Recent questions without answers

Which of the following statements about immune response are $CORRECT$?$T$ cells are activated by antigen-presenting cellsForeign peptides are not presented to helper $T$ ...

Which of the following statemets are $CORRECT$ about eukaryotic cell cycle?$CDKs$ can phosphorylate proteins in the absence of cyclins$CDKs$ can be inactivated by phospho...

$W,X$ and $Y$ are the intermediates in a biochemical pathway as shown below:$$S \cdots \cdots \rightarrow W\rightarrow X\rightarrow Y\rightarrow Z$$Mutants auxotrophic fo...

In tomato plant, red ($R$) is dominant over yellow ($r$) for fruit color and purple ($P$) is dominant over green ($p$) for stem color. Fruit color and stem color assort i...

Some of the cytokinins used in plant tissue culture media are given below:$BAP$ZeatinKinetin$2iP$Which of these are synthetic analogs?$P$ and $Q$ only$Q$ and $S$ only$R$ ...

Carl Woese used the gene sequence of which one of the following for phylogenetic taxonomy of prokaryotes?A ribosomal $RNA$ of large ribosomal subunitA ribosomal $RNA$ of...

A list of pathogens $(Group\; I)$ and a list of anti-microbial agents $(Group\; II)$ used to treat their infections are given below. Match the pathogens with the correspo...

Determine the correctness or otherwise of the following Assertion [$a$] and the Reason [$r$].Assertion [$a$]: Dam methylase protects $E$. coli $DNA$ from phage endonuclea...

Determine the correctness or otherwise of the following Assertion [$a$] and the Reason [$r$].Assertion [$a$]: Embryonic stem cells are suitable for developing knockout mi...

The schematic of a plasmid with a gap in one of the strands is shown below:Which of the following enzyme(s) is/are required to fill the gap and generate a covalently clos...

Match sub-cellular organelles listed in $Group\; I$ with their features listed in $Group\; II$:$$\begin{array}{|cl|cI|cI|cI|cI|c|}\hline&\textbf{Group I} & \textbf{Group ...

Which of the following strategies are used by cells for metabolic regulation?Phosphorylation-dephosphorylationAllosteryFeedback inhibition$P$ and $Q$ only$P$ and $R$ only...

Determine the correctness or otherwise of the following Assertion [$a$] and the Reason [$r$].Assertion [$a$]: A zygote and its immediate descendant cells are unspecialize...

Which of the following statements about gene therapy are CORRECT?Affected individuals, but not their progeny, can be cured through germline gene therapyAffected individua...

Determine the correctness or otherwise of the following Assertion [$a$] and the Reason [$r$].Assertion [$a$]: A genetically engineered rice that produces beta-carotene in...

The sequence of a $1$ $Mb$ long $DNA$ is random. This $DNA$ has all four bases occurring in equal proportion. The number of nucleotides, on average, between two successiv...

$E$ coli was grown in $^{15}N$ medium for several generations. Cells were then transferred to $^{14}N$ medium, allowed to grow for $4$ generations and $DNA$ was isolated ...

A batch reactor is inoculated with $1 \:g/L$ biomass. Under these conditions, cells exhibit a lag phase of $30$ min. If the specific growth rate in the log phase is $0.00...

The system of linear equations$$cx+y=5$$$$3x+3y=6$$has no solution when $c$ is equal to _______________________.

The amino acid sequence of a peptide is $Phe-Leu-lle-Met-Ser-Leu$. The number of codons that encode the amino acids present in this peptide is given below:Phe: $2$ codons...

Assume that a cell culture was started with five human fibroblast cells. Two cells did not divide even once whereas the other three cells completed three rounds of cell d...

Growth of an organism on glucose in a chemostat is characterized by Monod model with specific growth rate = $0.45 \:h^{-1}$ and $K_{s}= 0.5 \:g/L$. Biomass from the subst...

A function $f$ is given as :$$f(X)=4X-X^{2}$$The function $f$ is maximized when $X$ is equal to _________________.

An infinite series $S$ is given as:$S=1+2/3+3/9+4/27+5/81+\:.\dots$ (to infinity)The value of $S$ is ______________________ (round off to $2$ decimal places).

Protein $A$ and protein $B$ form a covalent complex. Gel filtration chromatography of this complex showed a peak corresponding to $200 \:kDa$. $SDS-PAGE$ analysis of this...

The concentrations of $ATP$, $ADP$ and inorganic phosphate in a cell are $2.59, \:0.73$ and $2.72 \:mM$, respectively. Under these conditions, free energy change for the ...

An algorithm was designed to find globins in protein sequence databases. A database which has $78$ globin sequences was searched using this algorithm. The algorithm retri...

The mitochondrial electron transfer chain oxidizes $NADH$ with oxygen being the terminal electron acceptor. The redox potentials for the two half-reactions are given belo...

Rajiv Gandhi Khel Ratna Award was conferred _______ Mary Kom, a six-time world champion in boxing, recently in a ceremony _______ the Rashtrapati Bhawan (the President’s ...

Despite a string of poor performances, the chances of K.L. Rahul’s selection in the team are ________slimbrightobviousuncertain

Select the word that fits the analogy:$\text{Cover : Uncover :: Associate :}$ _______UnassociateInassociateMisassociateDissociate

Hit by floods, the kharif (summer sown) crops in various parts of the country have been affected. Officials believe that the loss in production of the kharif crops can be...

The difference between the sum of the first $2n$ natural numbers and the sum of the first $n$ odd natural numbers is ______$n^2-n$$n^2+n$$2n^2-n$$2n^2+n$

Repo rate is the rate at which Reserve Bank of India $\text{(RBI)}$ lends commercial banks, and reverse repo rate is the rate at which $\text{(RBI)}$ borrows money from c...

$P,Q,R,S,T,U,V,$ and $W$ are seated around a circular table.$S$ is seated opposite to $W$$U$ is seated at the second place to the right of $R$$T$ is seated at the third p...

The distance between Delhi and Agra is $233$ km. A car $P$ started travelling from Delhi to Agra and another car $Q$ started from Agra to Delhi along the same road $1$ ho...

For a matrix $M=[m_{ij}]; \: i,j=1,2,3,4$, the diagonal elements are all zero and $m_{ij}=-m_{ji}$. The minimum number of elements required to fully specify the matrix is...

Protein $P$ becomes functional upon phosphorylation of a serine residue. Replacing this serine with _____________ will result in a phosphomimic mutant of $P$.alanineaspar...

Ras protein is atrimeric GTPase involved in relaying signal from cell surface to nucleusmonomeric GTPase involved in relaying signal from cell surface to nucleustrimeric ...

Which of the following statements are $CORRECT$? Viruses can play a role in causing human cancer.A tumor suppressor gene can be turned off without any change in its $DNA$...