In 1999,researchers found that they could create hybrid embryos between two species of sea urchin that had been separated for 10 million years.By treating eggs to remove the jelly coat,the sperm of the other species was able to fertilize.What step of the fertilization process is normally blocked,preventing hybridization between these species?
A)Sperm penetration
B)Membrane fusion
C)Egg activation
D)Nuclear fusion

Question

Quizplus · Accepted Answer

The jelly coat surrounding the egg normally blocks sperm penetration and prevents hybridization between these species. However, by removing the jelly coat, the sperm of the other species was able to penetrate and fertilize the egg. Membrane fusion, egg activation, and nuclear fusion are all steps that occur after sperm penetration and would not be affected by the jelly coat barrier.

In 1999,researchers Found That They Could Create Hybrid Embryos Between