Jean Breedlove, age 11, of Mesa, Ariz., for her question:

WHEN DOES LAMB BECOME MUTTON?

Lamb is the flesh of young sheep which are also called lambs. The flesh of older sheep is called mutton. Lamb becomes mutton when the sheep is about one year old.

Lamb has a much more delicate flavor than mutton, and it is also more tender.

The meatpacking industry makes the test for lamb by the appearance of the "break joint" where the forefeet are removed from the slaughtered animal. In lambs less then one year old, the break joint has well defined ridges which are moist and smooth. As the lamb grows older, the tissue in the area becomes dry and hard.

People in the United States average only about three pounds of lamb per person in a year. On the other hand, the people in Australia eat about 38 pounds of lamb per person every year.

Europeans prefer mutton to lamb, but Americans definitely prefer the more delicate flavor of lamb. About 90 percent of the sheep marketed in the United States each year are lambs.