I believe the correct answer is DDT.
It kills mosquitoes but thins the eggs of birds.
Hope this helps.
an egg cell has a haploid nucleus so it has half the number of dna because it fuses with a sperm cell to have the full amount of dna.
an egg cell has 23 chromosomes and a sperm cell has 23 chromosomes.
they both have half the amount of dna to form a zygote
