Bacterial Characteristics and Environments Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following characteristics is true about Gram-positive bacteria?

They can photosynthesize like cyanobacteria.

They do not cause diseases.

They have an outer membrane that protects them from antibiotics.

They are more receptive to antibiotics than Gram-negative bacteria. (correct)

What is a common environment for methanogens to thrive?

Underwater in coral reefs.

In oxygen-free environments like thick mud. (correct)

In extremely salty lakes.

In highly acidic soil.

Which type of bacteria is responsible for causing Lyme Disease?

Halophiles

Chlamydia

Cyanobacteria

Spirochetes (correct)

What type of cell shape do bacilli bacteria have?

Rod shaped (D) Signup and view all the answers

What type of environment do thermophiles prefer?

Extremely high temperatures, such as hot springs (D) Signup and view all the answers

What is a primary characteristic of gram-positive bacteria?

They have a thick peptidoglycan layer. (B) Signup and view all the answers

Which type of bacterium requires a constant supply of oxygen?

Obligate aerobes (C) Signup and view all the answers

What process involves the transfer of genetic material between two bacteria?

Conjugation (C) Signup and view all the answers

Which mode of nutrition utilizes inorganic chemicals as an energy source?

Chemoautotroph (D) Signup and view all the answers

What is the defining feature of endospores in bacteria?

They are a type of dormant spore. (D) Signup and view all the answers

What is a defining characteristic of a virus compared to a cell?

Viruses have a DNA or RNA core. (A) Signup and view all the answers

Which component is NOT found in viruses?

Cytoplasm (B) Signup and view all the answers

What distinguishes active immunization from passive immunization?

Active immunization leads to the body developing memory against pathogens. (C) Signup and view all the answers

Which of the following is true about bacteriophages?

They specifically infect and destroy bacteria. (B) Signup and view all the answers

Which statement is true regarding viruses' ability to respond to environmental changes?

Viruses do not respond to environmental changes. (B) Signup and view all the answers

The Tobacco Mosaic Virus primarily infects which type of organism?

Plants (B) Signup and view all the answers

What is the role of antigens in the viral structure?

They help the virus bind to host cell receptors. (A) Signup and view all the answers

What effect does passive immunization have on the immune system?

It provides immediate but temporary immunity. (B) Signup and view all the answers

What is the primary ecological role of saprophytic bacteria?

Recycling nutrients by decomposing dead organic material (D) Signup and view all the answers

Which of the following is NOT a human use of bacteria?

Infection prevention (C) Signup and view all the answers

How do saprophytic bacteria contribute to the ecosystem?

By decomposing dead materials and recycling nutrients (A) Signup and view all the answers

Which bacteria are primarily involved in nitrogen fixation?

Rhizobium (D) Signup and view all the answers

What role do bacteria play in sewage treatment?

Breaking down complex compounds in waste (B) Signup and view all the answers

What is one way bacteria can cause disease?

By releasing harmful toxins (C) Signup and view all the answers

Which process uses bacteria to extract metals from ores?

Bioleaching (C) Signup and view all the answers

What type of bacteria is used in the production of cheese and yogurt?

Lactobacillus (C) Signup and view all the answers

Which type of protists are collectively known as 'zooflagellates'?

Animal-like Protists from Phylum Zoomastigina (A) Signup and view all the answers

What characteristic is unique to members of Phylum Sarcodina?

Use of pseudopods for movement and feeding (B) Signup and view all the answers

Which organism is a well-known representative of Phylum Ciliophora?

Paramecium (A) Signup and view all the answers

Which of the following diseases is caused by a member of Phylum Sporozoa?

Malaria (B) Signup and view all the answers

What do members of Phylum Euglenophyta have that distinguishes them from other plant-like protists?

Two flagella and chloroplasts (C) Signup and view all the answers

What classification applies to the organisms responsible for Lyme Disease?

Bacterial diseases (C) Signup and view all the answers

Organisms in the Phylum Chrysophyta are primarily known for which of the following?

Producing silicon-rich cell walls (B) Signup and view all the answers

Which bacterial disease is NOT typically associated with viral infections?

Tuberculosis (D) Signup and view all the answers

What is the main purpose of herd immunization?

To protect non-vaccinated individuals through community immunity. (C) Signup and view all the answers

Which of the following represents the Herd Immunity Threshold for measles?

92-95% (A) Signup and view all the answers

Which component is NOT part of the immune system's first line of defense?

B cells (A) Signup and view all the answers

What stage follows the 'Entry' stage in HIV infection?

Replication (A) Signup and view all the answers

What is the primary outcome of a lytic infection?

The infected cell is destroyed. (D) Signup and view all the answers

Which method is NOT a type of viral transmission?

Remote contact (C) Signup and view all the answers

What occurs during the assembly stage of a lytic infection?

New viral particles are formed (C) Signup and view all the answers

In viral transmission, what does 'fomite' refer to?

A contaminated surface that transmits the virus (A) Signup and view all the answers

Study Notes

Viruses

Viruses are non-cellular, infectious particles.
Their size ranges from 20 nm to 400 nm.
They are composed of nucleic acids (DNA or RNA), proteins, and sometimes lipids.

