A diploid cell which has $8$ chromosomes undergoes meiosis and produces $4$ daughter cells. What is the number of chromosomes present in each daughter cell formed at the end of meiosis-I?

Meiosis-I is a reductional division where homologous chromosomes separate, reducing the chromosome number to half in the resulting daughter cells.

The original diploid cell has $2n = 8$ chromosomes.

At the end of meiosis-I, the daughter cells become haploid ($n$).

Therefore, the number of chromosomes in each daughter cell is $n = \dfrac{8}{2} = 4$ chromosomes.

Answer: $4$ chromosomes