13.1.4 Primary Growth: Stem Growth and Development

Question 1

Primary Growth: Stem Growth and Development

Answer 1

• Review: Primary growth in plants occurs in the apical meristem.
• When plants grow in height, they grow from their apical meristem.
• The monocot stem has no vascular cambium and has vascular bundles scattered throughout ground tissue.
• The dicot stem has vascular bundles arranged in a ring and a vascular cambium, which is a lateral meristem

Question 2

note

Answer 2

• Vascular tissue in stems is arranged into vascular bundles. In a monocot stem (left), the vascular bundles are scattered throughout the ground tissue of the stem.
• The close-up of a vascular bundle in monocots (referred to as a monocot face) reveals the arrangement of xylem and phloem. Xylem tissue is typically found oriented toward the inside of the stem (in this diagram the lower three circular shapes). An air space is present in the lower portion of the xylem and represents the first xylem tissues that formed and later disintegrated (the lower circular shape). Phloem is found oriented toward the outside of the stem (the upper circular shape)
• The vascular bundles of the stem converge to form the central stele of the root.
• The vascular bundles of a dicot stem are arranged in a ring around the central pith. Each vascular bundle consists of phloem oriented toward the outside of the stem, and xylem oriented toward the center of the stem.
• Between the xylem and phloem is vascular cambium, which is meristematic tissue that gives rise to secondary xylem and phloem.

Question 3

Shoots lengthen through activity at the ______________.

Answer 3

• apical meristem

Question 4

Vascular bundles are embedded in which tissue of the monocot stem?

Answer 4

• ground tissue

Question 5

Choose the correct sequence of layers from the inside to the outside of the stem of a dicot.

Answer 5

• pith, xylem, cambium, phloem, cortex

Question 6

The vascular bundles of dicot stems have their xylem facing the ______________ and their phloem facing the _____________.

Answer 6

• pith; cortex

Question 7

True or false?
Monocot stems have their vascular tissue arranged in a ring, while dicots have their vascular tissue scattered throughout the ground tissue.

Answer 7

• false

Question 8

Leaves develop from the

Answer 8

• apical meristem of the shoot.