Final answer:
A gamete contains only one copy of each chromosome type due to the segregation of homologous chromosomes during meiosis, which corresponds directly with Mendel's law of segregation.
Step-by-step explanation:
Understanding Mendel's Law of Segregation
The behavior of chromosomes during meiosis explains Mendel's law of segregation. Specifically, a gamete contains only one copy of each type of chromosome because of the segregation of homologous chromosomes. During meiosis, especially during the first division (meiosis I), homologous chromosomes are separated into different gametes. This ensures that each gamete has just one allele for each trait. Independent assortment and crossing over also occur during meiosis, contributing to genetic diversity, while random fertilization ensures that any sperm can fuse with any egg, further increasing variation among offspring. However, it is the segregation of the homologous chromosomes that directly corresponds with Mendel's law of segregation, guaranteeing that gametes contain only one copy of each gene.