Secondary growth

Question 0

Secondary growth occurs in

Answer 0

Most Dicot plants

Roots and stem of gymnosperms

Question 1

Lateral meristem is comprised of

Answer 1

Interfascicular cambium
Intrafascicular cambium
Cork cambium

Question 2

Intrafascicular cambium in young dicots is present as

Answer 2

Patches of single layer between xylem and phloem

Later join to form a continuous ring

Question 3

Interfascicular cambium arises due to

Answer 3

De differentiation in cells of medullary Rays

Question 4

Vascular cambial ring is composed of

Answer 4

Inter and Intrafascicular cambia

Question 5

Type of cell division occurring in cambium ring

Answer 5

Periclinal

Question 6

Cambium is more active towards which side

Answer 6

Inner side

So amount of secondary xylem produced is more

Question 7

What happens to primary and sec phloem during continued sec growth

Answer 7

They get crushed due to continuous expansion of cambium ring towards periphery

Question 8

How are sec medullary Rays arranged?

Answer 8

Radially

These conduct food water & minerals from centre to periphery

Question 9

Sec medullary Rays are also called …

Answer 9

Vascular Rays

Question 10

Sec xylem is also c’d

Answer 10

Wood

Question 11

Cambium is very active in which season

Answer 11

Spring

Question 12

Wood formed in spring is called

Answer 12

Spring wood/ early wood

Question 13

Wood formed in winter is called

Answer 13

Autumn wood / late wood

Question 14

Vessels with wider lumen form in

Answer 14

Early wood (spring season)

Question 15

Which is darker in colour:Spring wood/autumn wood?

Answer 15

Autumn wood is darker and has a higher density

Question 16

Growth rings show gradual transition from

Answer 16

Spring wood to autumn wood

The transition from autumn wood to spring wood is sudden

Question 17

One annual ring is composed of

Answer 17

One circle of spring wood and one circle of autumn wood

Question 18

Annual rings cannot be noted in plants of

Answer 18

Tropical areas

As there is uniform temp and rainfall throughout the year

Question 19

What is heartwood?

Answer 19

Older parts of sec xylem that turn dark due to progressive deposition of oil tannin resin etc

This region is no longer involved in conduction but provides resistance and mechanical support to stem

Question 20

In older stems water conduction is mainly carried out by

Answer 20

Sapwood

Question 21

Thickness of sapwood

Answer 21

Remains almost same

Question 22

Cork cambium is also called as

Answer 22

Phellogen or extra stelar cambium

Question 23

Stele comprises

Answer 23

All tissues inner to endodermis ( pericycle, vascular bundle and pith )

Question 24

Outer cells of phellogen differentiate to

Answer 24

Phellem or cork

Question 25

Inner layer of phellogen forms

Answer 25

Phelloderm or secondary cortex

Question 26

Mature cork cells have thick cell walls due to deposition of

Answer 26

Suberin (so is impervious to water) Young cells have thin cellulosic cell walls

Question 27

Cells of phelloderm are

Answer 27

Living with parenchymatous cells

Question 28

Phellogen phellem and phelloderm are collectively called

Answer 28

Periderm

Question 29

Cork cambium is responsible for

Answer 29

Sec growth in cortex region

Question 30

Activity of cork cambium is required due to

Answer 30

Rupture of epidermis and cortex because of the activity of vascular cambium

Question 31

What is bark?

Answer 31

All tissues outside the vascular cambium | Periderm,pericycle,sec phloem,pri phloem,

Question 32

Types of bark

Answer 32

Early /soft bark | Late/ hard bark

Question 33

Ring bark is found in | Bark separates as continuous sheets

Answer 33

Beula(bhoj patra)

Question 34

Scale barks are found in | Cork cambium separate as small flakes or scales

Answer 34

Guava

Question 35

The superficial covering of tree trunk that separates off annually is called

Answer 35

Bark

Question 36

Thin walled loose parenchymatous cells produced due to increased activity of phellogen are called..?

Answer 36

Complementary cells

Question 37

How are lenticels formed?

Answer 37

Due to rupture in epidermis as no.of complementary cells increases

Question 38

Lens shaped openings on the bark are called

Answer 38

Lenticels

Question 39

Lenticels are also called

Answer 39

Breathing pores

Question 40

Arrangement of vascular bundles in dicot roots is

Answer 40

Radial with exarch xylem

Question 41

Cambium is completely secondary in origin in..

Answer 41

Dicot roots

Question 42

Cambium strips in dicot root form a ring due to cell division in

Answer 42

Pericycle cells lying just above the protoxylem

Question 43

Position of wavy cambium ring of dicot root wrt xylem and phloem

Answer 43

Above the xylem but below phloem

Question 44

Vascular cambium in roots originates from tissues of

Answer 44

Region just below phloem bundle and a part of pericycle tissues

Question 45

The result of secondary stellar growth in roots is formation of

Answer 45

A central sec xylem surrounded by sec phloem

Question 46

Cork cambium arises due to divisions in cells of

Answer 46

Pericycle

Question 47

Balloon like swellings of xylem parenchyma in the lumen of vessels of the heartwood are called

Answer 47

Tyloses(tracheal plugs)

Question 48

Lateral meristem gives rise to

Answer 48

Secondary tissues

Question 49

Study of ageing is

Answer 49

Gerontology