Which allele combination represents a female who is a carrier for an X-linked recessive disorder?

The probability of producing a normal child by two parents who are carriers for an autosomal recessive disorder is

The transport tubes for food coming down the plants are called?

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population.b) the separated population is small, and genetic drift occurs.c) the isolated population is exposed to different selection pressures than the ancestral population.d) different mutations begin to distinguish the gene pools of the separated populations.e) gene flow between the two populations is extensive.