Question

Gene therapy consist of

	A.	replacing the genomes of an individual with a brand new set of genomes with the goal of treating a genetic defect.
	B.	replacing a defective gene in an individual with a normal gene with the goal of treating a genetic disorder.
	C.	transferring a modified gene into an individual with the goal of treating a genetic defect.
	D.	transferring a normal or a modified gene into an individual with the goal of treating a genetic defect.
	E.	replacing a defective enzyme in an individual with a normal enzyme with the goal of treating a genetic disorder.

DNA transcription is

	A.	The use of a mRNA template to synthesis DNA
	B.	The use of a DNA template to synthesis mRNA
	C.	The use of a mRNA template to synthesis Proteins.
	D.	The use of a tRNA template to synthesis DNA
	E.	The use of a Protein template to synthesis mRNA

DNA sequencing is a method

	A.	of determining the order of fatty acids in a DNA.
	B.	of determining the order of saccharides in a DNA.
	C.	of determining the order of amino acids in a DNA.
	D.	of determining the order of nucleotides in a DNA.
	E.	of determining the order of triglycerides in a DNA.

Answer 1

Answer::

(1)D

(2)B

(3)D

Explanation::

(1) Gene therapy is a technique for correcting defective genes which are responsible for disease development which means the main aim of gene therapy is typically aim to supplement a defective mutant allele with functional one.

A normal gene may be inserted into nonspecific location within the genome it is termed as gene addition,or abnormal gene can be replaced by normal gene through homologous recombination called gene replacement and lastly an abnormal gene can be repaired through selective reverse mutation ,which returns the gene to its normal function.Here the most common approach is the gene addition where gene transfer into nonspecific location to cure defective gene.

Gene therapy are of two types germ line and somatic gene therapy.Somatic gene therapy relates with introduction of gene into somatic cells(bone marrow,blood,skin) of an affected individual whereas in germline gene therapy involves the permanent transmissible modification of genome of a gamete,zygote or early embryo.

So if only one answer correct then you will go with option D which is most approchable gene therapy called gene addition..and for more than one answer it will be B&D..

(2) Transcription is a process of formation of mRNA from DNA template.It takes place through the usual complementary base pairing,catalyzed and scrutinized by enzyme RNA polymerase.It normally occurs unidirectionally in which RNA chain is synthesized in 5'-3' direction.Only one DNA strands act as a template on which RNA strand is built.It is different from replication as it doesnot need primer,it only copies certain parts of genome called transcriptional unit but in replication entire genome replicates with the help of primer.

From RNA to DNA synthesis is called reverse transcription and from RNA to protein synthesis called translation.

(3)As we know DNA are composed of deoxyribose sugar , nitrogenous base and phosphate called nucleotides ..so sequencing will gives the order of nucleotides bases such as Adenine(A) ,Guanine(G), Cytosine(C) and Thymine(T).It is a biochemical methods for determining the order of nucleotides base. The method may be chain termination,chemical degradation and pyrosequencing method ..all gives order of A,T,G,C .