Plant Anatomy

Question 1

Classification of meristematic tissues (origin)

Answer 1

1. Promeristem- apices of embryonic roots and shoots
2. Primary- apical meristems, fascicular cambium, intercalary meristems.
3. Secondary- interfascicular and cork cambium.

Question 2

Classify meristematic tissues (position)

Answer 2

1. Apical - tips
2. Lateral - fascicular and cork cambium
3. Intercalary- leaf base and base of uppermost internodes in monocot stems.

Question 3

Functions of parenchyma

Answer 3

Storage of reserve food

Slow condution of food and water.

Rigidity in succulent plants

Chlorenchyma perform photosynthesis

Buoyancy and aeration of tissues

Question 4

Features of collenchyma

Answer 4

Thickened angles due to pectin and cellulose

Living cells

Absent in monocot stems and root

Found as a complete cylinder below epidermis of young dicot stems, petioles and corners of angular stems

Question 5

Name the two types of sclerenchyma

Answer 5

Sclerenchymatous fibres

Stone or sclerotic cells

Question 6

Give features of xylem tracheid

Answer 6

1. Single enlongated. Tapering
2. Thick cell walls. Lignin. Mechanical strength
3. Thickenings absent - simple or bordered pits which allow water to pass
4. Main vascular tissue in gymnosperms and ferns

Question 7

Features of xylem vessels or tracheae

Answer 7

1. Multicellular. Larger diameter. Prosenchymatous cells joined end to end.
2. Cell wall thickened variously. Lignin
3. Cells connected when septum dissolves

Question 8

Define tyloses

Answer 8

Long protrusions of xylem parenchyma which enter tracheae and block them

Question 9

Features of phloem sieve tubes

Answer 9

1. Non lignified prosenchymatous cells joined end to end
2. Transverse walls have small holes( sieve pits)
3. Cytoplasm vacuolated without nucleus

Adjacent cells remain connected through sieve pits by cytoplasm threads. Direct food transfer

4. Sieve pits grouped into - sieve plates
5. Colorless and insoluble carb- callous. Callus formed over sieve plate.

Question 10

Companion cells

Answer 10

1. Parenchymatous cells adjacent to sieve tubes
   Pteridophyta and gymnosperms- albumen cells
2. Dense cytoplasm. Conspicuous nucleus.
3. Cytoplasmic connection. Nucleus controls activity of sieve tubes and helps in food conduction.

Question 11

On what do the no. And position of stomata depend?

Answer 11

Form of leaf and conditions regard to transpiration

Question 12

What are hairs or trichomes?

Answer 12

Elongation of outer walls of the epidermal cells. May be simple, branched or star shape.

Question 13

Radial vascular bundle features

Answer 13

1. Radial - separate and alternate radii
2. Separated by undifferentiated parenchyma or conjunction tissue
3. Exarch.

Question 14

Concentric vascular bundle types and eg.

Answer 14

Amphicribal or hadrocentric. (Ferns)

Amphivasal or leptocentric( monocot stems)

Question 15

Conjoint vascular bundle types and eg.

Answer 15

Collateral - open ( strip of fascicular cambium present between xylem and phloem) and closed. Monocot and dicot stems.

Bicollateral - phloem present on both sides.
Cucurbitacea or gourd family

Question 16

What are the parts of cortex in ground tissue system

Answer 16

1. Hypodermis - collenchyma in dicots and sclerenchymatous in monocots. Support and strength.
   .
2. General cortex - parenchyma or sclerenchyma.
   Cells of outer layer contain chloroplasts.

3. Epidermis - single layer barrel cells. Living cells which contain starch.
Starch sheath( stems) 
Casparian strip and passage cells ( roots)

Question 17

Functions of cortex

Answer 17

1. Slow movement and storage of food
2. Rigidity to young parts
3. Leucoplasts may be present. Food storage
4. Metabolic functions

Question 18

Functions of pericycle

Answer 18

1. Gives rise to lateral roots and adventitious roots that arise from the stem
2. In dicot roots, gives rise to part of wavy cambium ring for intrastellar secondary growth
3. Mechanical strength and food storage

Question 19

What is the intrastellar ground tissue called

Answer 19

Conjunctive tissue

Question 20

What are the types of cells in the cambium ring?

Answer 20

Fusiform initials

Ray initials

Question 21

Which cells form the inter fascicular cambium

Answer 21

Cells of the pith ray lying between the vascular bundles at the level of the cambium become meristematic and form the strip

Question 22

What forms the secondary vascular bundles

Answer 22

Periclinal divisions of the fusiform intials forms cells toward the periphery and the inner side of the cambium (pith)

Question 23

What forms the secondary medullary rays

Answer 23

The ray initials give rise to parenchymatous cells in a thin narrow band which are arranged radially from the pith to the phloem. These are called the secondary medullary or vascular rays

Question 24

What are the three parts of the periderm

Answer 24

The cork cambium or phellogen formed by the activity of the cells of the hypodermis which become meristematic

The daughter cells on the outer side of the cork cambium called phellem

The cells in the inner side which get cut off and form parenchymatous tissue called phellodern