Lecture notes in Microbiology

Difference between Prokaryotic & Eukaryotic Transcription

Transcription in Prokaryotes and Eukaryotes

Transcription is a process by which the genetic information present in the DNA is copied to an intermediate molecule (RNA). The sequence in the RNA is complementary to that of the gene which is transcribed and thus the RNA retains the same information as the gene itself. Transcription is a universal process in the living word and it occurs both in prokaryotes and eukaryotes.  Even though the overall process of transcription is similar in both prokaryotes and eukaryotes, there do exists some fundamental differences between these groups.

This post summarizes the overall similarities and differences between the Prokaryotic and Eukaryotic transcription in a detailed but easy way.

Similarities between prokaryotic and eukaryotic transcription

1.      In both groups DNA acts as the template for RNA synthesis

2.      In both groups transcription produces RNA molecule

3.      Chemical composition of transcript is similar in both groups

4.      Transcription is facilitated by the enzyme RNA polymerase in both groups

5.      In both groups, one strand of the DNA duplex acts as the template

Difference between prokaryotic and eukaryotic transcription

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Lecture notes in Microbiology

Prokaryotes Vs Eukaryotes: (Similarities and Differences Between Prokaryotes & Eukaryotes)


Difference between Prokaryotes and Eukaryotes

.Prokaryotes and Eukaryotes are the two fundamental or basic classes of cells. They are mainly distinguished by their size and internal structures. The existence of two classes of cells without any intermediate type represents one of the most fundamental evolutionary separations in the living world. Prokaryotes are structurally and evolutionarily more primitive to eukaryotes. Even though they are two separate classes of living organisms, they share many common characteristics. The shared properties reflect the fact that eukaryotic cells most certainly evolved from prokaryotic ancestors.

Shared common characters of prokaryotes and eukaryotes are as follows:

(1).   Cellular contents in both prokaryotes and eukaryotes are limited by plasma membrane

(2).   In both groups, plasma membrane composed of lipid bilayer with intermittent protein molecules

(3).   DNA is the genetic information carrier in both the groups

(4).   Chemical composition of nucleic acids (DNA and RNA), their structure and their organization are similar in both groups

(5).  Even though the mechanism slightly varies, the process of transcription, translation and DNA replication occurs in both prokaryotes and eukaryotes

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mcq biology

DNA Repair Mechanisms: Biology MCQ 019 with Answer Key (Model Questions for CSIR NET and GATE Life Sciences Examination, December 2015)

MECHANISTIC STUDIES OF DNA REPAIR

1. Which of the following DNA repair mechanism is known as the ‘cut and patch mechanism’?

a.       Photoreactivation
b.      Nucleotide excision repair
c.       Base excision repair
d.      Mismatch repair

2. DNA helicase enzyme involved in base excision repair mechanism is______.

a.       DNA helicase I
b.      DNA helicase II
c.       DNA helicase III
d.      DNA helicase IV

3. In mismatch repair mechanism, which of the following protein recognize DNA mismatches in the genomic DNA?

a.       MutH
b.      MutS
c.       MutL
d.      UvrD

4. The main difference between nucleotide excision repair  (NER) and base excision repair (BER) is:

a.       In NER double strand breaks are repaired where as in BER single strand breaks repaired
b.      NER is a light dependent reaction whereas BER is light independent process
c.       In NER phosphodiester backbone is first cleaved where as in BER phosphodiester backbone is cleaved later
d.      All of these

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Botany lecture notes

Life Cycle in Algae (Haplontic, Diplontic, Haplodiplontic, Haplobiontic and Haplo-diplobiontic Life Cycles)


Life Cycle of Algae

Nature is a machine. The family is a machine. The life cycle is like a machine.

Ray Dalio

What is life cycle?

The growth and development consists of a number of distinct morphological and cytological stages. The sequence of these orderly changes is called as LIFE CYCLE. It is the sequence of all different phases or events through which an organism passes from a diploid zygote of one generation to the zygote of the next generation through haploid gametes.

There are five different types of life cycles in algae based on the number of haploid and diploid generations.

life cycle in algae

Haplontic Life Cycle

1. Haplontic life cycle

2. Diplontic life cycle

3. Haplodiplontic life cycle

4. Haplobiontic life cycle

5. Haplo-diplobiontic life cycle

(1). Haplontic life cycle:

Ø  Most common type of life cycle in algae

Ø  Life cycle is diphasic (two phases)

Ø  The prominent phase is haploid gametophytic phase

Ø  The diploid (sporophytic) phase in the life cycle is represented by the ZYGOTEContinue reading

Botany lecture notes

Algae: General Characters (with Power Point Presentation – PPT)


Important Characteristics of Algae

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“The life of the planet began the long, slow process of modulating and regulating the physical conditions of the planet. The oxygen in today’s atmosphere is almost entirely the result of photosynthetic living, which had its start with the appearance of blue-green algae among the microorganisms”

                                                                     Lewis Thomas, 1984


General appearance of algae

An Algal Bloom of Blue Green Algae

What are algae?

Algae is a group of chlorophyll containing thalloid plants which bear unicellular or multicellular sex organs and the sex organs are NOT protected in the sterile jacket cells. An undifferentiated plant body is known as ‘thallus’. In thalloid plants, there is no differentiation of plant body into true roots, stem and leaves.

The study of algae is known as PHYCOLOGY. The one who study algae is called Phycologist

General characters of algae

Ø  Thalloid plant body

Ø  In Eichler’s system of classification, algae are placed in the Division Thallophyta along with Fungi and Lichens.

Ø  Algae are autotrophs (synthesize food using light energy)

What is thallus?

Spirogyra Thallus *

Ø  Algae differ from fungi in:

⊕. Presence of photosynthetic pigment – chlorophyll
⊕. Mode of nutrition (autotrophs)

Ø  Majority of algae are in aquatic habitat (fresh water or marine), some algae are terrestrial also

Ø  Algae are present in all parts of the world including Arctic and Antarctic regions (universal occurrence)

Ø  Sex organs are unicellular or multicellularContinue reading