There are various layers of cells in the root. The cortical layer which is present on the innermost side is called as endodermis. The cells of endodermis are barrel-shaped. These cells are closely packed, suberized and its thickening is called as casparian strips. There are certain cells which are not suberised called as passage cells

• Tracheids are elongated, narrow tube-like cells with thick lignified walls with large cell cavity. 
• They have pointed and tapering ends. They are dead empty cells with pits on their walls. They do not have perforations. 
• Vessels are the tubular structure. The vessel members are connected by means of plates with pores and are known as perforation plates through which water moves upward. 
• These are perforated cells. Xylem parenchyma cells are made up of thin cellulosic walls. Xylem is a complex tissue that has highly thickened walls and obliterated central lumen. 
  So, the correct option is A.

• The arrangement in which the protoxylem lies outside and metaxylem lies inside is called exarch. 
• On the basis of number of protoxylem group, roots can be divided into monarch, diarch, triarch, tetrarch or polyarch.
•  In monocot roots, exarch is found in the polyarch condition i.e many protoxylems (12-20) alternating with phloem.
  So, the correct option is C. 

• The root epidermis is made up of two types of cells, trichoblasts, and atrichoblasts. 
• Trichoblast cells which are produced by the division of protoderm form tubular outgrowths called root hairs. 
• These root hairs are involved in the process of absorption and encouragement. 
• Thus, the correct option is D.

• Sclerenchyma is a simple permanent tissue that has lignified walls. It provides mechanical strength and stiffness to the plant. It forms the outer coating of nuts. It is mainly composed of dead cells.
• Collenchyma provides flexibility and bending capability to the stem.
• Parenchyma is a living tissue that is used for food storage, conduction, etc.
• Aerenchyma are parenchymatous cells that provide buoyancy.

C. Vascular bundles are collateral.

Vascular bundles in monocot stems are scattered in ground tissue. Each vascular bundle is conjoint, Collateral, endarch and closed. They are skull shaped. 

• Cotton clothes are made up of thin fibers which are linked by the cellulosic units. 
• The cells of cambium are present in cotton clothes. There are thin-walled meristematic cells in the cambium which have no lignin deposition. 
• This allows the cotton clothes to be soft and comfortable. 
• Thus, the correct answer is option A. 

Xylem and phloem are collectively referred to as vascular bundles. Xylem carries the water and minerals from the soil to different parts of the body. It consists of xylem vessels, xylem tracheids, xylem parenchyma, and fibers. Phloem consists of sieve tubes, companion cells, phloem fibers, and phloem parenchyma cells and helps in translocation of sugar from leaves to other parts of the plants.

Collateral vascular bundles are characterized by xylem and phloem are lying on the same radius with the xylem located towards the center and phloem located towards the periphery. It is present in a stem.

D. All of the above

Dicot

According to concept / hypothesis of stele, proposed by Van Tiegham, the primary body of root and stem are anatomically same, i.e., consist of a central stele surrounded by cortex. 

Pith is large and well developed in dicot stem and monocot root which is made up of thin walled colourless parenchymatous cells with lot of intercellular spaces.

The lenticels are the small openings in the bark of plants for gaseous exchange. The lenticel phellogen gives rise to a large mass of cells called the complementary cells. These cells are centrifugally and loosely arranged. These cells are parenchyma cells and are non-chlorophyllous. Hence they do not perform photosynthesis. Thus the correct answer is option A.

A) Dendrology is the scientific study of trees.
B) Dendrochronology is the scientific method of the dating of tree rings.
C) Chronology is the method of arranging dates or event in the way they occur.
D) Chorology is the study of a geographical phenomenon occurring in a particular region.
So the correct option is 'Dendrochronology'

Bicollateral vascular bundles are where xylem is present in the middle of two phloem strands. It is a type of conjoint vascular bundle.

• In Carissa,  the thorns are modifications of apical or terminal buds. 
• The apical bud is the primary growing point located at the apex (tip) of the stem.
  

In mature monocot roots, after the loss of epidermis, the outer cells of general cortex are suberised become thick-walled layer called exodermis.

So, the correct option is ‘Monocot root’.

• The axillary bud is also known as a lateral bud.
• It is situated at the region where the leaf petiole gets attached to the stem
• These buds are capable to form shoots, it can form vegetative shoots (stems and branches) or reproductive shoots (flowers).
  
• The terminal bud is also known as apical bud which is the primary growing point situated at the tip of the stem which forms the dominant bud.
  
• The terminal bud can make the lateral buds dormant (apical dominance).
• Both the buds are formed by the activity of shoot apical meristem.
• So, the correct answer is 'Apical meristem'.

• The quiescent centre is that part of the root-promeristems that contains the initials of epidermis, cortex and stele.
  
• These cells divide less frequently as they are inactive and are present at the pole of cortex and stele.
  
• The cells with QC have small dictyosomes, nuclei and nucleoli with little cytoplasm.
  
• These cells also have little endoplasmic reticulum, mitochondria and contain low concentrations of RNA, DNA and protein than the other cells of the root apex.
  
• So, the correct answer is 'Low'.

Shoot apical meristem occurs over the tip of the plumule.

In 1953, during the course of analysing the organization and function of the root apices, Frederick Albert Lionel Clowes (born 10 September 1921), at the School of Botany (now Department of Plant Sciences), University of Oxford, proposed the term 'cytogenerative centre' to denote 'the region of an apical meristem.

Pericycle is the outermost part of the stele. It is made up of parenchyma tissue. Its function is a formation of lateral roots in both dicot and monocot roots.

