Home / iGCSE Biology (0610)-17.1 Chromosomes, genes and proteins – iGCSE Style Questions Paper 1

iGCSE Biology (0610)-17.1 Chromosomes, genes and proteins – iGCSE Style Questions Paper 1

Question

What describes an allele?

A) an alternative form of a chromosome made of DNA
B) an alternative form of a chromosome made of protein
C) an alternative form of a gene made of DNA
D) an alternative form of a gene made of protein

▶️ Answer/Explanation
Solution

Ans: C

An allele is defined as an alternative form of a gene that arises by mutation and occupies the same locus on a chromosome. Genes are segments of DNA, not protein.

Options A and B incorrectly describe alleles as forms of chromosomes, while D inaccurately states alleles are made of protein. Only C correctly identifies alleles as DNA-based gene variants.

Question

What are alleles made of?

A) amino acids
B) DNA
C) genes
D) protein

▶️ Answer/Explanation
Solution

Ans: B

Alleles are different versions of the same gene that determine variations in inherited characteristics. They are composed of DNA (B), the genetic material that carries instructions for protein synthesis. While genes (C) are segments of DNA, alleles specifically refer to alternative forms of a gene. Amino acids (A) and proteins (D) are products of gene expression, not the alleles themselves.

Scroll to Top