The nucleolus, which is part of the cell nucleus, plays an important role in the production of ribosomes.

In physics, the study of the 'nucleus' at the center of an atom is important.

The cell nucleus holds genetic information.

The number of nuclear-armed countries is increasing worldwide.

There is a shortage of nuclear fuel.

His research focuses on the relationship between specific diseases and karyotypes.

The inner core of the Earth is mainly composed of iron and nickel.

He warned about the dangers of nuclear warheads.

Nuclear reactions are used for mass production of energy.

The inner core of the Earth is extremely hot and is mainly composed of iron and nickel.