In fruit flies, the recessive pr and cn mutations cause brown and bright-red eyes, respectively (wild-type flies have brick-red eyes). The double mutant pr-cn combination has orange eyes. An F1 female who is wild-type is crossed to an orange-eyed male. Their F2 progeny have the following distributions: Phenotype Observed

Wild-type 8
Brown 241
Bright-red 239
Orange 12
500

The F1 mother of these progeny (F2) resulted from a cross between two flies from true breeding lines (P generation). What are the genotypes of these two lines?

a. pr cn/prcn and prcn/prcn
b. prtcn/prcn and pr cn /prcn
c. prtan lpr cn and prcn/prcn
d. pren /prcn and pr cn/prcn

answer: "circumcision is a common procedure in which the skin covering the tip of the penis is surgically removed."

micro/nanoscale topography surface exhibits many prominent properties and is extensively employed in biomedical device, microfluidic device and energy device fabrication. additionally, the clinical applications of biomaterials can be largely expanded with of nanostructured surfaces.

by drinking easy

very easy

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.