Write the functions of each of the following parts of a neurone :
(a) Dendron
(b) Axon
(c) Myelin Sheath
(d) Schwann Cell
(e) Node of Ranvier
OR
Write the functions of the following structural parts of a eukaryotic chromosome:
(a) Centromere
(b) Nucleolar Organizer
(c) Chromatid
(d) Telomere
(e) Kinetochore
Functions of Parts of a Neurone
| Part | Function |
|---|---|
| Dendron | Receives impulses from other cells and conveys them toward the cell body. |
| Axon | Transmits nerve impulses away from the cell body to other neurons or muscles. |
| Myelin Sheath | Insulates the axon and increases the speed of nerve impulse transmission. |
| Schwann Cell | Forms the myelin sheath around axons in the peripheral nervous system. |
| Node of Ranvier | Gaps in myelin sheath that facilitate rapid conduction of nerve impulses. |
Or
Functions of Parts of a Eukaryotic Chromosome
| Part | Function |
|---|---|
| Centromere | Joins the two sister chromatids and helps in chromosome movement during cell division. |
| Nucleolar Organizer | Contains genes for ribosomal RNA (rRNA) and is involved in ribosome formation. |
| Chromatid | Each of the two thread-like strands into which a chromosome divides during cell division, each contains a double helix of DNA. |
| Telomere | Protects the ends of chromosomes from deterioration or from fusion with neighboring chromosomes. |
| Kinetochore | Protein structure on the centromere where spindle fibers attach during cell division. |
More WBBSE Easy level questions
Draw a scientific diagram of a neurone and label the following parts — Axon Node of Ranvier Dendron Schwann Cell OR Draw a scientific diagram of the morphological structure of a eukaryotic chromosome and label the following parts — Chromatid Telomere Centromere Nucleolar Organizer
Write one function each of ribosome and lysosome.
Which cell organelle is termed as “power house” of cell?
In which phase of Interphase are the proteins essential for the formation of spindle fibres synthesized?
What happens if the functions of checkpoints in the cell cycle get hampered?
A pair of related terms is given below. On the basis of the relationship in the first pair write the suitable word in the gap of the second pair. Purine : Adenine : : Pyrimidine : ____
Each nucleoside contains a nitrogenous base and phosphoric acid.
Select the correct pair in the case of humans: (a) Normal pattern of chromosome of ovum — 22A + XX (b) Normal pattern of chromosome of ovum — 22A + Y (c) Normal pattern of chromosome of ovum — 22A + X (d) Normal pattern of chromosome of ovum — 22A + XY
The name of the terminal parts of the Chromosome is — (a) Centromere (b) Telomere (c) Nucleolar Organizer (d) Satellite
Select the correct pair — (a) Telophase — Movement of daughter chromosomes towards poles (b) Telophase — Disappearance of Nuclear Membrane and Nucleolus (c) Telophase — Formation of spindle fibre (d) Telophase — Reappearance of Nuclear Membrane and Nucleolus
Draw a scientific diagram of the vertical section of a human eyeball and label the following parts: [3+2=5] (a) Choroid (b) Lens (c) Cornea (d) Vitreous humour OR Draw a scientific diagram of the anaphase stage of mitotic cell division in an animal cell and label the following parts- [3+2=5] (a) Centromere (b) Daughter chromosome (c) Polar region (d) Spindle fibre
Distinguish between Mitosis and Meiosis on the basis of the following three aspects Site of occurrence Nature of division of chromosome Number of cells produced Explain the following phenomena related to meiotic cell division Separation of chromosome and chromatid Crossing over Or Distinguish between the cytokinesis of plant cells with the cytokinesis of animal cells on the basis of the following aspects : Process Time of initiation Role of Golgi bodies Establish the interrelationships among genes, DNA and chromosome.
