Answer:
Primary growth: elongation, apical meristem, lateral meristem, increases exposure to light.
Secondary growth: vascular cambium, cork cambium, increases exposure to light.
Both: growth in thickness, provides structural support.
Neither: occurs in plants that live only one year, occurs in plants that live many years.
Explanation:
Every plant presents primary growth, while only woody dicots and gymnosperms present secondary growth. It does not depend on being annual or perennial. In primary growth cells get elongated and the plant grows in length due to the activity of the apical meristems and, grows in thickness, due to the activity of the lateral meristem. In secondary growth, there is no apical growth and the vascular cambium and the cork cambium are the ones in charge of thickness growth. The vascular cambium is located between primary xylem and phloem and is responsible for secondary xylem and phloem production. Vascular tissues are involved in the flow of nutrients and water, which is improved by the secondary growth, increasing the vascular flow. Vascular tissue is also involved in shoot resistance. This last characteristic might be considered as structural support. The cork cambium produces cork to the exterior and felodermis to the interior. Exposure to light is related to primary growth, this is why plants that compete for light or that lives in hidden places keep growing in high.
