Q 01/05

DNA is shaped like a twisted ladder, a form known by what name?

A) A double helix

B) A Möbius strip

C) A triple spiral

D) A figure eight

Answer · why

A) A double helix

A double helix. Its two strands can unzip down the middle, and each half then serves as the pattern for rebuilding its partner, which is how a cell co...

Q 02/05

DNA comparisons show which ape is, alongside the bonobo, the closest living relative of humans?

A) Gorilla

B) Orangutan

C) Chimpanzee

D) Gibbon

Answer · why

C) Chimpanzee

Chimpanzee. That does not mean people evolved from chimps: the two lines branched from a shared ancestor millions of years ago, and each has kept chan...

Q 03/05

In DNA, the letter A always pairs with which letter?

A) C

B) G

C) T

D) U

Answer · why

C) T

T, short for thymine. Cells proof-read these pairings as they copy DNA: when the wrong letter slips in opposite an A, repair proteins spot the mismatc...

Q 04/05

What do the letters DNA stand for?

A) Double nucleus atom

B) Dextrose nucleic acid

C) Deoxyribonucleic acid

D) Dual nitrogen acid

Answer · why

C) Deoxyribonucleic acid

Deoxyribonucleic acid. For decades scientists thought it a dull structural chemical and expected proteins to carry inherited traits, until experiments...

Q 05/05

The two side rails of the DNA ladder are built from phosphate and which other ingredient?

A) Salt

B) Sugar

C) Fat

D) Protein

Answer · why

B) Sugar

Sugar. DNA's sugar has one oxygen atom fewer than the sugar in its cousin RNA, and that small gap makes DNA the sturdier of the two, fit to store inst...