So, the correct option is ‘Parenchyma cells’.

In dicotyledonous stems, during intra stelar secondary growth, intra fascicular cambium(primary meristem) and inter fascicular cambium(secondary meristem) joins together and form into a ring of cambium is called vascular cambium. It is partly primary meristem and partly secondary meristem. Its activity is continuous and uninterrupted. Due to the seasonal influence, it produces two types of secondary xylems, spring wood and autumn wood. Both these woods, together form into a ring of wood called annual ring or growth ring. Every 

annual ring becomes sap wood and every sap wood gradually transform into heart wood. Due to these transformations amount of heart wood increases.

so, the correct option is 'Activity of vascular cambium due to seasonal variations'.

The non-vascular strips developed radially in the secondary vascular tissues are called vasculary rays or secondary medullary rays. These are multiseriate, homo or heterocellular. Each vascular ray is a combination of xylem ray and phloem ray.

So, the correct option is ‘Dicot stems’.

Endodermal cells without casparian thickenings are called passage cells. These are present opposite to the protoxylem.

So, the correct option is ‘Endodermis’.

Dicot root differs from monocot root in the activity of pericycle, no.of xylem strands, the presence of medulla and the activity of conjunctive tissue. In dicot root, pericycle is involved in secondary growth, 2 to 4 vascular bundles are present, and small pith as compared with monocot root.

So, the correct option is ‘fewer number of radial vascular bundles with small pith’.

Based on the relative position of xylem and phloem, the vascular bundles are classified into:

The small strip of cambium formed between the vascular bundles in dicot stem is called interfascicular cambium. It is formed by the dedifferentiation of parenchyma present in the medullary rays.

So, the correct option is ‘Between vascular bundles’.

A. Dermal tissue system – Epidermis 

B. Vascular tissue system – Xylem and phloem 

C. Ground tissue system – General cortex, endodermis, pericycle,medulla,      medullary rays, conjunctive tissue, mesophyll 

D. Epidermal tissue system – Epidermis

So, the correct option is ‘Ground tissue system’.

A. Periderm - During secondary growth in both dicot stem and root, multilayered or cellular complex tissue formed in the region of cortex is called Periderm. It is formed towards the outer side of the stem or root.

B.Epiblema – Epidermis with root hairs is called Epiblema.

C. Phelloderm – the parenchymatous formed towards inner side of the cork cambium is called phelloderm or secondary cortex.

D. Phellogen – a ring of meristematic tissue formed by the dedifferentiation of parenchyma present in the general cortex of dicot stem or root is called Phellogen or cork cambium.

So, the correct option is ‘Periderm’.

In dicot stem during secondary growth, the oldest part of xylem situated towards outer to the medulla and oldest phloem is situated just towards inner to the primary cortex.

So, the correct option is ‘Inner to primary cortex’.

In the endodermal cells, lingo-suberised thickenings are present on the radial and tangential cell walls. These are called Casparian strip. Due to this, endodermis acts as biological check post and prevent wall to flow of materials.

So, the correct option is ‘Casparian strips’.

A. Monocot stem – medullary rays are absent.

B. Dicot stems – medullary rays are present

C. Young dicot root – medullary rays are absent.

D. Old dicot root – medullary rays are extra prominent. It is due to the occurrence of secondary growth.

So, the correct option is ‘Old dicot root’.

In dicot stem, during secondary growth, when new secondary xylem formation is going on, oldest secondary xylem appear outside the primary xylem.

In the endodermal cells, lingo-suberised thickenings are present on the radial and tangential cell walls. These are called Casparian strip.

So the correct option is ‘Ligno-suberised band running in endodermal cell walls.

A.Pea – three xylem strands are present.

B.Sunflower – four xylem strands are present.

C.Ficus – more than six xylem strands are present.

D.Ranunuculus – four xylem strands are present.

So, the correct option is ‘Ficus’.

In the old dicotyledonous stems, after secondary growth, all tissue present outside of the vascular cambium (periderm + secondary phloem) constitute bark.

So, the correct option is ‘All tissues outside the vascular cambium’.

A. Dicot leaf – Mesophyll is the ground tissue. It is differentiated into palisade and spongy parenchyma.

B. Monocot leaf – Mesophyll is the ground tissue. It is not differentiated. It shows only spongy parenchyma.

C. Cortex is the ground tissue in dicot stem. It is differentiated into hypodermis, general cortex and endodermis.

D. Monocot stem – the region present inner to the hypodermis is ground tissue. It shows scattered arrangement of vascular bundles.

So, the correct option is ‘Dicot stem’.

Vascular bundles in which two phloem patches one xylem strand are present on the same radius are called Bicollateral vascualar bundles. In these bundles, phloem present towards outer side is called outer phloem and inner side is called inner phloem. Between xylem and phloem two cambium strips are present. These are found in Cucurbitaceae and Solanaceae members.

So, the correct answer is 'Bicollateral bundles arranged in two alternate rings'.

A.Dicot root – phloem parenchyma is present.

B.Dicot leaf – Phloem parenchyma is present.

C.Monocot stem – phloem parenchyma is absent.

D.Dicot stem – Phloem parenchyma is present.

So, the correct answer is 'Monocot stem'.

A. Cork cambium – a ring of meristematic tissue or cambium formed by the dedifferentiation of parenchyma present in the general cortex.

B. Vascular cambium – a ring meristematic tissue or cambium, formed by the association of intra and interfascicular cambium.

C. Intercalary meristem – it is a type of meristem present between the permanent tissues of stem apex of grasses.

So, the correct option is – ‘Both A and B’.