Questions
Which of the following structures are found in prokaryotic cells?
I. A cell wall with peptidoglycan.
II. A plasma membrane without cholesterol.
II. Ribosomes.
- I only
- II only
- III only
- I and II only
- I, II and III
Bacteriophages are the obligate parasites of bacterial cells. They transfers bacterial DNA from one host to another. What is this phenomenon called?
- Transformation
- Transduction
- Conjugation
- Transcription
- Translation
Which of the following statements is true of a lysogenic cell?
- A cell that harbors an inactive virus in its genome.
- A cell that has developed immunity from viral infection.
- A cell that undergoes self destruction.
- Any cell infected with a virus.
- A cell that is about to lyse as a result of viral infection.
Which of the following feature provide easy recognition of a bacteriophage?
- A lysogenic life cycle
- A protein capsid
- Circular nucleic acids
- A tail and fibers
- A fatty capsule
Which of the following characters is related to saprophytic nature of fungi?
- Reproduction by budding
- Reproduction by sporulation
- Locomotion by creeping
- Respiration through membrane
- Nutrition on decayed matter
A structures that can never be found in the capsid of a virion is ___________.
- single stranded RNA
- linear double stranded RNA
- circular double stranded RNA
- ribosomes
- reverse transcriptase
Why are fungi placed in a distinct kingdom?
- Because they do not undergo mitosis.
- Because they reproduce asexually.
- Because their sexual reproduction involves the union of different mating types strains.
- Because they have characteristics that are both plant-like and animal-like.
- Because they are non green and can not produce their own food.
A phage sensitive strain of E. coli is grown in the environment containig DNA from phage resistant bacteria. After incubation, the sensitive strain becomes resistant. Which of the following mechanisms is responsible for this event?
- Transduction
- Transformation
- Conjugation
- Replication
- Translation
When E.coli is placed in a sterile nutrient rich media it undergoes exponential growth. Which of the following phenomenon is responsible for this?
- Transduction
- Sporulation
- Transformation
- Binary fission
- Conjugation
What must happen to bacteriophage prior to infecting a bacterium?
- It should reproduce to make multiple copies of the phage chromosome.
- It should integrate its genome into the bacterial chromosome.
- It should penetrate the bacterial cell wall completely.
- It should attach to a receptor on the bacterial cell membrane.
- It should undergo shrinkage in its size.
Which of the following features is associated with the lipopolysaccharide layer outside the peptidoglycan cell wall of a gram negative bacterium?
- It absorbs and holds gram stain.
- It protects the bacterium against certain antibiotics.
- It does not contain phospholipids.
- It allows the bacterium to attach to solid objects.
- It assists in the process of cell division.
What is the advantage offered by the haploid state to the fungal life cycle?
- Quick reproduction
- More genetically diverse
- Large number of cell production
- Energy conservation for life sustenance
- Spread of the infective stage to healthy host
Staphylococcus is a Gram-positive bacteria, which includes several species that can cause a wide variety of infections in humans and other animals through infection or the production of toxins. Staphylococcal toxins are a common cause of food poisoning. What is the shape of the causative agent?
- Rod-shaped
- Spherical
- Spiral
- Comma shaped
- Square
Which of the following features is correctly described about the most viruses that infect animals?
- Enter the host cell via endocytosis.
- Do not require a receptor protein to recognize the host cell.
- Leave their capsid outside the host cell.
- Can reproduce independently of a host cell.
- Leave only their protein outside the host cell.
To which character of feeding are virus associated?
- Facultative anaerobes
- Aerobes
- Saprophytes
- Parasites
- Chemotrophs