Botany lecture notes

Difference between Phellem and Phelloderm

Phellem vs Phelloderm

Phellem vs Phelloderm
(Similarities and Differences between Phellem and Phelloderm)

During the secondary growth in both stem and root, the peripheral tissues like epidermis, hypodermis and cortex are replaced by a new secondary tissue called the Periderm (bark). The periderm composed of three components: (1) Phellogen, (2) Phellem and (3) Phelloderm.

(1). Phellogen: Phellogen is the cork cambium, a layer of meristematic tissue which produces the phellem and Phellogen together known as the periderm or bark.

(2). Phellem: Phellem is the actual cork, produce by the phellogen towards the outer side.

(3). Phelloderm: Phelloderm is the secondary cortex, produced by the phellogen towards the inner side.

Even though the phellem (cork) and phelloderm (secondary cortex) are produced by the same meristematic tissue (phellogen), they show many differences. The current post discusses the Similarities and Differences between the Phellem and Phelloderm with a Comparison Table.

Similarities between Phellem and Phelloderm

Ø  Both phellem and phelloderm are secondary tissues.

Ø  Both are produced by the cork cambium – phellogen.

Ø  Both are parenchymatous cells.

Ø  Both form the component of bark.

Difference between Phellem and Phelloderm

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Botany lecture notes

Difference between Primary and Secondary Meristem


Primary vs Secondary Meristem in Plants

Primary Meristem vs Secondary Meristem
(Similarities and Differences between Primary and Secondary Meristem)

Meristems are a group of plant cells that remain in a continuous state of division. The meristematic cells continuously produce new cells through the life of the plant. In previous posts, we have discussed the Characteristics of Meristematic Cells, Classification of Meristems and Difference between Meristematic and Permanent Tissues. Meristems are classified into different categories based on different criterions. In one such classification, the meristems are classified into two groups based on the nature of cells giving them. These two groups are (1) Primary Meristem and (2) Secondary Meristem.

(1). Primary Meristem: Primary meristems are the direct descendants of the embryonic cells. They continuously involved in the cell division and growth process of the plant. Example: apical meristem of shoot apex and root apex.

(2). Secondary Meristem: Secondary meristems are the meristematic tissue arises from the permanent tissues. Secondary meristems are usually lateral meristems and are responsible for the increase in thickness of the plant. Example: vascular cambium and cork cambium (phellogen).

The present post describes the Similarities and Differences between the Primary Meristem and Secondary Meristem.

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Botany lecture notes

Anatomical Difference between Stem and Root


Anatomical Difference between Shoot and Root

Anatomical Difference between Stem and Root
(Stem Anatomy vs Root Anatomy)

Stem: Stem is the part of the plant which lies above the surface of the soil. It arises from the plumule of the embryo. Stem shows positively phototropic and negatively geotropic growth. Stem possess nodes and internodes. Branches, leaf, flower bud and bracts are developed from nodes.

Root: Root is the part of the plant which lies below the surface of the soil. It arises from the radical of the embryo. Root shows positively geotropic and negatively phototropic growth. Root is not differentiated into nodes and internodes.

The present post summarize the anatomical difference between the Stem and Root with a Comparison Table.

Plant Anatomy Diagram Dicot Stem

Anatomical Difference between Stem and Root

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Botany lecture notes

Anatomical Difference between Shoot Apex and Root Apex


Difference between shoot and root apex

Shoot Apex vs Root Apex
(Anatomical Difference between Shoot Apex and Root Apex- A Comparison Table)

Apex is the growing terminal portions of the stem and roots in plants. The apical portion of the stem is called ‘Shoot Apex’ and that of the root is called ‘Root Apex’. The apex portions of both stem and root possess a meristematic tissue called the ‘Apical Meristem’. The shoot apex and root apex shows considerable differences both in their external features (morphology) and internal features (anatomy). The present post discusses the anatomical similarities and differences between a shoot apex and a root apex with a comparison table.

Similarities between Shoot Apex and Root Apex

Ø  Both shoot apex and root apex are the growing terminal regions.

Ø  Both contain apical meristem.

Ø  The tissue in both shoot and root apex are primary tissue.

Difference between Shoot Apex and Root Apex

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Lecture notes in Microbiology

Difference between Prokaryotic and Eukaryotic Chromosome – A Comparison Table


Prokaryotic Chromosome vs Eukaryotic Chromosome

Prokaryotic Chromosome vs Eukaryotic Chromosome
(Similarities and Differences between the Chromosomes of Prokaryotes and Eukaryotes)

Prokaryotes and Eukaryotes are the two major domains of living organisms. This classification is on the basis of the features of their cellular features primarily the nature of membrane bounded organelles and organization of the genetic materials. Both prokaryotes and eukaryotes contain the genetic materials which are organized into specialized structures called Chromosomes. Even though the term chromosome is accurate only for eukaryotes, the genetic materials of prokaryotes are also described as prokaryotic chromosome. The prokaryotic chromosome is considerably different from that of eukaryotes. The present post describes the Similarities and Differences between the Prokaryotic Chromosome and Eukaryotic Chromosome with the help of a Comparison Table.

Similarities between Prokaryotic and Eukaryotic Chromosomes

Ø  The chromosome of both prokaryotes and eukaryotes contains the genetic material DNA.

Ø  The chemical composition and structural organization of DNA is similar in both prokaryotes and eukaryotes.

Ø  In both prokaryotes and eukaryotes, the expression of genetic material is facilitated by transcription and translation.

Ø  In both groups, the negatively charged DNA interacts with some positively charged proteins to nullify their charges.

Ø  The genetic material contains both coding and noncoding sequences.

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