A purine will always pair with a pyrimidine. Examples of purines are adenine (pairs with thymine or uracil) and guanine (pairs with cytosine). Examples of pyrimidines are thymine (pairs with adenine), uracil (pairs with adenine), and cytosine (pairs with guanine).
it is full of romance
Lines that are straight and parallel
Rice and Peaaaa!
a husband and wife
ear rings ear rings
Eiffel Tower
If a cat has 19 pairs of chromosomes, each gamete will have 19 single (not pairs) of chromosomes.
i.e
Just two examples: Human = two legs (one pair). Elephant = four legs (two pairs).
Two examples: an arrowhead or a kite.
7 and 11, 9 and 10