POL15Q0 Bachelor Of Education Senior Phase And Fet Professional Studies 1Assessment

QUESTION 1

1.1

INTRODUCTION

The unsung heroes of the natural world are bacteria, minuscule creatures that have survived on Earth for billions of years. Despite their little size, they have a significant impact on how ecosystems are shaped, how important processes are carried out, and even how people and other living things feel and function. We shall examine the natural history of bacteria in this article, emphasizing their astounding diversity, ecological importance, and unique interactions with their environment.

Ancient Origins and Evolution It is astounding how long bacteria have existed on Earth. One of the planet's oldest life forms, they can be dating back more than 3.5 billion years. Bacteria have evolved into a huge variety of species through the process of evolution, adapting to a wide range of conditions, from the deep ocean to extreme ecosystems like hot springs and cold landscapes.

Diversity and morphology The diversity of bacteria is enormous, with an estimated 1030 different kinds of bacteria present on Earth. They exhibit an impressive diversity of morphologies, including cocci (spherical), bacilli (rod-shaped), spirilla (spiral-shaped), and filamentous forms. Even certain bacteria, such as spirochetes or bacteria on stalks, have odd shapes and architectures.

Ecological Functions of bacteria are common and can be discovered in almost every ecosystem on Earth. They are essential to the symbiotic interactions, breakdown, and cycling of nutrients. For instance, bacteria are necessary for decomposing organic materials and recycling nutrients so that other species can use them. Additionally, certain bacteria associated with plants in mutualistic relationships aid in nutrient uptake or pathogen defense.

Effect on Human Health, although some bacteria might cause diseases, it is important to understand that the majority of bacteria are not harmful to humans and may even be advantageous. The human microbiome, a term used to describe billions of bacteria found in the human body, is essential to processes including vitamin production, immune system control, and digestion.

Industrial Applications, Bacteria have a wide range of industrial uses, changing industries like biotechnology, agriculture, and medicine. For instance, genetic engineering and fermentation techniques are used to use bacteria to manufacture antibiotics, enzymes, and other useful substances. They are also employed in bioremediation, where they help with environmental clean-up by degrading toxins and pollutants in soil and water.

Resistance to antibiotics, Bacterial adaptation has two cons. Antibiotic-resistant strains have emerged as a result of improper use and overuse, posing a serious hazard to human health. Microbiology faces continual challenges in figuring out the mechanisms underlying antibiotic resistance and creating methods to prevent it.

Looking Ahead, the study of microorganisms is a dynamic and developing science that is always making discoveries and strides. Metagenomics and single-cell genomics are two recent technologies that are shedding light on the enormous genomic variety of bacteria and their roles in complex microbial ecosystems. Furthermore, the prospect of isolating new substances and enzymes from bacteria holds promise for the development of future industrial and medical uses.

In conclusion, the natural history of microorganisms indicates their crucial influence on the environment we live in. These little creatures have altered human health, changed industries, and shaped ecosystems. It is essential for sustainable living and promoting a healthy relationship with the microbial world to comprehend the diversity, ecological significance, and complicated interactions of bacteria. We become more aware of the wonders of the tiny world and their enormous impact as we investigate and unravel the mysteries of microorganisms.

1.2

• The microbe must be present in every instance of the disease: The microorganism under investigation must regularly be discovered in people with the disease but not in healthy people.
• The microbe must be removed from the disease-carrying host and developed in a pure culture: To produce a pure culture that is devoid of any other microorganisms, the microorganism must be isolated from the disease-carrying host and produced in a pure culture.
• The isolated microorganism, when inoculated into a healthy and susceptible host, should be able to reproduce the same disease symptoms noticed in the original infected individual. This is because pure cultures of microorganisms should cause disease when introduced into a healthy, susceptible host.
• The same microbe must be isolated from the newly infected host: To validate their identities and demonstrate a causal link, the microorganisms should be re-isolated from the newly infected host and compared to one another.
• The microbe has to be isolated from the test subject again and proven to be the same as the initial causal agent: To show a direct causal association between the microbe and the disease, the microorganism isolated from the experimentally afflicted host must be the same as the original pathogen.

QUESTION 2

2.1 Examples
Procaryotic cell Bacteria
Eukaryotic Human cell

Differences between human cells and bacteria according to their structure:

• Bacteria have a flagellum while Human cell has no flagella.
• Bacteria have Pili while Human cell has no pili.
• A human cell has a lysosome, Bacteria have no lysosomes.
• A human cell has an endoplasmic reticulum, Bacteria have no endoplasmic reticulum.

Differences between human cells and bacteria according to functions:

• Bacteria are responsible for metabolism, asexual reproduction, and environmental adaptability. While the human cell is responsible for multicellularity, sexual reproduction, and increased complexity.

Differences between human cells and bacteria according to characteristics:

• Bacteria lack a true nucleus, membrane-bound organelles, and it is generally smaller in size. While the human cell has a true nucleus, membrane-bound organelles, and it is larger.

