Lab manual definitions

Question 1

Monocot

Answer 1

Member of a clade of flowering plants that have only a single embryo seed leaf or cotyledon.

Question 2

Dicot

Answer 2

A traditional term used to refer to plants with two seed leaves or cotyledons. Recent molecular evidence indicates that dicots do not form a true clade.

Question 3

Epidermis

Answer 3

In a plant, the outermost layer of cells, typically one cell thick.

Question 4

Vascular bundle

Answer 4

Strands of primary phloem and xylem, often surrounded by a bundle sheath, and found in shoots and leaves. In roots, the vascular tissue forms a continuous cylinder.

Question 5

Endodermis

Answer 5

A specialised layer of cells with a casparian strip, surrounding the vascular tissue in roots.

Question 6

Casparian strip

Answer 6

A band of cells in the cell walls of the endodermis that is impregnated with a chemical substance that forms a diffusion barrier to water and solutes moving through the wall.

Question 7

Xylem

Answer 7

The vascular tissue that transports water and solutes from the roots to other parts of the plant.

Question 8

Phloem

Answer 8

The vascular tissue that transports photosynthetic products from leaves to areas of growth and storage, including the roots.

Question 9

Parenchyma

Answer 9

Metabolically active plant tissue consisting of thin-walled cells, often with air filled spaces at the cell corners.

Question 10

Collenchyma

Answer 10

A specialised parenchyma with irregular thickened, pectin-rich cell walls that functions in support of growing parts of a stem or leaf.

Question 11

Sclerenchyma

Answer 11

Plant tissue composed of cells that are dead at maturity, with thick lignified secondary cell walls. Functions in the support of non-growing regions of the plant.

Question 12

Fibre

Answer 12

An elongated, tapered sclerenchyma cell that provides structural support.

Question 13

Lignin

Answer 13

A highly branched phenolic polymer that is deposited in the secondary cell wall to provide strength.

Question 14

Meristem

Answer 14

A site of plant cell division.

Question 15

Cambium

Answer 15

The layer of meristematic cells between the xylem and phloem that produces lateral growth of the stem or root.

Question 16

Primary meristem

Answer 16

Meristems formed during embryogenesis, and which are found at the shoot and root apex. Responsible for increases in organ length.

Question 17

Secondary meristem

Answer 17

Meristem formed after germination, including axillary and lateral meristems. The vascular cambium which increase stem and root width is an example of a secondary meristem.

Question 18

Lateral meristem

Answer 18

Secondary meristem that increases organ width. An example is the vascular cambium.

Question 19

Vascular cambium

Answer 19

The layer of meristematic cells between the xylem and phloem that produces lateral growth of the stem or root.

Question 20

Cork cambium

Answer 20

A lateral meristem that develops in the cortex, and which produces the secondary protective layer called the periderm.

Question 21

Lateral roots

Answer 21

These roots arise from the pericycle (inside the endodermis) and grow outwards through the cortex to establish a new growth axis.

Question 22

Pericycle

Answer 22

A cell layer of the vascular cylinder of the root, inside the endodermis, where cell divisions occur that give rise to lateral roots.

Question 23

Quiescent centre

Answer 23

The central region of the root meristem where cells divide more slowly (or not all) than in surrounding regions. Believed to control root organisation and development.

Question 24

Elongation zone

Answer 24

The region of rapid cell elongation in a root found immediately basal (towards the base of the root) of the meristem. responsible for root extension.

Question 25

Differentiation zone

Answer 25

The region of the root where cells, having finished elongation, undergo further development including the formation of root hairs.

Question 26

Fascicular cambium

Answer 26

The vascular cambium that forms between the primary xylem and phloem.

Question 27

Interfascicular cambium

Answer 27

The vascular cambium that develops in the cortex between individual vascular bundles.

Question 28

Osmosis

Answer 28

The movement of water across a selectively permeable membrane to a region of lower water potential.

Question 29

Hypertonic

Answer 29

A solution with lower water potential; that is, a solution with more dissolved solutes.

Question 30

Hypotonic

Answer 30

A solution with a higher water potential or fewer solutes.

Question 31

Isotonic

Answer 31

A solution that has the same water potential.

Question 32

Plasmolysis

Answer 32

The shrinking of the protoplasm (cytoplasm and vacuole) of a cell when placed in a hypertonic solution, due to a loss of water.

Question 33

Turgor pressure

Answer 33

In a plant cell, turgor pressure develops because of water flowing into the cell because of dissolved solutes. The pressure pushes back against the cell wall, generates the firmness of the cell, and provides the force for cell expansion.

Question 34

Protoplast

Answer 34

The living contents of the cell (plasma membrane, cytoplasm, vacuole etc) after the cell wall has been removed.

Question 35

Epidermal peel

Answer 35

The outer layer of a plant (epidermis) after it has been removed from the plant. A monolayer of cells used for experiments.