Final answer:
If sperm and egg cells were normally diploid, their fusion would create a polyploid zygote with developmental issues, risking the viability and genetic diversity of future generations.
Step-by-step explanation:
Consequence of Diploid Sperm and Egg Cells
If sperm and egg cells were normally diploid, each fusion during fertilization would result in a zygote with twice the normal number of chromosomes, leading to a condition called polyploidy. Organisms with this condition can have severe developmental issues, as the genome is not balanced.
The resulting cell would not undergo normal embryonic development, and future generations of cells would possibly become nonviable. The balance of maternal and paternal genes, essential for development, would be disturbed, potentially giving rise to a myriad of genetic abnormalities and reducing genetic diversity.
In typical sexual reproduction, haploid gametes (sperm and egg cells) each carry a single set of chromosomes. Through fertilization, they fuse to form a diploid zygote, restoring the full chromosomal set for the species. Diploidy is crucial for maintaining the stable transmission of genetic material across generations, ensuring species continuity and reproductive success.
For example, the increased number of chromosomes could lead to genetic abnormalities, developmental defects, and infertility. Additionally, the increased ploidy could disrupt the normal balance of gene expression and gene regulation, leading to further physiological consequences.