Q 01/05

Charles Darwin's last scientific book, in 1881, argued that which animals create the fertile top layer of soil?

A) Termites

B) Dung beetles

C) Earthworms

D) Woodlice

Answer · why

C) Earthworms

Earthworms intrigued Darwin so much that he made an excursion to Stonehenge to see how its monoliths had been buried by their castings. The book sold ...

Q 02/05

Which disease, popularly blamed on rusty nails, is caused by bacteria whose spores live in soil and manure?

A) Tetanus

B) Cholera

C) Rabies

D) Typhoid

Answer · why

A) Tetanus

Tetanus comes from Clostridium tetani, and rust itself is harmless. A dirty nail simply punctures the skin and carries the soil-dwelling spores deep i...

Q 03/05

What name did two Australian scientists coin in 1964 for the earthy smell of rain falling on dry soil?

A) Ozone

B) Miasma

C) Effluvium

D) Petrichor

Answer · why

D) Petrichor

Petrichor joins the Greek word for stone with ichor, the golden fluid said to run in the veins of the Greek gods. Before 1964 the scent was known as a...

Q 04/05

Many hydrangeas act as natural soil testers, producing flowers of which color when the ground is acidic?

A) Pink

B) Blue

C) White

D) Yellow

Answer · why

B) Blue

Blue flowers appear because acidic soil makes aluminum ions available for the shrub to absorb, while alkaline ground turns the same plant pink.

Q 05/05

Which Italian landmark began tilting during its 12th-century construction because the ground beneath was too soft?

A) Tower of Pisa

B) Giotto's Campanile

C) Torre del Mangia

D) St Mark's Campanile

Answer · why

A) Tower of Pisa

Tower of Pisa builders had only reached the second floor when it began to sink in 1178. Engineers finally steadied it between 1993 and 2001, trimming ...