Class 10/Specimen Paper
Created by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
BioNotesBioNotesCreated by Titas Mallick
Biology Teacher • M.Sc. Botany • B.Ed. • CTET (CBSE) • CISCE Examiner
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ICSE Suggested Specimen Paper Based Preparation Guide
During which phase of the cell cycle would you expect to see chromosomes in their most condensed state? Why is this condensation necessary?
A scientist discovers a new species. They find that its DNA contains 20% Guanine. What are the percentages of the other three bases (Adenine, Thymine, Cytosine)?
Odd One Out: Autosome, Sex Chromosome, Chromatid, Homologous Chromosome.
Scenario: If the telomeres of a chromosome were to be damaged or shortened, what would be the likely consequence for the cell over several generations of division?
Down Syndrome: A Chromosomal Abnormality
Down syndrome, also known as Trisomy 21, is a genetic condition caused by the presence of a full or partial extra copy of chromosome 21. This is an example of an aneuploidy, where there is an abnormal number of chromosomes. The extra genetic material disrupts the normal course of development, leading to the characteristic physical features and intellectual disabilities associated with Down syndrome. This case highlights the critical importance of having the correct number of chromosomes for normal human development and shows that even a single extra autosome can have profound effects.
Assertion (A): In humans, a male has an XY pair of sex chromosomes. Reason (R): The Y chromosome carries the gene that determines maleness.
(a) Both (A) and (R) are true and (R) is the correct explanation of (A). (b) Both (A) and (R) are true but (R) is not the correct explanation of (A). (c) (A) is true but (R) is false. (d) (A) is false but (R) is true.
Euchromatin is described as "transcriptionally active" while heterochromatin is "transcriptionally inactive." Based on your understanding of chromosome compaction, provide a structural explanation for this difference in activity.