Annual rings in woody stems are caused by an increase in rings of the

a. primary xylem.

b. primary phloem.

c. secondary phloem.

d. secondary xylem

Annual rings in woody stems are caused by an increase in rings of the: D. secondary xylem The basic function of a seconday xylem is to transport water to shoots and leaves. Water transporation contributed to the amount of woods produced druing the growing season that also contribute to the formation of annual rings in woody stems

The answer is letter D. Annual rings in woody stems are caused by an increase in rings of the secondary xylem. During the fall, the secondary xylem develops dense woods. Thin woods are develop during the spring which marks the formation of ring on its annual growth.