The curling direction in snails is delayed a generation in its expression. the offspring of a snail are phenotypically the phenotype dictated by the genotype of the mother. dextral curling (shell opens to the right) is dominant to sinistral curling (shell opens to the left). a cross between a homozygous sinistral female snail and a homozygous dextral male resulted in a sinistral female. if this f1 sinistral female is crossed to a homozygous sinistral male, what progeny phenotypes are expected? "

and  Explanation:

coiling in snails is due to maternal effect genotype of the mother determines the phenotype of the offspring. F1 sinistral female is heterozygous let the alleles be D-dextral, d-sinistral so her genotype is Dd, so she can produce mRNA for both D and d alleles so both these mRNAs cn move into the egg, the egg can be either D or d but the egg contains mRNA of D allele so the egg hen fertilized by d sperm from homozygous sinistral male develops into dextral coiling offspring since the eggs from hich these snails developed had mRNA of allele D. so the answer is all dextral

meteorologists would compare a new weather map with one 24 h old to see how fast a front is moving.