2.2

Influenza virus

Since the influenza virus is covered by an exterior envelope comprised of a lipid bilayer produced from the host cell membrane, it is classified as an enveloped virus. The core viral components are encased in this envelope.

The size of influenza is approximately 80-120 nanometres (nm).

Hemagglutinin (HA) and neuraminidase (NA):

two viral glycoproteins are embedded in the influenza virus' outer membrane. These glycoproteins are essential for viral attachment and host cell invasion.

Matrix Protein:

The virus is structurally supported by the matrix protein layer that lies underneath the envelope.

RNA Genome:

The single-stranded, segmented RNA that makes up the influenza virus serves as its genetic carrier. Different viral proteins are encoded by the RNA segments.

Nucleoprotein (NP):

Ribonucleoprotein (RNP) complexes are created when RNA segments join forces with nucleoproteins. The influenza virus has the RNA polymerase proteins (PA, PB1, and PB2) necessary for the transcription and replication of the viral RNA.

Non-structural Proteins:

In addition to the aforementioned structural elements, influenza.

Bacteriophage T4 virus

A head (capsid) and a tail make up the intricate structure of the bacteriophage T4 virus. The bacteriophage T4 virus is roughly 200 nm long overall, with a head length of 90 nm and a tail length of 115 nm.

Head (Capsid):

The viral genome, which is a double-stranded DNA molecule, is located in the bacteriophage T4's head. The icosahedral form of the skull is made up of structural proteins.

Tail:

The tail is made up of various parts, including:

• The viral genome is injected into the host bacteria by the contraction of the tail sheath, which surrounds the viral tail core.

The viral genome is transported by the tail tube, which extends from the head to the baseplate.

• Baseplate Is affixed to the tail fibers and composed of proteins that bind to and identify certain receptors on the surface of bacteria.
• Tail Fibres Are fibers that extend from the baseplate and are used to recognize and adhere to hosts.
• Tail Pins: These elongated objects that protrude from the baseplate help secure the

QUESTION 3

Bacteriophages, sometimes known as phages, are viruses that attack and proliferate within bacteria. New phage particles are produced as a result of several steps in phage replication. The two main bacterial phage replication cycles are the lytic cycle and the lysogenic cycle.

LYTIC CELL CYCLE

The lytic cycle is a quick and relatively simple process. It entails the following actions:

Attachment:

The phage binds to a vulnerable bacterial cell's surface. particular viral proteins (such as tail fibers or spikes) and receptors on the bacterial cell wall interact to form the attachment, which is often referred to as a particular attachment.

Penetration:

The phage enters the bacterial cell and injects DNA-based genetic material there. In many cases, this procedure requires the phage's tail to contract, which enables the genetic material to pass through the bacterial cell wall and membrane.

Replication:

The phage seizes control of the host's cellular machinery after it has entered the bacterial cell. It starts by synthesizing viral proteins and nucleic acids utilizing the host's resources. The DNA of the phage acts as a model for the creation of new viral genomes.

Assembly:

The newly created viral components, including the viral capsid (protein coat) that encases the genetic material, join together to form complete phage particles.

Lysis:

A huge number of freshly produced phage particles are released into the environment as the bacterial cell is lysed (broken open). The activation of the phage's enzymes, which weaken or break down the bacterial cell wall, frequently aids in this lysis.

Release:

The cycle can then be restarted by the released phage particles infecting more bacterial cells that are vulnerable. The lytic cycle causes the infected bacterial cell to die and lyse while also producing a significant amount of phage offspring.

CIRCLE OF LYSOGENESIS

The lysogenic cycle, in contrast to the lytic cycle, involves integrating the genetic material of the phage into the chromosome of the host bacterium. This creates a solid and long-lasting bond between the phage and the host bacterium. The essential stages of the lysogenic cycle are as follows:

Attachment and Penetration:

Similar to the lytic cycle, the phage attaches to the bacterial cell and injects its genetic material. Instead of instantly taking over the machinery of the host cell, the phage DNA integrates into the bacterial chromosome during the lysogenic cycle.

A phage that has integrated DNA is called a prophage:

It is replicated together with the bacterial DNA during regular cell division and becomes a permanent part of the bacterial genome.

Replication with the Host Cell:

When the bacteria divide, the prophage DNA is faithfully duplicated alongside the host DNA. Vertical transmission of the phage genome occurs as a result of the daughter cells receiving both the bacterium and the integrated phage DNA.

Induction:

Under appropriate conditions, such as exposure to stressors (such as radiation or toxins), the prophage can be urged to leave the bacterial chromosome and join the lytic cycle. This transformation typically results from the activation of specific regulatory genes that are encoded by a phage.

Lytic Cycle Initiation:

The prophage performs the aforementioned steps of the lytic cycle after prophage induction. A new batch of phage particles is reproduced, put together, lysed, and released once the phage DNA has been excised from the bacterial chromosome.

The lysogenic cycle allows the phage to persist in the bacterial population because it delays cell death. The phage can spread horizontally within a population because daughter cells inherit the incorporated prophages.

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