1. plant cell

First Chapter Plant Cellsone Form and Structure of Plant Cells

★Definition

The structural and functional unit of a tissue ,

and consequently of the plant body itself , is known

as a cell . Some species or kind of plants consist of

single cell , but large type are make up of

uncountable millions , or even billions , of these

structural units.

Chlamydomonas Nostoc commune Vauch

1.Shape and Size of Plant Cells

It has various shapes and sizes.

Cell , which distribute in differ part of frond and

perform differ function , has differ form and size .

plant cell , commonly 10 ～ 100μm(diameter)

least cell , as if

bacterial diameter only

0.2μm

Big cell , like cell of

storage parenchyma

1mm

Fiber cell of flax 4cm

long

Fiber of ramee 55cm

long

2.Basic Structure and Function

of Plant cells

DefinitionMicroscopic structure: there can be seen the cell

structure with microscope, called microscopic structure.

Submicroscopic structure: there can be seen the cell structure with electron microscope , termed submicroscopic structure.

1.Cell wall 2.nuclear membrane 3.nucleochylema 4.nucleolus 5.plasmalemma 6.Cytoplasm 7.vacuole membrane 8.chloroplast 9.vacuole

1. nuclear membrane

2. nucleolus

3.chromosome

4. Cell wall

5. plasmalemma

6. vacuole membrane

7. vacuole

8. Chloroplast

9.Mitochondria

10.microtuble

11. Endoplasmic reticulum

12.Ribosome

13.14.microbody15.golgi body

Microscopic structure

submicroscopic structure

constitute★

一、 cell wall

二、 protoplast

三、 ergastic substance

Intercellular Layer ： It is thin layers owned in common between cell wall and cell wall . Primary Wall: By cellulose , hemicellulose and pectin material that protoplasm secrete, increase in interior side of intercellular layer. Secondary Wall: After the cell wall stops growing, are accumulating some materials coming into being in the interior of the primary wall on each gradually, make the cell wall increase and take shape on concentric storey thick.

simple pit

Ⅰ. pit 　 bordered pit half bordered pit

Ⅱ.plasmodesmata

Pit

The secondary wall does not increase thick

evenly , leave some and has not increased

the thick part in a lot of places during the

process of thickenning, called the pit.

Ⅰ.Simple pit .bordered pit .half boredered pitⅡ Ⅲ

1.tangent plane view 2.exterior view

Bordered pit of pine’s stem and Radix et Rhizoma Rhei

Ⅱ.plasmodesmata There are a lot of very

thin protoplasm silks that cross and come into being the very small hole on the primary wall and get in touch each other among the cells, this kind of protoplasm silk is called plasmodesmata.

Plasmodesmata of Persimmon core

lignification suberizationⅢ. Specification of Cell Walls cutinization mucilagization mineralization

1.lignification: The cell wall has increased more lignin while adding and growing.

Distinguish: it was stained Red when ①adding meta benzene and three phenol + dense hydrochloric acid is.

②Example: vessel , wood fiber , stone cell.

2. suberization: Have increased the fat phellem in

the cell wall.

①Distinguish :it was dyed Red when adding

Sudan test solution(TS) is.Ⅲ

②Example: Brown outer bark trunk outside.

3. cutinization ： Fat cutin except not being

pack the cell wall , form a layer of cuticles

outside epidermis of stem often.

①Distinguish :it was dyed when adding

Sudan test solution is orange.Ⅲ

②Example: The seed of the castor-oil plant ,

stem peel of the sugarcane.

4.mucilagization: Cellulose and such

composition as the pectin ,etc. in the cell

wall change but forms the mucus .

①Distinguish :it was stained Red when

adding Red reagent of ruthenium .

②Example: In the epidermis cells of plantain

, linseed.

5. mineralization: Contain the silicon or the

calcium ,etc. in the cell wall.

①Distinguish :The silicon can be dissolved

in the hydrogen fluoride(HF), but does not

dissolve in the acetic acid or denser

sulphuric acid .

②Example:Gramineous Stem and leaf

cytoplasm nuclear membrance ②protoplast nucleus nuclear sap nucleolus chromatin

chloroplast plastids leucoplast Organelle chromoplast vacuoles

There are all life matter in the cell, called protoplast .

Chloroplast:green little grains(leaf) leucoplast:achromatous and global

grains (immature organ ) Chromoplast:anomalous red,yellow,and

orange grains(flower,fruit,seed) Three kinds of plastid can convert

mutually. Vacuoles:there are many little vacuoles

in the delicate cell , but in mature ones there is only one big vacuole can be seen which occupied most part of the cell.

Mutually converting of plastic

③Ergastic Substance The vegetable cell in the life process, produces

various non- life matter as a result of the metabolism activity, called Ergastic Substance.

Ⅰ.starch grain: hilum , annular striation lamellae

reserve starch:

①simple starch grain

②compound starch grain

③half compound starch grain

1.2.3.4.simple starch grain

(1.lambdoidal hilum 2.short gap)

5.compound starch grain

Ⅱ.Inulins Fan-shaped and yellow

Ⅲ.Proteins(aleurone grain) Those are composed together by protein crystal ,

spherical albuminous body and amorphous stuffed gelatin. Add one drop iodine-potassium iodide TS , the protein turns yellow.

Ⅳ.Fats and Fatty Oils Add several drops of Sudan TS(Ⅲ 试液 ) oil

droplet contained in the cell stained red.

Ⅴ.Crystals ① calcium oxalate crystal solitary crystal : square-shaped, diamond,

rectangle or double-conical octahedrons

acicular crystal : scattered or needle-like cluster

cluster crystal: asteroid or clusters

crystal sand: irregular, polyhedrons

columnar crystal : long is cylindrical, the length approximately is above diameter 4 times

② calcium carbonate crystal

(cystolith): like a string of grape [locate in

Moraceae or Acanthaceae ]

Calcium carbonate crystal

Ⅰcysyolith （ tangent plane view ） in fig leaf

Ⅱ exterior view

Besides , physiological active substance

like enzyme , vitamin , auxin , antibiotic ,

tannins ， etc.

Two Division of Plant cells

Cell division is necessary and play important role for embryo to little frond to mature frond( possessing root , stem and leaf , flower , fruit , seed).

Three types:( 一 )mitosis ( 二 )amitosis ( 三 )meiosis

㈠ mitosis①interphase : the cytoplasm is denser ,

the nucleus is big , nuclear menbrane with the nuclear sap can be seen clearly.

②prophase There inside the nucleus emerge condensed

granulose chromatin and then gradually become the clubbed chromosome.

③metaphase: the nuclear membrane , the nuclear sap disappear , the chromosome and the spindle fibers connect with each other , and arrange in the surface of the equator.

④anaphase: the centromere detaching ,each pair of chromatids set apart from the equatorial plate to move to the two poles, thereby to compose the independent daughter chromosome respectively.

⑤telophase : the two daughter chromosomes arrive at the two poles , chromosome gradually fall into slender , emerging of the nuclear membrane with nuclear sap again . Meanwhile , divide into two cells in the two poles.

Mitosis

1.Interphase 2-4.prophase 5.metaphase

6-7.anaphase 8.telophase 9.two daughter cells

㈡ amitosis Direct nuclear division and it is most simple

and common type of division . (in lower plant)

㈢ meiosis one especial mitosis , as a result , divide

into four cells in process of sexual reproductive.

Review Questions 一 .Definition Pit , plasmodesmata , protoplast , ergastic

substance 二 .simple answer 1.How about the composing of the cell wall? 2.what are included in cell wall

characteristics? 3.which types has crystal?