The answers would be 24 and fertilises.
Pollen is the male gamete of lily, which is a haploid cell, with only half the chromosomes of the normal diploid ones. Therefore, if the haploid gamete has 12 chromosomes, so the diploid would be 12+12 which makes 24.
The egg is also a gamete of lily, but it's a female gamete. It is also a haploid cell, with only 12 chromosomes which is given in the question. So, when the sperm fuses and fertilises the egg, the zygote would have 24 chromosomes which is formed by 2 haploid gametes.
The urinary system consists of the kidneys, the ureters, the urinary bladder, and the urethra.
The answer to your question is called terminal velocity.
Even a large tapeworm cannot be seen with the naked eye and is therefore still within the realm of microbiology
