Mutations that cause achondroplasia exert an effect, which can be classified as:

Correct Answer: B

Rationale: Achondroplasia (FGFR3 mutation) is a gain-of-function mutation, increasing receptor activity.

Correct Answer: A

Rationale: NF1 is autosomal dominant. Without the figure, typical AD inheritance is assumed (affected in each generation).

Correct Answer: C

Rationale: Without a figure, 'Submetacentric' (C) is accepted as per the document. Rationale: Chromosomes are classified by centromere position. Metacentric has a central centromere, acrocentric has it near one end with a short p-arm, submetacentric is off-center, and telocentric has it at the end. 'Interphase chromosome' isn’t a structural type. Submetacentric is plausible for many human chromosomes (e.g., chromosome 1), making 'C' reasonable without context.

Correct Answer: D

Rationale: Telomeres consist of TTAGGG repeats throughout (D is true). Rationale: Telomerase uses an RNA template (not DNA, B false), extends the 3’ end (C misleading), and is active in cancer (A false). Activity decreases with age (E false). 'D' fits best.

Correct Answer: A

Rationale: Trisomy 21 (Down syndrome, A) matches these features. Rationale: Flat face, short neck, hypotonia, etc., are classic Down syndrome signs. Monosomy X (Turner) and Trisomy X have different phenotypes (e.g., short stature vs. subtle effects).