Where does new primary growth occur on a winter twig?

New primary growth on a winter twig occurs at the apical meristem, which is located at the tip of the twig. This region contains actively dividing cells that contribute to the elongation of the stem and the development of new leaves and buds. Additionally, lateral meristems are responsible for secondary growth, which increases the thickness of the twig. However, primary growth primarily focuses on lengthening the twig from the apical tip.