Final answer:
The statement about a merodiploid being a haploid organism with a second copy of a part of its genome is false. A merodiploid is a bacterium that has two copies of a particular gene. Diploid organisms, such as most animals and plants, have two sets of chromosomes, and during prophase II of meiosis, the cells are haploid with one copy of each gene.
Step-by-step explanation:
A merodiploid is not a haploid organism; therefore, the correct statement is false. A merodiploid is a bacterium that has two copies of a particular gene, where one copy is on the chromosome and the other on an extra-chromosomal element like a plasmid. This condition differs from a true haploid, which has only one set of genes.
In contrast, diploid organisms, such as most animals and plants, contain two sets of chromosomes: one set inherited from each parent. These organisms typically have two copies of each gene, one on each homologous chromosome. In the lifecycle of diploid-dominant organisms, the multicellular stage is prevalent, and the creation of haploid cells, namely, gametes, occurs through meiosis. An individual with the correct number of chromosomes for their species is termed euploid.
During meiosis, particularly in prophase II, the cells are haploid, each containing one copy of each gene. This is because meiosis I reduces the chromosome number from diploid to haploid by separating the homologous chromosomes, and meiosis II separates the sister chromatids, similar to mitosis, without changing the chromosome number.