plant anatomy

Question 1

what is the primary and secondary cell wall made up of

Answer 1

primary= cellulose
secondary= lignin

Question 2

what is the middle lamella

Answer 2

the cementing layer of pectin and calcium between adjoining cells

Question 3

what is the role of the tonoplast

Answer 3

binds the vacuole by a vacuole membrane called the tonoplast

Question 4

what is a meristem

Answer 4

specialist zones of mitosis which produces undifferentiated cells leading to growth and development of plants when the new cells differentiate and form specific tissues

Question 5

what are the different types of meristem

Answer 5

1) apical aka primary
2) intercalary
3) cambium

Question 6

what does the apical meristem do

Answer 6

dividing cells result in increased length of root and shoot tips

Question 7

what does the cambium meristem do

Answer 7

actively dividing cells produce lateral growth therefore increasing girth of the plant

Question 8

what is the intercalary meristem

Answer 8

located at the base of internodes and base of leaves and also, like the cambium, increase girth however are located on mature tissues

Question 9

what is meant when a group of cells are composed of initials and derivatives

Answer 9

cells which remain in the meristem are termed initials and continue to divide as a meristematic cells
cells which are displaced from the meristem, and become a differentiated body cell are called derivatives

Question 10

what does the apical/primary meristem form

Answer 10

forms primary tissues

Question 11

what does the protoderm form

Answer 11

the epidermis

Question 12

what does the ground meristem form

Answer 12

ground tissues

Question 13

what does the procambium form

Answer 13

the primary xylem and phloem

Question 14

what is the ground tissue called in the leaf, stem and root

Answer 14

leaf = mesophyll
stem- cortex and pith
root = cortex

Question 15

what are the different types of ground tissues

Answer 15

1) parenchyma
2) collenchyma
3) sclerenchyma

Question 16

outline what the parenchyma is

Answer 16

• a type of ground tissue found in the cortex, pith and vasuclar rays which is involved in photosynthesis, storage and secretion
• alive at maturity

Question 17

outline what the collenchyma is

Answer 17

• living at maturity with unevenly thickened primary cell walls with great plasticity ideal for strengthening growing tissues and organs
• it is found below the epidermis and in bands next to the vascular bundles

Question 18

outline what the sclerenchyma is

Answer 18

a type of gorund tissue which is elastic and provides strength to mature organs that have stopped grwoing

• the primary cell wall is usually lignified and thick

Question 19

what are the two types of sclerenchyma tissues and what are the differences

Answer 19

fibres
- long and elastoc allowing bending and rentention of normal shape
sclereids
- short and isodiamertic providing hard protective coats

Question 20

what is a xylem

Answer 20

a type of vascular tissue which is dead at maturity and responsible for water and mineral transport as well as mechanical support

Question 21

what is a phloem

Answer 21

cells with living protoplasts at maturity and are responsible for the transportation of photosynthesis products and other organic compounds

Question 22

what does the procambium (primary meristem) give rise to

Answer 22

primary xyelm and phloem

Question 23

outline the structure of xylem vessels

Answer 23

1) in angisperms it is made up of tracheids and vessel elements which are elongated empty cells with lignified secondary cell walls
- vessels have porforations called perforation plates

Question 24

what are pits in xylem

Answer 24

thin areas where the secondary lignified wall is missing allowing water to pass through into trachieds

Question 25

what is the different types of sieve elements in angio and gymnosperms

Answer 25

the conducting cells are sieve elements composed of either sieve cells in gymnosperms or sieve tube members in angiosperms

Question 26

what do sieve areas have

Answer 26

pores which allow protoplasmic connection between adjacent sieve elements

Question 27

what are companion cells

Answer 27

associates with sieve tube members, they are modified paraenchyma cells which regulate translocation of materials

Question 28

what is the epidermis

Answer 28

the outermost layer of the primary plant body which varies in structure and function

Question 29

what are trichomes

Answer 29

appendages of the epidermis which have many functions such as protection, reflection secretion and absorption

Question 30

what is the function of roots

Answer 30

organs specialsed for anchorage, absorption, storage and conduction

Question 31

how does the structure of roots differ in gymnosperms and angiosperms

Answer 31

gym and dicots usually in a taproot system angio= fibrous

Question 32

what does the mucigel sheath and root cap do

Answer 32

protects the developing root

Question 33

what does the primary structure of a root consist of

Answer 33

epidermis, cortex and central stele

Question 34

what is a central stele

Answer 34

made up of vascular tissue and surrounded by a pericyle it is the central part of the root containing the tissues derived from the procambium

Question 35

outline the secondary structure of roots

Answer 35

meristematic activity in of the cambium between the xylem and phloem gives rise to secondary xylem and phloem

Question 36

what are adventitous roots

Answer 36

roots formed later from other places during gorwth and development

Question 37

outline the structure of stems

Answer 37

- stem is an axis with nodes and internodes -leaves produced at the nodes - buds are miantue shoots with dormant apical meristem

Question 38

outline the structure of a leaf

Answer 38

consist of a petiole (stalk) and lamina (blade) sometimes modified with spines or bladders ect made up of primary tisses vasucular tissue in the midrib and viens

Question 39

what ground tissue is the mesophyll made up of

Answer 39

parenchyma tissue

Question 40

what is an abscission zone

Answer 40

comprises of an abscission layere where leaf breaks of as well as a protective layer which preserves the stem

Question 41

what cells make up the secondary xylem and phloem

Answer 41

1) fusiform initials = 2) ray initials

Question 42

what is the difference between fusiform and ray initials

Answer 42

1) fusifrom = undergo periclinal (parallel division) which give rise to secondayr xyelm and phloem 2) ray = periclinal divisons generate parenchyma cells

Question 43

where does the cork cambium arise

Answer 43

the cortex bewlow the epidermis and produces the periderm as cork cells

Question 44

what is the phelloderm

Answer 44

a thin walled inner layer of cells produced by the cork cambium

Question 45

what does the periderm do

Answer 45

the corky outerlayer of a plant stem formed in the seocndary thickening which crushes and replaces hte perimary epidermis and cortex increasing diameter