Lab 2

Question 1

protomeristem

Answer 1

a group of young meristematic cells in its early embryonic stage present at the shoot and root tip of a plant from which the other meristems are derived

Question 2

primordium

Answer 2

is an organ or tissue in its earliest recognizable stage of development, cells of the primordium are called primordial cells, from them the organ/tissue develops

Question 3

bud

Answer 3

plant structure present on the stem containing undeveloped tissue that can produce new stems and leaves,
there are lateral - responsible for development of lateral organs and apical buds - responsible for elongation

Question 4

lateral bud/axillary bud

Answer 4

buds along the sides of a stem that give rise to new shoots, either vegetative - branches and stems or generative - flowers

Question 5

apical bud

Answer 5

bud located at the tip of the stem or the branch, which is responsible for elongation

Question 6

organogenetic zone

Answer 6

pools of dividing cells that reside in the meristems, they are responsible for creation and growth of the organs

Question 7

stem

Answer 7

vascular plant organ consisting of an alternating system of nodes and internodes that support the leaves and reproductive structures,
it creates a connection between all plant organs and takes part in transport of water, minerals, metabolic products etc

Question 8

shoot

Answer 8

plant shoot consists of any plant stem together with its appendages like leaves, lateral buds, flowering stems, and flower buds

Question 9

epidermis

Answer 9

outermost layer of the stem
covered by cuticle - pathogen protection and limiting water loss
secondary, unevenly thickened, cutinized cell wall
colourless plastids (leucoplasts often)
large vacuole, anthocyanins

Question 10

primary cortex

Answer 10

made of collenchyma, parenchyma

starch sheath in dicots
serves the function of a gravitropic sensor
starch sheath cells differentiate further and they can form Casparian strip and other ultrastructural traits typical of root endodermis

Question 11

chlorenchyma

Answer 11

type of parenchymatous tissue that contains chlorophyll, assists plants in performing their photosynthetic function, can be found below the epidermis

Question 12

angular collenchyma

Answer 12

collenchyma in which cells have thicker cell walls at the ends, giving them an angular appearance, can be found in primary cortex

Question 13

lamellar collenchyma

Answer 13

collenchyma in which cells have continuous layers of thickening in their cell walls, the thickenings are in the outer and inner tangential walls, can be found in primary cortex

Question 14

ground parenchyma

Answer 14

a versatile ground tissue that generally constitutes the “filler” tissue in soft parts of plants, forms the cortex and pith of stems, the cortex of roots, the mesophyll of leaves, the pulp of fruits, and the endosperm of seeds

Question 15

druse

Answer 15

a rounded cluster of calcium oxalate crystals found in some plant cells, defense against herbivory

Question 16

idioblast

Answer 16

isolated plant cell of a different type surrounded by cells homogeneous to themselves, for example tannin cells, mucilaginous cells, secretory cells in ground parenchyma of stele

Question 17

starch sheath

Answer 17

in dicot stems
close to SAM, where primary structure is initiated
in older parts of stem, the starch sheath no longer serves as gravitropic sensor
starch sheath cells differentiate further and they can form Casparian strip and other ultrastructural traits typical of root endodermis

Question 18

stele

Answer 18

consists of pericycle, vascular tissue , ground parenchyma containing:
idioblast with druse (tannin cells, mucilaginous cells, secretory cells)

Question 19

fiber/stereid

Answer 19

a ground tissue cell with thickened cell walls, functions in support rather than conduction, may or may not retain a living protoplast at maturity

Question 20

pericycle

Answer 20

the outermost, unicellular layer of the vascular cylinder of a stem, transports water and nutrients between vascular bundles and primary cortex

Question 21

procambium

Answer 21

primary tissue of roots and shoots that forms the vascular tissue

Question 22

cambium

Answer 22

a cellular plant tissue from which phloem, xylem, or cork grows by division, resulting in secondary thickening

Question 23

collateral open vascular bundle

Answer 23

collateral = pr phloem and pr xylem opposite, radical arrangement
open = fascicular cambium present

Question 24

collateral closed vascular bundle

Answer 24

collateral = pr phloem and pr xylem opposite, radical arrangement
open = xylem and phloem are arranged side by side in the same radius which are not separated by the cambium

Question 25

sieve tube

Answer 25

cell belonging to phloem,
made of:
- simplified protoplast (nucleus, ribosomes, tonoplast, Golgi apparatus absent)
- ER, plastids and mitochondria simplified
- P protein
- non lignified cell wall
the transverse walls are transformed into sieve plates

Question 26

sieve tube member

Answer 26

a sieve element of a type present in angiosperms, a series of which are joined end to end to form sieve tubes, with sieve plates between the elements

Question 27

sieve plate

Answer 27

result of transverse walls transformation in sieve cells

Question 28

callose

Answer 28

a polysaccharide in the form of β-1,3-glucan with some β-1,6-branches and it exists in the cell walls and plays important roles during a variety of processes in plant development and/or in response to multiple biotic and abiotic stresses

Question 29

companion cell

Answer 29

supports support long distance transport
in angiosperm, in gymnosperm as albuminous cells
low vacuolation of protoplast
numerous: active mitochondria, RER and ribosomes
large plastids
transfer cell role

Question 30

phloem parenchyma

Answer 30

storage
auxiliary functions in short distance transport
in angio and gymnosperms
transfer cell role: parenchymatous cell specialised in active transport of substances across plasma membrane

Question 31

phloem fibers

Answer 31

mechanical strength and support
in angio and gymnosperms

Question 32

tracheid

Answer 32

part of xylem, a long and tapered lignified cell in the xylem of vascular plants
lignified secondary cell wall
support + water transport
bordered pits providing water movement between adjacent cells

Question 33

vessel

Answer 33

part of xylem,
shorter, thicker
perforation plates
more efficient than tracheids
ferns, gymnosperm and angiosperm plants

Question 34

vessel member

Answer 34

the principal water-conducting cells in angiosperms and are characterized by areas that lack both primary and secondary cell walls, known as perforations

Question 35

perforation plate

Answer 35

an area or areas in which there is no shared wall material or membrane in vessels

Question 36

xylem parenchyma

Answer 36

has a cell walls thickened with pits of various types
storage and mediating exchange between tracheal elements and other cells
they divide into axis and ray (along radial axis of stem) orientation

Question 37

xylem fiber

Answer 37

made up of dead sclerenchyma cells in between the xylem vessels and tracheids of the xylem tissue, and chiefly provide mechanical support

Question 38

ray

Answer 38

the radial component of the secondary plant body,
formed near the pith from the interfascicular parenchyma, connecting the pith with the cortex, are termed medullary rays; all other rays originate from the cambium

Question 39

pith

Answer 39

a tissue in the stems of vascular plants
composed of soft, spongy parenchyma cells, which in some cases can store starch

Question 40

air canal

Answer 40

aerenchyma formed gaps in stem allowing gases to flow between the shoot and the ground

Question 41

vine/liana

Answer 41

plants with long, flexible, climbing stems that are rooted in the ground, and usually have long dangling branches