Lab 1

Question 1

differentiation

Answer 1

process in which cells become specialized in structure and function

Question 2

tissue

Answer 2

an aggregate of cells usually of a particular kind together with their intercellular substance that form one of the structural materials of an organism

Question 3

meristem

Answer 3

a region of plant tissue consisting of actively dividing cells forming new tissue

Question 4

primary meristem

Answer 4

meristem that produces the tissues of the primary plant structure
RAM and SAM

Question 5

indeterminate growth meristem

Answer 5

produces parts of the plant that can grow for variable periods of time, and vary in size and shape dependent on the local environment

Question 6

determinate growth meristem

Answer 6

usually produces part of the plant that has a predictable size and form, such as the flower

Question 7

stem cell/initial cell

Answer 7

undifferentiated cell present in the meristematic tissues

cell from which all other cells with specialized functions are generated

Question 8

histogen

Answer 8

zone of primary tissue from which the specific parts of a plant organ are believed to be produced

plerome, periblem, dermatogen and calyptrogen (not always)

Question 9

procambium

Answer 9

primary tissue of roots and shoots that forms the vascular tissue

Question 10

primary structure

Answer 10

first structure of the plant consisting of primary tissues

Question 11

root

Answer 11

an organ in vascular plants that anchors the plant and enables it to absorb water and minerals from the soil

first organ to develop in germinating seed

Question 12

root cap

Answer 12

a structure that covers the tip of a root, protecting the root from injury

it covers meristematic cells within the root tip

Question 13

columella

Answer 13

central part of root cap, it is made up of cells arranged in files

the cells contain multiple amyloplasts (statoliths) with starch

the cells contribute to gravitropism by the movement of statolith to in cells

Question 14

root border cells

Answer 14

cells that separate from the root tip of higher plants and disperse individually in the soil solution (or water)

their functions are: protection from phatogens, modification of chemical and physical soil properties, regulation of symbioses

Question 15

statoliths

Answer 15

specialized plastids (amyloplasts) containing dense starch grains, that let plants know up from down = they take part in gravitropism

Question 16

radicle

Answer 16

an embryonic root of a plant

it is the first organ to develop during germination

it grows downward into the soil, anchoring the seedling

Question 17

adventitious root

Answer 17

roots that rise form the point other than radicle or root axis of the plant e.g. from stems or leaves; examples are aerial roots and prop roots above ground

Question 18

seminal root

Answer 18

one of the first structures to emerge from a germinating seed

seminal roots make up the root with fibrous root system, where radicle is retarded

Question 19

lateral root

Answer 19

a secondary plant root that extends horizontally from another root in secondary meristems, when the cell cycle and mitosis start in cells of pericycle

Question 20

fibrous root system

Answer 20

monocots and ferns

fibrous root system forms a dense network of roots that is closer to the soil surface

the roots making it up are called seminal roots and they branch out

the radicle is retarded or it does not grow

Question 21

tap root system

Answer 21

dicots

they are made up of a central large root, which develops from the radicle and it is called a taproot

from the taproot, lateral roots develop

Question 22

root hair zone

Answer 22

primary root structure

small and thin extensions of the root

it is important for water and nutrients uptake bc it has the largest surface thanks to the root hairs

Question 23

rhizodermis/epiblem

Answer 23

primary surface layer of the root, similar to epidermis but of different origin and function

the cells adhere strongly to each other, they have thin, primary cell walls, large central vacuole

includes root hairs

very little cuticle

Question 24

root hair

Answer 24

outgrowths of a root’s epidermal cells that allow for greater surface area for absorption of nutrients and water

also pathogen protection

adherence to the soil

participation in rhizosphere formation

Question 25

trichoblast

Answer 25

specialized cells from which the root hairs of epidermal cells have originated

Question 26

primary cortex

Answer 26

made up of endodermis, primary cortex parenchyma and epidermis

transport and store nutrients and provide support

Question 27

stele

Answer 27

pericycle and strands of vascular tissue - composed of vascular bundles , which are formed from primary xylem and primary phloem

pericycle is inactive procambium

Question 28

rhizosphere

Answer 28

the narrow region of soil or substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome

Question 29

exodermis

Answer 29

cell layers just under the epidermis to prevent water loss

exodermis represents an unicellular cell layer located at the outer surface of the root directly below the root epidermis

Question 30

parenchyma

Answer 30

fundamental tissue composed of thin-walled living cells, there are different types ground parenchyma, hydrenchyma, chlorenchyma, storage parenchyma, aerenchyma

Question 31

endodermis

Answer 31

the innermost layer of the cortex in plant roots; a cylinder one cell thick that forms the boundary between the cortex and the vascular cylinder

casparian strips
suberin lamellae
could be secondary wall thickenings

it consist also of passage cells that stay in the second stage of development and provide pathways for transport of water and nutrients and entrance of mycorrhizal fungi

Question 32

symplast

Answer 32

the continuum of cytoplasm connected by plasmodesmata between cells

transport across plasmalemma and cytoplasm through plasmodesmata

Question 33

apoplast

Answer 33

the continuum of cell walls plus the extracellular spaces

transport through unmodified, cellulose cell walls and intercellular spaces

Question 34

Casparian strip

Answer 34

hydrophobic cell wall impregnations; they form a barrier forcing ions to pass through the selectively permeable plasma membrane into the cytoplasm rather than move along the cell wall

control of water and solute transport

forces symplast

Question 35

pericycle

Answer 35

the outermost layer of the vascular cylinder of a root, where lateral roots originate

mitoticaly inactive procambium

site for the initiation of lateral roots as the secondary meristem

Question 36

vascular bundle

Answer 36

plant stem structure that contains xylem and phloem tissue

it can be found in the stele

Question 37

phloem

Answer 37

the vascular tissue in plants that conducts sugars and other metabolic products downward from the leaves

most of the phloem is alive

Question 38

primary phloem

Answer 38

vascular tissues originating from apical meristem growth it is present in primary structures it is important for transport of nutrients

Question 39

protophloem

Answer 39

the part of the primary phloem that differentiates early, while adjacent cells are still elongating

Question 40

metaphloem

Answer 40

the part of the primary phloem that differentiates late, after adjacent cells have completed their elongation

Question 41

xylem

Answer 41

vascular tissue that carries water upward from the roots to every part of a plant

most cells are dead

Question 42

primary xylem

Answer 42

formed at root and shoot apex early in development, they form vascular bundles in leaves and young stems

Question 43

protoxylem

Answer 43

the part of the primary xylem that differentiates early, while adjacent cells are still elongating

Question 44

metaxylem

Answer 44

the part of the primary xylem that differentiates late, after adjacent cells have completed their elongation