Biology

DNA and Genetics

985 Questions

DNA and genetics questions explore molecular biology, DNA replication, and genetic engineering techniques. These topics are essential for various competitive exams requiring a strong foundation in life sciences. Practice these questions to understand complex biological processes thoroughly.

DNA replication mechanismsGenetic engineering techniquesGene editing toolsPolymerase chain reactionDNA sequencing methods

DNA and Genetics Questions

Multiple choice biology micro organisms non cellular organism : virus world of virus bacteria - introduction, shape and structure

The latest view for the origin of virus is that

  1. They arose from nucleic acid and protein found in primitive water.

  2. They arose from bacteria as a result of loss of cell wall.

  3. They arose from some of the bacteria, which had developed a nucleus only.

  4. They are modified plasmids, which are fragments of the nucleic acids of the host.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Viruses play an important role in horizontal gene transfer and genetic diversity. The evolution history showcases the origin of viruses as to have evolved from plasmids when pieces of DNA moved between cells. As
big bits of cellular DNA became independent and some DNA stuck with cell genomes. Thus, the correct answer is option D.

Multiple choice zoology evolution of life darwin's theory of evolution process of evolution lamarckism

Find out the incorrect match from the following.

  1. Natural selection- Charles Darwin

  2. Mutation theory- Carl Correns

  3. Use and disuse theory- Lamarck

  4. Chemical evolution- Oparin and Haldane
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Natural selection was given by Charles Darwin. It states that the organism which are able to evolve according to changing environment are able to survive for longer duration and are naturally selected to evolve.
Mutation theory states that evolution is a sudden process where new varieties and species are formed by mutation which is considered as sudden change in the genome due to induced and natural factors. It was given by Hugo de Vries.
Use and disuse theory was given by Lamarck, which states that animals acquired characteristics after using certain physical traits constantly.
Chemical evolution states that life originated through certain simple organic molecules. It was proved by Oparin and Haldane.
Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Binding of specific proteins on regulatory DNA sequences can be studied by means of 

  1. Electron microscope

  2. Light microscope

  3. Centrifugation

  4. X-ray crystallography
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

X-ray crystallography is a technique to study the structural details of crystallizable proteins and nucleic acids. X-ray microscope developed by Kirkpatrick is useful in studying detailed structures of chemicals present in solid state, e.g., haemoglobin, insulin, DNA, RNA etc. due to diffraction of X rays by different atoms of the substance. 

Binding of specific proteins on regulatory sequences of DNA will generate specific diffraction pattern of X rays which can help to identify specific proteins binding to specific regulatory regions in DNA.

Multiple choice botany cell and cellular organization cell theory microscope cell and its discovery

Binding of specific proteins on regulatory DNA sequences can be studied by means of

  1. Electron microscope

  2. Light microscope

  3. Centrifugation

  4. X-ray crystallography
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The detailed structural views of protein-DNA interfaces have been obtained through X-ray crystallography and NMR spectroscopy.

Multiple choice

DNA controls characteristics of an organism. True or False?

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

DNA contains the genetic instructions that determine an organism's physical traits, behaviors, and biological functions. These instructions are passed down from parents to offspring during reproduction.

Multiple choice

Which is an example of a vector?

  1. Bacteria

  2. Plasmid

  3. Cell

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In genetic engineering, a vector is a DNA molecule used to transport foreign genetic material into another cell. Plasmids, which are small circular DNA molecules found in bacteria, are the most commonly used vectors.

Multiple choice

which enzyme has the function to join segments of DNA together?

  1. Gyrase

  2. Helicase

  3. None of the above

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

DNA ligase is the enzyme responsible for joining DNA strands together by catalyzing the formation of a phosphodiester bond, which is crucial for sealing nicks in the sugar-phosphate backbone during replication and repair.

Multiple choice

During the polymerase chain reaction, heat is used to

  1. break covalent bonds

  2. break hydrogen bonds

  3. accelerate chemical processes

  4. anneal DNA primers
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the denaturation step of PCR, high temperatures are used to break the relatively weak hydrogen bonds holding the two complementary DNA strands together, separating them without damaging the stronger covalent bonds of the backbone.

Multiple choice

Where are telomeres located?

  1. At the end of the chromosome

  2. On the leading strand

  3. At the replication fork

  4. on prokaryotic plasmids
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Telomeres are repetitive nucleotide sequences found at the very ends of linear eukaryotic chromosomes, serving to protect the chromosome ends from degradation and fusion.