Chapter 31

Question 1

A discrete population of actively dividing, totipotent cells; apical meristems are located at the tip of stems and roots and produce cells that allow plants to grow in length, while lateral meristems surround stems and roots and produce cells that allow growth in diameter.

Answer 1

meristem

Question 2

In phylogenetic trees, the point where a branch splits, representing the common ancestor from which the descendant species diverged. In plants, the point on a shoot where one or more leaves are attached.

Answer 2

node

Question 3

The segment between two nodes on a shoot.

Answer 3

internode

Question 4

A group of totipotent cells near the tip of a stem or branch that gives rise to new shoot tissues in plants.

Answer 4

shoot apical meristem

Question 5

A gene that contributes to meristem stability and function.

Answer 5

meristem identity gene

Question 6

A meristem that forms at the base of each leaf.

Answer 6

axillary bud

Question 7

An organ in its earliest stage of development; leaf primordia form near the tips of shoot apical meristems and develop into leaves.

Answer 7

primordia

Question 8

One of many like structures formed from leaf primordia that, together, protect shoot apical meristems from desiccation and damage due to cold.

Answer 8

bud scale

Question 9

A cell that retains the capacity for cell division and gives rise to both xylem and phloem

Answer 9

procambial cell

Question 10

In a stem, the region between the epidermis and the vascular bundles, composed of parenchyma cells. In the mammalian brain, the highly folded outer layer of gray matter, about 4 mm thick, made up of densely packed neuron cell bodies and their dendrites. In the mammalian renal system, the outer layer of the kidney.

Answer 10

cortex

Question 11

In a stem, the region inside the ring of vascular bundles.

Answer 11

pith

Question 12

A plant hormone that stimulates the elongation of stems.

Answer 12

gibberellic acid

Question 13

The increase in plant length made possible by apical meristems.

Answer 13

primary growth

Question 14

The increase in plant diameter resulting from meristems that surround stems and roots.

Answer 14

secondary growth

Question 15

The source of new cells that allows plants to grow in diameter.

Answer 15

lateral meristem

Question 16

Lateral meristem that is the source of new xylem and phloem.

Answer 16

vascular cambium

Question 17

Lateral meristem that renews and maintains an outer layer that protects the stem against herbivores, mechanical damage, desiccation, and fire.

Answer 17

cork cambium

Question 18

New xylem cells produced by vascular cambium, which are located to the inside of the vascular cambium.

Answer 18

secondary xylem

Question 19

New phloem cells produced by the vascular cambium, which are located to the outside of the vascular cambium.

Answer 19

secondary phloem

Question 20

In long-lived trees, the layer adjacent to the vascular cambium that contains the functional xylem.

Answer 20

sapwood

Question 21

The center of the stem in long-lived trees, which does not conduct water.

Answer 21

heartwood

Question 22

One of the many rings apparent in the cross section of the trunk of a tree, produced by decreases in the size of secondary xylem cells at the end of the growing season, that make it possible to determine the tree’s age.

Answer 22

growth ring

Question 23

In angiosperms, a narrow cell with thick walls that provides mechanical support in wood. In animals, a term for a muscle cell, which produces forces within an animal’s body and exerts forces on the environment.

Answer 23

fiber

Question 24

An individual cell that is part of a xylem vessel for water transport in plants.

Answer 24

vessel element

Question 25

In roots, a single layer of cells just to the inside of the endodermis from which new root apical meristems are formed, allowing roots to branch.

Answer 25

pericycle

Question 26

A plant hormone that triggers stomatal closure, stimulates root elongation, and maintains seed dormancy.

Answer 26

abscisic acid

Question 27

The effect of the photoperiod, or day length, on flowering.

Answer 27

photoperiodism

Question 28

A plant that flowers only when the day length is less than a critical value.

Answer 28

short-day plant

Question 29

A plant that flowers only when the light period exceeds a critical value.

Answer 29

long-day plant

Question 30

A plant that flowers independently of any change in day length.

Answer 30

day-neutral plant

Question 31

A prolonged period of exposure to cold temperatures necessary to induce flowering.

Answer 31

vernalization

Question 32

(of an immature or stem cell) capable of giving rise to any cell type or (of a blastomere) a complete embryo.

Answer 32

totipotent

Question 33

Any member of a class of signaling molecules produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour.

Answer 33

hormone

Question 34

Is the phenomenon whereby the main, central stem of the plant is dominant over (i.e., grows more strongly than) other side stems; on a branch the main stem of the branch is further dominant over its own side branchlets.

Answer 34

apical dominance

Question 35

The turning of all or part of an organism in a particular direction in response to an external stimulus.

Answer 35

tropism

Question 36

What are the five major plant hormones, where are they produced, and how are they transported?

Answer 36

Auxin, gibberellin, cytokinin, ethylene, and abscisic acid.

Question 37

How do auxin and cytokinin interact to explain plant growth patterns?

Answer 37

They help with plant growth dealing with height and width making sure it is balanced

Question 38

What, developmentally, is a flower (i.e., what organ(s) is/are modified into flowers)? What are the parts of the flower? See figure.

Answer 38

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