Top Bio Interview Questions
What Are Immunoglobulins? Explain Its Structure
Immunoglobulins are popularly known as antibody. These are large Y-shaped protein produced by B-cells that is used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. Immunoglobulins are “Y” shaped structure which is having two tips and each tip of immunoglobulins contains a paratope.
Immunoglobulins are typically made of basic structural units—each with two large heavy chains and two small light chains. The general structure of all antibodies is very similar; a small region at the tip of the protein is extremely variable.
What Is The Principle Behind Dna Fingerprinting?
DNA fingerprinting is the technique of genetic fingerprinting. In this technique, DNA sequence can be used for identification of an individual. The main application of DNA fingerprinting is forensics. The main principle behind behind DNA fingerprinting is Polymerase Chain Reaction. This technique is also popularly known as DNA profiling.
Differentiate Between Gram Positive And Gram Negative Bacteria?
In gram staining protocol, gram positive bacteria are stained dark blue or violet. Crystal violet stain can be retained by the gram positive bacteria because of the high amount of the peptidoglycan in the cell wall. Gram-positive cell walls typically lack the outer membrane found in Gram-negative bacteria.
In gram staining protocol, gram negative bacteria do not retain crystal violet dye. Gram negative bacteria have pathogenic capability. Gram negative bacteria have cytoplasmic membrane which is not present in gram positive bacteria.
Explain Forbidden Clones?
Clones refer to producing genetically identical individuals. Forbidden clones refer to clones of those cells which has immunological reactivity with self antigens. Embryonic life is eliminated from these types of clones. Such type of clones is called ‘forbidden clones’.
Explain Microarrays. How Are They Related To Dna?
Microarrays are matrix in the form of arrays where DNA oligonucleotides of DNA sequences are spotted. They can be used for gene expression profiling, single nucleotide polymorphism detection, detection of alternative splicing and for various other purposes. Microarrays have the capability to perform hybridization of coda with the help of probes. A microarray chip is capable to perform a large set of genetic related experiments concurrently.
What Is Bmi?
BMI stands for body mass index. This index represents the comparison of the person’s height and weight. The weight of the person is divided by the square of the person’s height. The SI unit for measuring BMI in kg/sq.m. BMI should not be treated as a technique for measuring body fat.
Explain Gram Staining Method?
This method is used to identify bacterial species into two communities i.e. Gram positive and gram negative. This method is based on chemical and physical properties of their cell walls. It can be used to detect peptidoglycan, which is present in a thick layer in Gram positive bacteria.
Purple/blue colour refers to the gram positive bacteria. Red colour stain refers to the gram negative bacteria. This method is very popularly used in the identification of bacterial organism.
Explain Is Isotopic Tracer Technique?
This technique is used to understand chemical reaction and interactions in bio-chemistry and chemistry. In this technique, one or more of the atoms of the molecule of interest is substituted for an atom of the same chemical element, but that element belongs to different isotope.
It can be used to detect the difference in number of neutrons separately from the other atoms of the same element. The atom has the same number of protons; it will behave in almost exactly the same way chemically as other atoms in the compound, and with few exceptions will not interfere with the reaction under investigation.
What Is Frame Shift Mutation? Is This Mutation Similar To Single-nucleotide Polymorphism?
This is the type of mutation in which DNA sequence is changed due to addition and deletion of nucleotides. This mutation changes the code for amino acids. This is also called framing error or reading frame shift. This mutation will cause the reading of the codons after the mutation to code for different amino acids.
No, this mutation is not similar to single-nucleotide polymorphism. In single-nucleotide polymorphism nucleotide is replaced, rather than inserted or deleted.
What Is Therapeutic Cloning?
In the process of cloning DNA or a part of DNA is duplicated. This process is also called somatic cell nuclear transfer. In this process embryo is utilized for cloning. Embryo comprises of stem cells which is later employed in regeneration applications. The embryonic stem cells are renewable and are pluripotent.
Explain Superiority Of Tlc Over Paper Chromatography?
TLC is superior over paper chromatography because of inorganic nature of adsorbent concentrated sulfuric acid spray. The spray is then followed by heating. It may be used to develop on the chromatogram by charring. Also, amino acid mixtures require 18 hours for separation on paper.
It requires 3 hrs using cellulose TLC. The advantages of TLC lie in adsorbents which don’t allow separation on paper. In TLC we have much wider choice of adsorbents depending upon needs and sample.
What Is Alzheimer’s Disease?
Alzheimer disease is the most common form of dementia. It is a brain disease caused due to tau protein misfolding. This disease is incurable. This is degenerative disease. It can be diagnosed through MRI scan or PET. This disease is found in generally above 65 years of age.
Its symptoms include irritation, confusion, mood swings and aggression. This disease is named after German psychiatrist and neuropathologist Alois Alzheimer in 1906.