GENBIO: Stems

Question 1

Two important functions of stems

Answer 1

1. They hold leaves up to the sunlight

2. They transport substances between roots and leaves

Question 2

Leaves attach to the stem at these structures.

Answer 2

Nodes

Question 3

The regions of stem between the nodes.

Answer 3

Internodes

Question 4

These are small and found where leaves attach to nodes.

Answer 4

Bud

Question 5

These contain undeveloped tissue that can produce new stems and leaves.

In larger plants, stems develop woody tissue that helps support leaves and flowers.

Answer 5

Buds

Question 6

The arrangement of tissues in a stem differs among seed plants.

Vascular bundles are scattered throughout the stem / throughout the ground tissue.

Answer 6

Monocots

Question 7

The arrangement of tissues in a stem differs among seed plants.

Vascular bundles are arranged in a ringlike pattern.

Answer 7

Dicots and most gymnosperms

Question 8

These stems have a distinct epidermis, which encloses vascular bundles.

Answer 8

Monocot stems

Question 9

Components of each vascular bundle:

Answer 9

1. Xylem tissue

2. Phloem tissue

Question 10

Consists mainly of parenchyma cells

Answer 10

Ground tissue

Question 11

Dicot stems have vascular bundles arranged in a ringlike pattern.

The parenchyma cells inside the vascular tissue are known as ___.

Answer 11

Pith

Question 12

The method of growth in which stems increase in length.

For the entire life of the plant, new cells are produced at the tips of roots and shoots.

Answer 12

Primary growth

Question 13

It is produced by cell divisions in the apical meristem. It takes place in all seed plants.

Answer 13

Primary growth of stems

Question 14

Primary growth of stems is produced by cell divisions in the ____.

Answer 14

apical meristem

Question 15

The method of growth in which stems increase in width.

In conifers and dicots, it takes place in the vascular cambium and cork cambium.

Answer 15

Secondary growth

Question 16

The cambium which produces vascular tissues and increases the thickness of stems over time.

The addition of new tissue in these cambium layers increases the thickness of the stem.

Answer 16

Vascular cambium

Question 17

The cambium produces the outer covering of stems.

The addition of new tissue in these cambium layers increases the thickness of the stem.

Answer 17

Cork cambium

Question 18

Formation of the Vascular Cambium

Once secondary growth begins, the vascular cambium appears as a ____.

Answer 18

thin layer between the xylem and phloem of each vascular bundle.

Question 19

Formation of the Vascular Cambium

The vascular cambium divides to produce ___.

Answer 19

xylem cells toward the center of the stem; phloem cells toward the outside.

Secondary phloem
Secondary xylem

Question 20

Formation of Wood
___ is actually layers of xylem. These cells build up year after year.

“wood”
“bark”

Answer 20

Wood

Question 21

Formation of Wood
As woody stems grow thicker, older xylem cells near the center of the stem no longer conduct water.
This is called _____. It support the tree.

Xylem: __

Answer 21

heartwood

Question 22

Formation of Wood
It surrounds the heartwood.
It is active in water and mineral transport.

Xylem: __

Answer 22

Sapwood

Question 23

Formation of Bark

On most trees, ___ includes all of the tissues outside the vascular cambium.

Answer 23

bark

Question 24

The tissues outside the vascular cambium.

Answer 24

1. Phloem
2. The cork cambium
3. cork

Question 25

It produces new xylem and phloem, which increase the width of the stem.

Next to sapwood.

Answer 25

Vascular cambium

Question 26

It transports sugars produced by photosynthesis.

Next to vascular cambium.

Answer 26

Phloem

Question 27

It produces a protective layer of cork.

Next to phloem.

Answer 27

Cork cambium

Question 28

It contains old, nonfunctioning phloem that protects the tree.

Next to Cork cambium.

Answer 28

Cork