AP BIOLOGY

Detailed explanation-1: -When the buds sprout each spring, the bud scales fall off, leaving behind a ring of scars called the bud scale scar. The distance between bud scale scars represents one year’s growth of the stem. Lenticels are small spots on the stem that allow it to exchange gases with its environment.

Detailed explanation-2: -BUD SCALE SCARS. These are scars left by the terminal bud of the previous season. They are narrow closely spaced scars that circle the twig. As each grouping of bud scale scars marks the end of one growing season, they can be used to count the age of the twig.

Detailed explanation-3: -Bud scales are often covered by leaf wax and hairs which help protect the apical meristem from dessication and other environmental stresses. When the bud is released from dormancy and the new shoot grows, the scales usually drop off leaving a series of scars that demark where the new shoot growth begins.

Detailed explanation-4: -Scars on the potato represent scale leaf. It bears eyes or buds in its axil. New potato plants grow from these eyes or buds.

Detailed explanation-5: -Bundle scars are circular or barred regions within the leaf scar where bundles of vascular tissue that had connected the leaf and the stem broke off. The number of bundle scars in a leaf scar is sometimes used as an identifying mark as they are often consistent across a species.