Stems

Question 1

What distinguishes stems from roots?

Answer 1

Stems typically have a thick cuticle on the epidermal cells, nodes, internodes, and vascular tissues (xylem and phloem).

Question 2

What is a node?

Answer 2

A node is the area of a stem where a leaf or leaves are attached.

Question 3

What is the function of the apical meristem in stems?

Answer 3

The apical meristem contributes to the stem’s growth in length by producing primary tissues.

Question 4

What are the three primary meristems that develop from the apical meristem?

Answer 4

1) Protoderm (epidermis), 2) Ground meristem (pith and cortex), 3) Procambium (primary xylem and phloem).

Question 5

What is transpiration, and how does it relate to xylem transport?

Answer 5

Transpiration is the process of water moving up through the xylem from roots to leaves, driven by evaporation.

Question 6

How is phloem transport different from xylem transport?

Answer 6

Phloem transport moves food (sucrose) in any direction from a source to a sink, unlike xylem which only moves water upwards.

Question 7

What are the differences between herbaceous and woody dicotyledonous stems?

Answer 7

Herbaceous stems are green and primarily consist of primary tissues, while woody stems develop secondary xylem (wood) and have secondary growth.

Question 8

What are specialized stems and how are they identified?

Answer 8

Specialized stems differ from typical stems but have nodes, internodes, and axillary buds, distinguishing them from roots and leaves.

Question 9

What is a rhizome?

Answer 9

A rhizome is a horizontal stem that grows below ground, producing adventitious roots and having nodes and internodes.

Question 10

How do runners differ from rhizomes?

Answer 10

Runners grow above ground and have long internodes, while rhizomes grow below ground.

Question 11

What is a stolon?

Answer 11

Stolons are similar to runners but grow beneath the ground and can form tubers, like in the case of Irish potatoes.

Question 12

What are tubers, and what role do they play in plants?

Answer 12

Tubers are thickened stems that store starch, allowing the plant to overwinter, like in potatoes.

Question 13

What is a bulb, and what are its components?

Answer 13

A bulb is a large bud surrounded by fleshy leaves that store food, with a small stem at the lower end and adventitious roots growing from the bottom.

Question 14

What are cladophylls, and in which plants are they found?

Answer 14

Cladophylls are flattened stems that resemble leaves, found in plants like butcher’s broom, asparagus, and prickly pear cacti.

Question 15

What is the function of xylem in vascular plants?

Answer 15

Xylem transports water and nutrients from the roots to the rest of the plant, moving water vertically through vessels and laterally through pits.

Question 16

What is the function of phloem in vascular plants?

Answer 16

Phloem transports food, mainly sucrose, in various directions depending on the plant’s needs, from sources (where food is produced or stored) to sinks (where food is used or stored).

Question 17

What are annual rings in woody stems?

Answer 17

Annual rings consist of spring wood (larger vessel elements) and summer wood (smaller vessels), representing one year of growth in the xylem.

Question 18

What is the vascular cambium, and what tissues does it produce?

Answer 18

The vascular cambium is a meristematic layer that produces secondary xylem (wood) and secondary phloem, increasing the girth of the stem.

Question 19

What are monocotyledonous stems, and how are they structured?

Answer 19

Monocot stems have vascular bundles scattered throughout the stem, with xylem closer to the center and phloem nearer to the surface.

Question 20

What are the main tissue patterns found in stems?

Answer 20

The primary tissue patterns are prostele (solid core), siphonostele (tubular with pith), and eustele (discrete vascular bundles).

Question 21

What are the main features of a corm, and how does it differ from a bulb?

Answer 21

A corm is mainly stem tissue covered with papery leaves and stores food, whereas a bulb has fleshy leaves that store food and a small stem at the base.

Question 22

What is the function of tendrils in specialized stems?

Answer 22

Tendrils, such as those in Boston ivy, help the plant climb by attaching to surfaces with adhesive disks or adventitious roots.

Question 23

How do thorns function in plants, and what kind of stem modification are they?

Answer 23

Thorns are modified stems that protect plants from herbivores by providing a physical defense.

Question 24

What are cladophylls, and how do they differ from true leaves?

Answer 24

Cladophylls are flattened stems that perform photosynthesis and resemble leaves, but they bear small scale-like leaves at their nodes.

Question 25

What role do stolons play in plant reproduction?

Answer 25

Stolons, which grow underground, produce new plants at their tips or along their length, as seen in Irish potato plants.

Question 26

How are specialized stems adapted for food storage?

Answer 26

Specialized stems like tubers, bulbs, and corms are adapted to store starch and other nutrients, allowing plants to survive unfavorable seasons.