One of the following is a process of transmission of hereditary characteristics by chromosomes

Analyze the question: We need the option that describes a process by which chromosomes pass hereditary characteristics from parents to offspring (transmission), not just a feature of chromosomes or genes.

Concept: Heredity is transmitted through gametes. Gametes are formed by meiosis, in which homologous chromosomes separate (segregate) and end up in four daughter cells, each with half the chromosome number (haploid). At fertilization, gametes fuse to restore the diploid number. This is how genetic material passes from one generation to the next.

Evaluate each option:

• A. Genes relating to the same character occupy identical locations on the chromosomes. This describes a structural feature (homologous chromosomes carry alleles at the same loci). It is a description of gene location, not a process of transmission.
• B. Separation of homologous chromosomes into four daughter cells. This is meiosis, a true process. Homologous chromosomes separate and are distributed into four haploid cells (gametes), which carry the hereditary information to the next generation. ✔
• C. Separation of gametes during fertilization. Fertilization is the fusion of gametes, not their separation. This is incorrect.
• D. Dictating the formation of a protein by a gene in a chromosome. This is gene expression (protein synthesis), which is how a trait is expressed, not how it is transmitted.

Exam tip: Remember the difference between the two ideas:

• Transmission means passing genes on, through meiosis and fertilization.
• Expression means the gene produces a trait, through protein synthesis.

If a question says "transmission" or "inheritance," think meiosis and gametes. If it says "expression," think proteins.