Jackie Womack, age 8, of Visalia, Calif., for her question:

ARE DOGS REALLY SMART?

One hundred and twenty one varieties of purebred dogs are recognized by the American Kennel Club. A purebred is a dog whose father and mother belong to the same breed. When the ancestors of a purebred are known and registered, the dog is said to have a pedigree. There are six groups: sporting dogs, hounds, terriers, working dogs, toy dogs and nonsporting dogs.

Dogs were the first animals to be tamed by man. They are naturally friendly.

Dogs definitely have intelligence. They can be taught to obey commands and do many tricks.

Instinct and keen senses are combined with intelligence to make the dog a wonderful friend to man. For example, dogs can guard the home as well as herds of sheep or cattle. They can make excellent hunting companions. They can bring the barnyard animals in from the field at night and even attack wild beasts that might harm livestock.

Dogs developed strong instincts from their wild ancestors. Today instinct makes all dogs gobble their food as though they were keeping other animals from eating it first. And instinct also makes a dog turn around several times before lying down, in just about the same way that wild dogs trampled grass to make a sheltered bed.

During a puppy's first three weeks he knows nothing and needs only warmth and food. But in his fourth week of life the puppy can see, hear, smell and use his intelligence to learn. Between the fourth and seventh weeks of life the dog will respond to humans, and then up to the 12th week he will be able to learn simple commands.

An order such as "Let's go for a walk'' can quickly come to mean to a dog exactly what the words mean to the human saying them. This action is a display of a dog's intelligence.

Some dogs also have the power to reason, scientists say. Many are able to solve problems such as how to get food from a box by pressing the right lever.

For hundreds of years performing dogs have entertained audiences in circuses and theaters. A number of different collies have been smart enough to play the role of Lassie on television, just as many different German shepherds have played the role of Rin Tin Tin in the movies and on TV.

Some dogs combine intelligence and instincts to do many important jobs. In Belgium, for example, farmers use dogs to haul milk, vegetables and other produce in small carts. In the Arctic regions dogs pull sleds which serve as the only means of transportation in winter. And in some parts of the world dogs are smart enough to be used to carry loads which can weigh from 30 to 60 pounds.