Viral Structure - Animal

Nucleic acid core: Made of either DNA or RNA.
Capsid: A protective protein coat surrounding the core.
Antigens: Proteins identifying and binding to host cell receptors.
Envelope: An outer membrane fusing with the host cell during infection.

Viral Structure - Bacteriophage

Bacteriophages are viruses infecting and destroying bacteria.
They have two main regions:
- Tail: Includes a tail sheath and tail fibers.
- Head: Contains the capsid and DNA core.

Viral Structure - Plant

Plant viruses, like Tobacco Mosaic Virus (TMV), cause mosaic patterns on leaves.
They have a simple structure: RNA core and capsid proteins.

Viruses vs. Cells

Characteristic	Virus	Cell
Structure	DNA or RNA core, protein capsid, sometimes envelope	Cytoplasm, nucleus
Reproduction	Only within a host cell	Sexually or asexually
Genetic code	DNA or RNA	DNA
Growth & development	No	Yes
Obtain and use energy	No	Yes
Respond to environment	Yes	Yes
Change (evolve) over time	Yes	Yes

Immunization

Active immunity:
- Natural: Infection
- Artificial: Vaccination - injection with weakened pathogen
Passive immunity:
- Natural: Maternal antibodies
- Artificial: Injection of antibodies (e.g., after animal bite)

Herd Immunity

Herd immunity occurs when enough individuals are vaccinated to protect the rest.
Specific herd immunity thresholds vary by disease.

Immune System Defences

1st Line: Skin barrier, mucus membranes, mucus/saliva/tears, sweat.
2nd Line: Inflammatory response, phagocytic white blood cells, fever, interferon.
3rd Line: B cells, plasma cells, memory B cells, antibodies, helper T cells, killer T cells.

HIV Infection

Stages: Attachment, Entry, Replication, Biosynthesis, Assembly, and Release.

Lytic and Lysogenic Life Cycles of Bacteriophages

Lytic cycle: The phage DNA takes over the host cell, causing its destruction.
Lysogenic cycle: The phage DNA integrates into the host cell's DNA and reproduces along with the cell without killing the cell.

Lytic Infection

Stages: Attachment and injection of phage DNA, replication of viral DNA, biosynthesis and assembly into new phages, and lysis of the host cell.

Lysogenic Infection

Stages: Attachment and injection of phage DNA, circularization or integration into host DNA, reproduction of host cells along with phage DNA(prophage).

Viral Transmission

Direct physical contact: Touching, sexual contact, bloodborne.
Indirect physical contact: Contaminated surfaces (fomites).
Droplet contact: Coughing or sneezing.
Airborne transmission: Virus suspended in air.
Fecal-oral transmission: Through contaminated food or water.
Vector transmission: Animal transmitting the virus to another animal.

Pandemics

Pandemics are widespread outbreaks of infectious diseases.

20th Century Flu Pandemics

Listed the major influenza pandemics of the 20th century, including the strains involved and approximate death tolls.

H1N1 Pandemic (2009)

Described the A/H1N1 virus (swine flu) and its transmission
Includes symptoms associated with the pandemic.

Kingdom Monera

Kingdom Monera comprises single-celled prokaryotic organisms collectively known as bacteria.

Archaebacteria

Archaebacteria are a group of bacteria that thrive in extreme environments.
Some examples include methanogens (methane producers), halophiles (salt-loving bacteria), and thermophiles (heat-loving bacteria).

Eubacteria Types

Proteobacteria: A diverse group of Gram-negative bacteria, including several pathogens.
Gram-positives: Bacteria more sensitive to antibiotics due to the absence of an outer membrane.
Cyanobacteria: Perform photosynthesis and can form algal blooms.
Spirochetes: Corkscrew-shaped bacteria causing diseases like Lyme disease and syphilis.
Chlamydia: Obligate intracellular parasites.

Identifying Bacteria

Methods include examining cell shape, cell organization, cell wall composition, motility, nutrition and energy requirements, oxygen requirements, reproduction, and colony appearance.

Kingdom Protista

Kingdom Protista includes single-celled eukaryotic organisms.
Animal-like protists are categorized into Zoomastigina (flagellates), Sarcodina (amoebas), Ciliophora (ciliates), and Sporozoa (parasites).

Plant-like Protists

Euglenophyta: Plant-like protists with chloroplasts and flagella, and sometimes an eyespot.
Chrysophyta: Plant-like protists like diatoms with silica-rich cell walls.
Pyrrophyta: Plant-like protists such as dinoflagellates, some are bioluminescent, others cause harmful blooms.

Fungi-like Protists

Acrasiomycota: Cellular slime molds.
Myxomycota: Acellular slime molds.

Bacterial Diseases (Examples)

A list of common bacterial diseases.

Controlling Bacteria

Methods of controlling bacterial growth include physical removal, use of antiseptics, disinfectants, proper food storage, food processing, and sterilization.

Preventing & Treating Bacterial Diseases

Preventing bacterial diseases involve vaccination.
Treatment involves antibiotics.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on bacteria with this quiz covering key characteristics of Gram-positive bacteria, environments for methanogens and thermophiles, and the bacteria responsible for Lyme Disease. Challenge yourself with questions about bacterial shapes and ideal habitats.