Inheritance Inheritance. Metachromatic leukodystrophy is inherited in an autosomal recessive manner. This means that both copies of the disease-causing gene in each cell must have a mutation for an individual to be affected. Individuals inherit two copies of each gene - one copy from each parent.
Crown-of-thorns starfish. Crown-of-thorns starfish are one of the most damaging creatures of tropical coral reefs, particularly Australia's Great Barrier Reef. They are voracious predators that release the contents of their stomach on to the coral.
The interconnected nature of the Great Barrier Reef may make it more vulnerable to the crown-of-thorns than other reefs, as it means they can spread easily. It is estimated that more than one in three reefs on the Great Barrier Reef have been affected by the crown-of-thorns starfish over the past 60 years.