a separate phylum, not a subphylum, so statement (D) is false. Therefore, (B) and (C) are true.
🧠 Did You Know?
The dorsal hollow nerve cord is a key hallmark of Chordata, visible in embryos and some larval stages across subphyla.
💡 NCERT Memory Line:
Notochord is a defining chordate feature; in Vertebrata it is typically replaced by the vertebral column during development.
AI-generated explanation. Check against your textbook.
Explanation:
Option 3 is incorrect. In a woody stem, sapwood is the outer, younger part of secondary xylem that conducts water and minerals from roots to leaves. It is not the innermost part; the innermost secondary xylem is heartwood. Heartwood is darker due to deposits like tannins, resins, and essential oils and it provides mechanical support.
🧠 Did You Know?
In NCERT, sapwood is described as the conducting region for water, while heartwood is non-conducting but structurally important and often darker in color.
💡 NCERT Memory Line:
“Sapwood conducts water; heartwood is non-conducting and darker due to deposits.”
AI-generated explanation. Check against your textbook.
Explanation:
In NCERT, half-inferior (also called half-embedded) ovary means the ovary is partly below the point of attachment. Plum (Prunus) shows this condition, so the ovary is half-inferior. Thus option 4 is correct.
🧠 Did You Know?
Ovary position helps categorize flowers as superior, half-inferior, or inferior, affecting fruit development and floral structure.
💡 NCERT Memory Line:
Ovary position is a key feature in identifying different fruit types; plum is an example of half-inferior ovary as per NCERT explanations.