Tag: zoology

Quizzes (289) Questions (5869)

Questions Related to zoology

Multiple choice zoology molecular basis of inheritance the search for genetic material dna structure and replication molecular genetics

In Griffiths experiment, the conversion of R- type to S-type of Diplococcus pneumoniae when mixed with heat-killed S-type is called

  1. Mutation

  2. Transduction

  3. Transfection

  4. Transformation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Transformation is the process by which bacteria take up naked DNA from their environment, as demonstrated by Griffith's experiment with S and R strains of Streptococcus pneumoniae.

Multiple choice zoology molecular basis of inheritance the search for genetic material dna structure and replication molecular genetics

Which of the following is true with reference to transformation in bacteria
i) Transfer of genetic material is mediated by F factor
ii) Uptake of DNA fragments from the surrounding environment and expression of that genetic information in recipient cell 
iii) Transformation experiments were the basis to propose chromosomal theory of inheritance
iv) Transformation was discovered by Griffith in Streptococcus pneumonia

  1. i, iv

  2. ii, iii, iv

  3. iii, iv

  4. ii, iv
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement ii is correct (definition of transformation) and iv is correct (Griffith's discovery). Statement i refers to conjugation, and iii is historically incorrect as transformation was not the basis for the chromosomal theory of inheritance.

Multiple choice zoology molecular basis of inheritance the search for genetic material dna structure and replication molecular genetics

A molecule that acts as a genetic material must fulfill the traits given, except

  1. It should provide the scope for slow changes that are required for evolution

  2. It should be able to generate its replica

  3. It should be able to express itself in the form of Mendelian characters

  4. It should be unstable structurally and chemically
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Genetic material must be stable to store information accurately over generations. If it were unstable, it could not reliably pass on traits.

Multiple choice zoology molecular basis of inheritance the search for genetic material dna structure and replication molecular genetics

Escherichia coli in which both the strands are labelled with $^{15}N$ is transferred to $^{14}N$ medium and allowed to replicate for two generations. Find the number of hybrid DNA molecules in the second generation

  1. Four

  2. Eight

  3. One

  4. Two
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In semi-conservative replication, after one generation, all DNA is hybrid. After two generations, half the DNA is hybrid and half is light (14N-14N). Starting with one 15N-15N molecule, after two generations, you have four molecules: two hybrid (15N-14N) and two light (14N-14N).

Multiple choice zoology molecular basis of inheritance the search for genetic material dna structure and replication molecular genetics

Beside direct chemical analysis DNA and RNA can be detected by which of the following method?
a. Photometric procedures
b. Staining reactions
c. Enzyme digestion
Select the correct answer using the codes given.

  1. $1, 2$ and $3$
  2. $1$ and $2$
  3. $2$ and $3$
  4. $1$ and $3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

DNA and RNA can be detected using photometric procedures (like UV absorbance), staining reactions (like Feulgen stain for DNA), and enzyme digestion (using DNase or RNase to confirm identity).

Multiple choice zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

Activated sludge should have the ability to settle quickly so that it can:

  1. be rapidly pumped back from sedimentation tank to aeration tank

  2. absorb pathogenic bacteria present in wastewater while sinking to the bottom of the settling tank

  3. be discarded and anaerobically digested

  4. absorb colloidal organic matter.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The activated sludge have to settle quickly so that it can be pumped back to the aeration tank. So, the correct option is 'be rapidly pumped back from sedimentation tank to aeration tank'

Multiple choice zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

In the sewage treatment, bacterial flocs are allowed to sediment in a settling tank. This sediment is called as:

  1. inactivated sludge

  2. activated sludge

  3. primary sludge

  4. secondary sluge
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
In the secondary treatment, the effluent is passed into a settling tank where the bacterial flocs are allowed to sediment and the sediment is called activated sludge.
So, the correct option is 'activated sludge'
Multiple choice zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

The primary treatment of removal of:

  1. dissolved impurities

  2. stable particles

  3. toxic substances

  4. harmful bacteria
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The primary treatment involves physical removal of particles from the sewage through filtration and sedimentation. These are removed initially by sequential filtration which removes the floating debris and then grit is removed by sedimentation. 

So, the correct option is 'Option A' .

Multiple choice zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

Wastewater treatment generates a large quantity of sludge, which can be treated by:

  1. anaerobic digesters

  2. floc

  3. chemicals

  4. oxidation pond
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Wastewater treatment generates a large quantity of activated sludge during secondary treatment which is used as a inoculum and a small part of it is pumped back to the large aeration tanks whereas the remaining part of that sludge is treated by anaerobic sludge digesters anaerobically. During this digestion, bacteria produces a mixture of gases called biogas. 

So, the correct option is 'Option A' .

Multiple choice zoology introduction to microbiology microbial pollution control environmental use of microorganism microbes in waste treatment and biogas

Activated sludge should have the ability to settle quickly so that it can

  1. Be rapidly pumped back from sedimentation tank aeration tank.

  2. Absorb pathogenic Bactria present in waste water while sinking to the bottom of the settling tank

  3. Be discarded and anaerobic ally digested

  4. Absorb colloidal organic matter
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Activated sludge should have the ability to settle quickly so that it can be rapidly pumped back from sedimentation tank to the aeration tank, where it can start the process of decomposition of the organic matter again. Activated sludge has filamentous bacteria that are capable of performing the aerobic digestion of organic waste is the sewage water.

Hence, the correct answer is 'Be rapidly pumped back from sedimentation tank aeration tank'