Monera Flashcards
General characteristics of Monera
- single-celled
- Prokaryotic
- Microscopic
- Carry out respiration
- Binary fission
- Have ribosomes
- Role: Decomposition of dead organisms
- Found everywhere
Name the shapes of Monera
- Coccus/Round
- eg: Streptococcus- causes septic throat - Rods
- eg: Coli- in the colon - Spirals
- eg: Cholera
What are the benefits of bacteria
- Production of yoghurt and cheese
- Manufacturing antibiotics
- Insulin production
- Nutrient recycling
Harmful effects of bacteria
- Can cause disease (Animal- food poisoning Plant- rot)
- Food spoilage (Milk turns sour)
- Tooth decay (Enamel)
Bacterial cell structure
Always present: - Cell wall - Cell membrane - Cytoplasm - Ribosome - Storage granule - Loop of DNA Sometimes present: - Capsule - Flagella - Plasmid
Role of Cell wall in Bacteria
- prevents cell from bursting
Role of Cell membrane in Bacteria
- Selectively permeable
Role of Cytoplasm in Bacteria
- Suspends ribosomes and storage granules
Role of Plasmid in Bacteria
- Cloning vector
- Bacterial resistance
Role of capsule
- Protects from drying out
Role of Flagellum
- Used for movement in search of food
How does Monera carry out sexual reproduction?
Binary fission
Briefly explain how binary fission occurs
- DNA replicates
- Cell elongates
- DNA copies move to opposite sides of the cell
- Ingrowth of membrane occurs
- Cytoplasm divides to form two daughter cells
- Bacteria produce themselves every 20 minutes
- leads to create clones (identical daughter cells)
Important consequences of bacterial reproduction
- Wounds become heavily infected very quickly
- Appear in large numbers
- Can transfer plasmids and antibiotic resistance
- Efficient returns of product in industry
Define Endospore
- unicellular resistant structure produced during harsh conditions
Steps in endospore formation
- DNA replicates
- Cytoplasm shrinks
- DNA is surrounded by a thick cell wall
- Outer cell breaks down
- Endospores remain dominant for decades
When conditions are suitable again
- Endospore absorbs water
- Spore wall softens and ruptures
- A new bacterial cell emerges, enlarges and reproduces by binary fission
What is meant by autotrophic?
Make their own food
Define Photosynthetic and give an example
Use light to make food
eg: Purple sulphur bacteria
Define Chemosynthetic
Use energy from chemical reactions
eg: Nitrifying bacteria