Plant Tissue System

Question 1

In what do changed occur in a cell during cell differentiation?

Answer 1

Changes in
Cytoplasm
Organelle
Cell wall

Question 2

What are the three main tissue systems of vascular plants

Answer 2

Dermal tissue system
Ground tissue system
Vascular tissue system

Question 3

What is the outer protective covering if plants

Answer 3

Dermal tissue system

Question 4

What is an example for dermal tissue system

Answer 4

Epidermis

Question 5

What are the characteristics of epidermis

Answer 5

1. Tightly packed single cell layer
2. Protective layer in stems and roots of primary plant body and leaves
3. Normally covered by a cuticle
4. Specialized cells such as guard cells and trichomes and root hairs are found .

Question 6

What is cuticle

Answer 6

A waxy epidermal coating in aerial parts

Question 7

Functions if epidermis

Answer 7

-Defence against pathogens
-Cuticle help prevent water loss
-Root hair involve in absorption of water and mineral ions
-Gaurd cells help in gaseous exchange
*Hair like trichomes reduce water loss
*Shiny hair reflect excess light
*Some trichomes secrete chemicals involved in defence against pathogens/herbivores

Question 8

Epidermis in the older regions of stems and roots are replaced by

Answer 8

Periderm after secondary growth

Question 9

What are trichomes

Answer 9

Epidermal outgrowths such as hairs and glands

Question 10

What is the main function of ground tissue

Answer 10

Fills the gap between dermal tissue and vascular tissue

Question 11

What are the two parts of ground tissue

Answer 11

Cortex
Pith

Question 12

What are the ovations if cortex and pith in relation to the vascular tissue

Answer 12

Cortex - outer to the vascular tissue
Pith - inner to the vascular tissue

Question 13

The ground tissue consists of cells specialized for functions such as

Answer 13

Storage
Photosynthesis
Short distant transport
Support

Question 14

What are the three main types of cells present in ground tissue

Answer 14

Parenchyma cells
Collenchyma cells
Sclerenchyma cells

Question 15

What are the characteristics of parenchyma cells

Answer 15

Living even at functional maturity

Mature cells have primary cell walls(relatively thing and flexible), most cells lack secondary walls

Have large central vacuole

Question 16

What are the functions if parenchyma cells

Answer 16

Perform most of the metabolic functions of the plants

Storage

Most of the parenchyma retain the ability to divide and differentiate under suitable conditions. Wound repair, tissue culture.

Question 17

What are plastids

Answer 17

Some cells in root and stems contain plastids (leaucoplast) which store starch

Question 18

What are the characteristics of collenchyma cells

Answer 18

Generally elongated
Thicker primary cell walls
Walls are unevenly thickened
Living even at functional maturity
Found just below the epidermis of young stems and petioles

Question 19

What is the function of collenchyma cells

Answer 19

Give mechanical support to leaves and stems without restraining growth

Question 20

What are the features if sclerenchyma cells

Answer 20

Have secondary cell wall produced after cell elongation

Secondary cell wall is thickened with large amount of lignin

Dead cells at maturity

Question 21

What are the two types if sclerenchyma cells

Answer 21

Sclereids
Fibres

Question 22

What are the features of sclereids

Answer 22

Shorter and wider than fibres
Irregular shape
Thick lignified secondary cell wall

Question 23

Location of sclereids

Answer 23

Places where growth has stopped

Nut shells
Seed coat
Flesh of coarse fruits

Question 24

Features of fibres

Answer 24

Usually grouped in strands
Long, slender and tapered

Question 25

A use of fibres

Answer 25

To commercially obtain fibres Coconut husk Hemp fibres

Question 26

Function of sclerenchyma

Answer 26

Provide support and strength

Question 27

Xylem consists of

Answer 27

Vessel elements Tracheids Fibres Parenchyma cells In angiosperm and some gymnosperms

Question 28

What mainly conduct water in xylem

Answer 28

Vessel element and tracheids

Question 29

What gives mechanical strength to xykem

Answer 29

Fibres

Question 30

What are the functions of parenchyma in xylem

Answer 30

Storage Radial transportation

Question 31

What types of plants contain vessel element

Answer 31

All angiosperm Some gymnosperms

Question 32

Features of xylem vessel element

Answer 32

Cylindrical and long Wider, shorter and thinner cell walls than tracheids Secondary walls thickened with lignin Perforation plates are found at end walls of vessel elements. Other walls are interrupted by pits. Water flows freely through perforated plates

Question 33

Function of xylem vessel element

Answer 33

Provide support to prevent collapse under tension of water support

Question 34

What plants have tracheids

Answer 34

All vascular plants

Question 35

Features of tracheids

Answer 35

Long thin cells with tapering ends Secondary cell wall thickened by lignin and often interrupted by pits Water moves from end to end by pits Thickening lignin provides support to prevent collapse under water transport

Question 36

What are the components of phloem tissue

Answer 36

Sieve tube elements Companion cells Parenchyma cells Fibres In angiosperm

Question 37

What is the dead cell in phloem

Answer 37

Fibres

Question 38

What are the plants that lack sieve tube element and companion cells

Answer 38

Seedless vascular plants Gymnosperms

Question 39

What do the plants that lack sieve tube elements have instead

Answer 39

Long narrow cells called sieve cells

Question 40

What are the organelles that are absent in sieve tube elements

Answer 40

Nucleus Ribosomes A distinct vacuole Cytoskeletal elements

Question 41

Features of sieve tube elements

Answer 41

Cytoplasm reduced to thin peripheral layer Absence of nucleus, ribosomes , distinct vacuole and cytoskeletal elements Absence of these allows passing of nutrients more freely Chains of sieve tube elements align to form sieve tubes The end walls of between sieve tube element contain porous plate called sieve plate Sieve plate allows movement of fluid from one sieve element to next

Question 42

What is the non conducting cell in phloem

Answer 42

Companion cell

Question 43

Features of companion cells

Answer 43

Non conducting cells Found alongside each sieve tube element and connects with it by numerous plasmodesmata Nucleus and ribosomes of it also serves to adjacent sieve tube element Some companion cells in leaves help with phloem loading and unloading