Biolab 4: Young Stems and Roots

Question 1

collenchyma cells

Answer 1

thick-walled, elongate, and particulary suited to support the stem when it is young and growing, they give strong, stable support , yet are stretchable, adjusting to stem elongation

Question 2

fibrovascular bundles

Answer 2

individual tracts of tissues running lengthwise in the stem and appearing in cross section as cell clusters called bundles

Question 3

sclerenchyma

Answer 3

are also known as the bundle cap fibres, can also surround the bundle

• tough sclerenchyma cap reinforces each tract (bundle) as it extends the length of the stem
• very long with thick , rigid but elastic walls
• take push, pull but can always reboun dto their original
• gives stem strength but also allows flexibility to the stress of wind and weight of leaves
• used to make rope ,twine and fabrics

Question 4

parenchyma cells

Answer 4

thin walled cells that fill the centre of the dicot stem also around each vascular bundle

• contain water which build up turgor pressure
• they store materials
• all together they serve as a lightweight filler material that keeps the fiibrovascular bundles in place
• tissue containing parenchyma cells have different locations base don where they are located
• in center of stem called pith
• between vascular bundles called pith rays
• between epidermis and the other edge of the vascular bundles is called cortex

Question 5

turgor pressure

Answer 5

pressure developed by the water present in plant cells it keeps plant parts (leaves, flowers, and stems rigid or turgid)

Question 6

vascular bundle of dicot

Answer 6

• arranged in a ring,
• green cells are phloem, large ones are sieve tube members and smaller ones are companion cells or phloem parenchyma cells

Question 7

sieve tube member

Answer 7

long cells stacked one above teh other forming a pipe like sieve tube, have perforated end walls,c alled sieve plates

Question 8

companion cells

Answer 8

speicalized cells whose nuclei are though tto have some control over the functioning of the cytoplasm in the sieve tube member that has no nucleus

Question 9

phloem parenchyma

Answer 9

cells serve as a filler tissue and for storage

Question 10

xylem in dicot

Answer 10

makes up the innermost tissue of vascular bundle

• tracheids and vessel elements
• vessel elements are larger in diamter then tracheids
• vessel elements are barrel shaped cells stacked on each other forming a pipe-like
• water moves through the vessels and also through the more slelnder tracheids but at a slower rate

Question 11

vascular cambium

Answer 11

thin layer of four sided flattened cells located between the phloem and the xylem

Question 12

chlorenchyma

Answer 12

chloroplast containing tissue

Question 13

stomata

Answer 13

opening in epidermis flanked by two guard cells, co2 and o2 pass through the stomata
- flanked by two guard cells which regualte the opening and closing

Question 14

monocot stems

Answer 14

• vascular bundles not arranged in ring
• vascualar bundles in no regular pattern, just scattered
• xylem consists of both tracheids and vessels
• phloem tissue located on outer side of xylem
• ## two types of phloem the sieve tube members and the smaller companion cells

Question 15

Root of dicot

Answer 15

..

Question 16

epdiermis

Answer 16

outermost layer of cells, some grow far out into the soil

Question 17

cuticle

Answer 17

root region,highly permeable to the soil solution

Question 18

cortex

Answer 18

very large one of rounded parenchyma cells situated between the epidermis and the vascular bundle
- large spaces allows high volume of soil solution to quickly move into the root, large surface area for absorption, supplies the energy needed to move mineral ions into the cytoplasm of the cells

Question 19

starch granules

Answer 19

storage products translocated into teh root from the shoot system

Question 20

endodermis

Answer 20

innermost layer of the cortex

Question 21

suberin

Answer 21

impermeable material, concentrated in bands known as casparian strips or bands
- thought to form barrier to the passage of anything moving through the cell walss

Question 22

vascular cylinder in root

Answer 22

is the central core of the root

Question 23

vascular bundle in root made up of 3 tisues

Answer 23

pericyle, primary xylem and primary phloem, and in mature buttercup also has cambium

Question 24

pericylce

Answer 24

narrow zone, just within the endodermis, composed of meristematic parenchyma cells

Question 25

primary xylem

Answer 25

fluted cylinder extending the length of the root - in cross section looks like star shaped
- composed of tracheids and vessel members

Question 26

primary phloem

Answer 26

• nested between ridges of xylem
• two types, sieve tube members and companion cells
• companionc ellsa re smaller, sieve tube members are large in diamter, lack nuclei

Question 27

cambial cells

Answer 27

between cluster of phloem cells and the concave part of the xylem

Question 28

vascular cambium

Answer 28

band, flat rectangular cells

Question 29

root monocot

Answer 29

..

Question 30

xylem

Answer 30

in the form of a ring

Question 31

phloem

Answer 31

• small circular zones between the xylem

Question 32

pith

Answer 32

occupies the center of the vascular cylinder

Question 33

endodermis

Answer 33

more suberin and more cellulose then in dicot roots

Question 34

cortex

Answer 34

in the corn root is smaller than the vascular bundle, bu tin monocot such as lilium may be larger

Question 35

comparison FLOWERS monocot and dicot

Answer 35

monocot- multiples of 3

dicot- multiples of 4 or 5

Question 36

comparison LEAVES monocot and dicot

Answer 36

monocot- leaf veins parallel

dicot- leaf veins reticulated

Question 37

comparison STEMS monocot and dicot

Answer 37

monocot- vascular tissue scattered w no arrangement

dicot- arranged in a ring , divided into stele and cortex

Question 38

comparison ROOTS monocot and dicot

Answer 38

monocot- fibrous root;, xylem and phloem in a ring, has pith center
dicot- tap root, phloem between arms of xylem , with no pith

Question 39

comparison SEEDS monocot and dicot

Answer 39

monocot- one cotyledon

dicot- two cotyledons