Question

 

QUESTION 21

In human cells, the activity of ____________ is required to set the transition from G1 to S phase in motion.

		only a cyclin
		only a cyclin-dependent kinase (CDK)
		a CDK complexed to a cyclin
		an RNA-induced silencing complex
		the telomerase enzyme

QUESTION 22

Transgenic crop plants engineered by recombiant DNA technology can express genes derived from

		Another crop variety of the same species
		Another plant species of the same genus
		Another eukaryotic organism
		Another cellular organism, but not viruses
		Any oprganism, including viruses

QUESTION 23

Which of the following occurs in both meiosis and mitosis?

		Pairing and synapsis of homologous chromosomes.
		Formation of synaptonemal complex between homologous pairs of chromosomes.
		Non-sister chromatids exchange large fragments of DNA between one-another.
		Chromosomes condense, nuclear membrane dissolves.
		Both sister chromatids of a chromosome are pulled to the same pole of the cell in anaphase.

  

QUESTION 24

What is the name of the protein structure on the eukaryotic chromosome that makes physical contact with the spindle fibers during metaphase of mitosis?

		Origin of transfer
		Kinetochores
		Origins of replications
		Telomere
		Separase

QUESTION 25

_______________bacterial strains are able to grow in minimal medium which provides only inorganic nutrients and a carbon source.

		Obligate biotrophic
		Prototrophic
		Necrotrophic
		Heterotrophic
		Auxotrophic

QUESTION 26

Retroviruses can cause cancer by

		Bringing the cell cycle to an abrupt stop.
		Triggering the expression of tumor suppressor genes.
		Erroneously activating the transcription of the host cellâ s proto-oncogenes from a strong viral promoter.
		induction of programmed cell death
		by injecting base analogues into host cells

QUESTION 27

Which procedure requires the removal of a single cell from a morula-stage human embryo?

		Pre-implantation genetic diagnosis
		Reproductive cloning
		Therapeutic cloning
		Cloning a PCR fragment in plasmid vector
		The genetic tansformation of a plant

QUESTION 28

The construction of a cDNA library involves the following steps: (A) purification of mRNA from cells; (B) insertion of the double-stranded cDNA into a vector; (C) synthesis of the second cDNA strand; (D) annealing of oligo(dT) primers to polyA tails and reverse transcription of the first cDNA strand. The correct order in which these steps are performed is:

		A, B, C, D.
		A, D, B, C.
		D, C, A, B.
		B, A, C, D.
		A, D, C, B

QUESTION 29

The cultivated coffee (Coffea arabica) is a fertile allotetraploid species with a 2n chromosome number of 44. How many chromosomes are in the gametes of Coffea arabica?

		Cannot be determined, because an allotetraploid species produces unbalanced gametes with varying number of chromosomes.
		11
		22
		33
		44

Answer 1

QUESTION 21

Every phase of cell cycle needs a specific set of CDK and a cyclin. Not only for the regulation of the cellcycle but also for the progression of the cell cycle from one phase to another phase(except some of the lower eukaryotes, like S. pombe). For G1 to S phase transition CDK 2 and Cyc E in needed.

QUESTION 22

Genetic engeneering can help in formation of transgenic plant by recombinant technology using any DNA sequence derived from eukaryotes, prokaryotes and viruses. Mainly viral genes are recombinanat with plants to achieve antiviral resistant.

QUESTION 23

The basic difference between Meiosis and mitosis is that, in mitosis there NO PAIRING OF HOMOLOGOUS CHROMOSOME. While in acse of meiosis the homologous chromosome show pairing. For this pairing first in prophase 1 one could see sequentially---pairing, fromation of synoptonimal complex, synapsis, crossing over which is marked by exchange of DNA fragments. Again the condensation and dissolvation of chromosome can be seen in both the mitosis and meiosis for segregation and separation of chromosome.

QUESTION 24

Kinetochore situated in the centromere of the chromosome. It is a protein complex that help in binding of the tubuline proteins of the spindle fiber.the proteins of the Kinetochore also help in sensing the strength of the microtubule attached to the chromosome during chromosomal migration.

Whereas, the Origine of replication is a sequence where the replication process starts when bound with DNA polymerase.

Telomerase: is a repetative sequence of chromosome present at the end of the chromosome.

Separase: is an enzyme that hydrolysis the cohesin protein, that hold the sister chromatids together.

QUESTION 28

The sequence of the c-DNA library is that,

First the mRNA is purified from the cell. Then the mRNA is reverse transcripted to Single stranded c-DNA by reverse transcriptase. After that SS c-DNA is made. Two SS c DNA is annealed and transfer to a vector.

QUESTION 29

Allotetraploidy is 4 times the chromosome number than gamete.