Q 01/05

Roughly how many neurons does the human brain contain?

A) 8.6 billion

B) 86 billion

C) 860 billion

D) 8.6 trillion

Answer · why

B) 86 billion

86 billion. Textbooks long quoted a round 100 billion, plus ten times as many support cells, until a 2009 count found about 86 billion neurons and rou...

Q 02/05

About what share of the body's energy does the brain consume?

A) 2%

B) 5%

C) 20%

D) 50%

Answer · why

C) 20%

20%, more than any other organ uses. Aristotle had it backwards: he placed thought in the heart and took the brain for a device to cool the blood.

Q 03/05

About how much does an adult human brain weigh?

A) 150 grams

B) 450 grams

C) 1.4 kilograms

D) 4.5 kilograms

Answer · why

C) 1.4 kilograms

1.4 kilograms, or about three pounds. Weight says little about ability: Albert Einstein's brain, weighed after his death in 1955, was on the small sid...

Q 04/05

A neurosurgeon's well-known comparison likens the feel of a living brain to which food?

A) Hard cheese

B) Cold butter

C) Ripe banana

D) Soft tofu

Answer · why

D) Soft tofu

Soft tofu, the choice of neurosurgeon Katrina Firlik. Some of her colleagues say toothpaste, but she finds that too runny: a cube cut from a living br...

Q 05/05

Which three main parts make up the human brain?

A) Cerebrum, brainstem and cerebellum

B) Cortex, thalamus and spine

C) Left brain, right brain and spinal cord

D) Grey matter, white matter and fluid

Answer · why

A) Cerebrum, brainstem and cerebellum

Cerebrum, brainstem and cerebellum. The wrinkled cerebrum does the thinking, the brainstem keeps breathing and heartbeat going, and the cerebellum is ...