Overview of Kingdom Monera

Questions and Answers

What is a primary feature of plasmids in bacteria?

They replicate only during sexual reproduction.

They are membrane-bound organelles.

They are found in all bacteria types.

They assist in antibiotic resistance. (correct)

Which method of bacterial reproduction is considered asexual and occurs during unfavorable conditions?

Spore formation (correct)

Binary fission

Conjugation

Transduction

What role do gas vacuoles play in bacteria?

They store genetic material.

They breakdown nutrients.

They aid in buoyancy. (correct)

They are involved in protein synthesis.

Which of the following are known to undergo transformation?

Streptococcus pneumoniae Signup and view all the answers

What are ribosomes primarily responsible for in prokaryotic and eukaryotic cells?

Protein synthesis Signup and view all the answers

During which process would a plasmid be transferred through longer pili?

Conjugation Signup and view all the answers

Which term describes the storage of substances in bacteria in an insoluble form?

Inclusion bodies Signup and view all the answers

What type of bacteria use water as their primary source of oxygen?

Oxygenic bacteria Signup and view all the answers

What role does the glycocalyx serve in bacterial structure?

Provides protection from white blood cells Signup and view all the answers

Which characteristic distinguishes Gram positive bacteria from Gram negative bacteria?

Thicker cell wall Signup and view all the answers

What is the function of pili in bacterial cells?

Facilitates genetic transfer of material Signup and view all the answers

What is the primary difference between flagella and fimbriae?

Flagella enable movement, while fimbriae help with attachment. Signup and view all the answers

Which type of bacteria lacks a flagella and is considered non-motile?

Nostoc Signup and view all the answers

What is the primary role of mesosomes in bacterial cells?

Control of ATP production Signup and view all the answers

Which statement correctly describes the nucleoid in bacterial cells?

Holds double circular DNA Signup and view all the answers

How does penicillin exert its effect on bacteria?

Destroys cross-linking in the cell wall Signup and view all the answers

Study Notes

Kingdom Monera Overview

Bacterial structure is simple, yet behavior is complex, with some bacteria being autotrophic (photosynthetic or chemosynthetic).

Bacterial Structure

Cell Envelope: Composed of glycocalyx, either as a slime layer or a capsule, made of mucopolysaccharide and polypeptide, which protects against white blood cells and promotes colony formation.
Penicillin: Targets bacterial cell wall, disrupting cross-linking, leading to bacterial death.
Gram Positive Bacteria: Thicker cell walls, retain crystal violet stain (e.g., Lactobacillus, Clostridium, Streptomyces).
Gram Negative Bacteria: Thinner cell walls, do not retain crystal violet stain (e.g., Rhizobium, E. coli, Cyanobacteria, Mycoplasma) and possess porins, pili, and toxins.

Fluid Mosaic Model

Contains hydrophilic heads and hydrophobic tails along with extrinsic, intrinsic, and tunnel proteins.

Mesosomes

Functions similarly to mitochondria, controlling ATP production; invaginations of the plasma membrane that can be vascular, lamellar, or tubular.
Involved in respiration, DNA replication, cell division, and secretion.

Pili, Fimbriae, and Flagella

Bacterial flagella are made of flagellin protein, differing from tubulin.
Pili: Tubular structure made of pilin protein; fewer in number, assists in genetic material transfer.
Fimbriae: Bristle-like, more numerous, primarily aid in bacterial attachment.
Non-motile bacteria: Mycoplasma, Nostoc, and Coccus lack flagella.

Nucleoid and Genetic Material

Nucleoid: Contains double circular DNA (single false chromosome) with non-histone proteins, crucial for DNA packaging.
Plasmids: Extra chromosomal double circular DNA; self-replicating and not present in all bacteria, often confer antibiotic resistance.

Ribosomes and Polyribosomes

Ribosomes are non-membrane bound organelles found in both prokaryotes and eukaryotes; they may form polyribosomes when multiple ribosomes assemble around a single mRNA strand for protein synthesis.

Inclusion Bodies

Storage of substances in bacteria, such as glycogen granules (carbohydrate), volutin granules (phosphate), and sulfur granules (sulfur).
Gas vacuoles found in cyanobacteria, green sulfur bacteria (GSB), and purple sulfur bacteria (PSB).

Bacterial Nutrition

Heterotrophic bacteria can be saprophytic or parasitic; examples include:
- Lactobacillus (produces antibiotics)
- Citrus canker (plant disease)
- Pathogens causing typhoid, tetanus, and cholera.
Symbiotic Bacteria: Rhizobium and Frankia.
Oxygenic Bacteria: Utilize H2O (examples: Cyanobacteria, Nostoc, Anabaena).
Anoxygenic Bacteria: Use H2S as a source (examples: GSB, PSB).

Reproduction

Asexual Reproduction:
- Favorable conditions: Binary fission.
- Unfavorable conditions: Spore formation; endospores composed of calcium dipicolinate.
Sexual Reproduction:
- Primitive DNA transfer methods include:
  - Conjugation: Transfer of plasmid through pili.
  - Transformation: Uptake of naked DNA from the environment (example: Streptococcus pneumoniae).
  - Transduction: Transfer of genetic material through bacteriophages.

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Description

This quiz explores the fundamental concepts of Kingdom Monera, focusing on bacterial structure and behavior. It covers the differences between gram-positive and gram-negative bacteria, as well as key components like the cell envelope and fluid mosaic model. Test your knowledge of bacterial characteristics and the implications of antibiotics like penicillin.