Which statement about bacterial structure is INCORRECT?
Bacteria have cell walls.
Bacteria have a nucleus.
Bacteria can have flagella for motility.
Bacteria have ribosomes.
Select the INCORRECT statement about peptidoglycan.
Peptidoglycan is the target of antibiotics.
Only bacterial cell walls contain peptidoglycan.
All bacterial cells have an equal amount of peptidoglycan in their cell wall.
Which of the following is statements about the bacterial cell wall is NOT correct?
It is a rigid macromolecular layer which provides strength to the cell.
It confers cell shape and protects cell from lysing via osmosis.
It has pores to allow transport of macromolecules.
Gram-positive bacteria have a simple, thick complex, thin( simple, thick, complex, thin ) layer of peptidoglycan as their cell wall, which retains the crystal violet safranin (pink)( crystal violet, safranin (pink) ) Gram stain even when washed with alcohol. Gram-negative bacteria have a complex simple( complex, simple ) cell wall with a thin thick( thin, thick ) layer of peptidoglycan, therefore the gram stain can be washed out with alcohol and the safranin gram stain( safranin, gram stain ) dyes the cells pink orange( pink, orange ).
Choose the INCORRECT statement about bacterial flagella.
Flagella act as a propeller.
Flagella have 3 structures: the long filament, the flexible 'hook', and the rigid basal body.
The 'running' motion of bacteria is due to the clockwise rotation of the flagella.
Flagella give bacteria motility and allow them to move at high speeds, and change direction.
Which statements about bacterial movement are true?
Bacteria rotate the flagellum CCW to 'run' and CW to stop and rotate/turn.
Random movement promotes a higher chance of finding nutrients.
Bacteria only exhibit positive chemotaxis.
Bacteria are too small to sense a spatial gradient, and must detect gradients by moving over time (temporal gradient).
Which of the following statements about bacterial fimbriae/pili are CORRECT?
They allow bacteria to adhere to surfaces.
They play a role in bacterial motility.
Fimbriae/pili have proteins called adhesins which bind to specific receptors on cell surfaces.
All bacteria have fimbriae/pili.
Which statement about bacterial capsid layers are INCORRECT?
All capsid layers are made of glycocalyx, which forms a sticky mesh of fibres.
If the layer is disorganised and loosely attached to the cell wall, it is called a slime layer.
If the layer is organised and firmly attached to the cell wall, it is called a capsule.
Capsules can provide nutrients, protection from antibodies, and prevent cell desiccation.
Gram-negative bacteria do not have capsules.
Which of these statements about endospores are CORRECT?
Endospores are very heat resistant, but not very chemical resistant.
Only some gram-positive bacteria can produce endospores.
The trigger for making endospores is a certain stage of the bacteria's life cycle.
Endospores can last up to 50 million years in their dormant state.
Which of these is NOT a type of endospore?
Terminal
Sub-terminal
Central
Sub-central
Which of these is NOT a specific property of endospores?
Low water content
High Ca2+ concentration
Many layers not present in the typical vegetative cell
Low metabolic activity
No diplicolinic acid
Prokaryotic cells are ❌. They have ❌ endomembrane system ❌ cytoskeleton, their DNA is ❌, and they reproduce via ❌. Eukaryotic cells are larger and often multicellular. They have ❌ endomembrane system (e.g. nucleus, ER, Golgi, etc) and a cytoskeleton. Their DNA is ❌ and they reproduce via meiosis and mitosis.
