Biology

Molecular Biology and Genetics

985 Questions

Molecular biology and genetics explore the structure and function of DNA, RNA, genetic mutations, and heredity. Understanding these building blocks of life is essential for most biology examinations. Review these practice questions to test your molecular genetics knowledge.

DNA structure and basesGenetic mutationsNucleic acids compositionDNA sequencing and replication

Molecular Biology and Genetics Questions

Multiple choice

Identify the mismatched pairs among the following: A. Chaperones: infectious proteinaceous particles. B. Domains: Independently folded functional unit of a proteinC. C Prion: Proteins that assist in proper folding of proteins. D. Zinc finger: Small, functional, independently folded domain that coordinates one or more zinc ions to stabilize its structure.

  1. A and B only

  2. B and C only

  3. A and C only

  4. B and D only

  5. A, C and D only
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Chaperones are a functionally related group of proteins assisting proper protein folding in the cell under physiological and stress conditions. Prions are proteins that are unique in their ability to reproduce on their own and become infectious.

Multiple choice

What is the main objective of using Northern hybridization?

Northern hybridization involves the use of electrophoresis to separate RNA samples by size and detection with a hybridization probe complementary to part of or the entire target sequence. The term 'northern blot' actually refers specifically to the capillary transfer of RNA from the electrophoresis gel to the blotting membrane.

  1. To separate DNA

  2. To separate RNA

  3. To identify protein

  4. For DNA sequencing

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This technique is useful in the identification and separation of the RNA that is complementary to a specific DNA probe.

Multiple choice

In Western blotting, which of the following is used as probe for the identification of glycoproteins?

A hybridization probe is a fragment of DNA or RNA of variable length (usually 100-1000 bases long), which is used in DNA or RNA samples to detect the presence of nucleotide sequences (the DNA target) that are complementary to the sequence in the probe.

  1. Antibodies

  2. Molecular Beacon probes

  3. Cycling probe technology

  4. Lectins

  5. Locked Nucleic Acid probes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A glycoprotein detected by lectin blotting with concanavalin A was also identified using this technique.

Multiple choice

A mixture of four proteins of pls 11, 7, 5 and 3 are loaded on DEAE anion-exchange column equilibrated with low ionic strength buffer of pH 8. Which of the four proteins would be expected to be retained on the column?

  1. Protein with pI 11 but not the others

  2. Proteins with pl 11 and 7 but not 5 and 3

  3. Proteins with pl 7, 5 and 3

  4. Protein with pl 7 but not the others
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

DEAE is a positively charged anion-exchange column, meaning it binds negatively charged proteins. At pH 8, proteins with a pI lower than the buffer pH of 8 will carry a net negative charge and thus be retained on the column. The proteins with pI 7, 5, and 3 all have pIs less than 8, so they are negatively charged at pH 8 and will be retained, whereas the protein with pI 11 will be positively charged and flow through.

Multiple choice

The DNA content of a nucleus can be measured by

  1. ESR Spectroscopy

  2. FTIR Spectroscopy

  3. Flow Cytometry

  4. X-Ray Crystallography
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Flow cytometry utilizes fluorescent stains, such as propidium iodide, to bind stoichiometrically to DNA, allowing the rapid measurement of the cellular DNA content across a large population of nuclei or cells. Other techniques listed are used for structure determination or chemical bonding analysis.

Multiple choice

RNA is considered as the first genetic material to have evolved on the earth. Which one of the following properties of RNA is critical for its functioning as the genetic material in the absence of DNA and protein?

  1. The presence of uracil as a base in place of thymine

  2. The RNA is less stable than DNA; therefore RNA has higher probability to evolve as genetic material as compared to DNA

  3. The single stranded RNA has a genotype as well as phenotype

  4. RNA exists in 3 forms while DNA has only one form
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ribozymes and single-stranded RNA molecules can fold into complex three-dimensional structures that possess catalytic activity (phenotype) while simultaneously storing sequence information (genotype).

Multiple choice plant kingdom biology

Choose the correct statement.

  1. Haploid contained of human DNA is4.6$\times{10}^6$bp

  2. A nitrogenous base is linked to pentose sugar through phosphodiester linkage

  3. X-ray diffraction data of Maurice Wilkins and Rosalind Franklin was the basis of Watson and Crick's DNA model

  4. DNA is an acidic substance was first identified by Watson and Crick
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Watson and Crick relied heavily on experimental data, including the X-ray diffraction images produced by Rosalind Franklin and Maurice Wilkins, to deduce the double helix structure of DNA. The other statements contain factual inaccuracies regarding base pairing links, genome size, or historical attribution.

Multiple choice biology meaning of life chemical organization in living beings lipids proteins and their structure

In which one of the following combinations, the compounds are arranged in ascending order based on their molecular weights?

  1. DNA, RNA, AMP, ADP, ATP

  2. DNA, RNA, ATP, ADP, AMP

  3. AMP, ADP, ATP, RNA, DNA

  4. AMP, ATP, ADP, DNA, RNA
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Molecular weights increase from AMP (monophosphate) to ADP (diphosphate) to ATP (triphosphate). RNA and DNA are polymers of nucleotides and thus have significantly higher molecular weights than individual nucleotides.

Multiple choice botany biotechnology: principles and processes downstream processing biotechnology biotechnology and its application

Purines possess nitrogen at

  1. 1, 2, 4 and 6 positions

  2. 1, 3, 5 and 7 positions

  3. 1, 3, 7 and 9 positions

  4. 1, 2, 6 and 8 positions
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Purines are heterocyclic aromatic organic compounds. In the purine ring structure (a fused pyrimidine and imidazole ring), the nitrogen atoms are located at positions 1, 3, 7, and 9.