1. The young man likes to do the same things his father does. He’s a chip off the old block.
2. Now that Ralph has grown up, he and his father are as different as night and day. But when Ralph was younger, he was a chip off the old block.

Synonym: spitting image. The expression probably originates from the idea that a chip off a block of wood or stone, though smaller, has the same characteristics as the block itself. A chip off the old block usually refers to a likeness in character or personality.