List of top Life Science Questions on Life Science asked in GATE XL

The synthesis of thyroxine T4 in the human body requires

Match the standard/stated cofactors in Column I with their respective enzymes in Column II 

Match the immunological statements in Column I with the appropriate descriptions from Column II. 

Match the syndromes listed in Column I with the cause/symptoms listed in Column II. 

Match the hormones/precursors listed in Column I with their chemical type in Column II and the tissue of origin listed in Column III.

During the exponential growth, it took 6 hours for the population of bacterial cells to increase from \(2.5 \times 10^6\) to \(5 \times 10^{8}\). The generation time of the bacterium, rounded off to the nearest integer, is _______ minutes.
Match the cell types in Group I with the processes in Group II.
Group I
(p) NK cells
(q) B cells
(r) Mast cells
(s) Neutrophils
Group II
(i) Antibody production
(ii) First cells to be recruited at the site of infection
(iii) Antibody-dependent cell-mediated cytotoxicity
(iv) Histamine production

Enzyme activity profiles as a function of time in the absence or presence of different types of feedback mechanisms are shown in the figure below. Match the following feedback mechanisms with the corresponding profiles in the figure. 
(p) No feedback mechanism 
(q) Negative feedback mechanism with short delay 
(r) Negative feedback mechanism with long delay 
(s) Positive feedback mechanism 

Intracellular concentrations of ATP, ADP, and inorganic phosphate in four cell types are given below. Which one of these cell types has the most negative \(\Delta G\) for ATP hydrolysis? 

Cell typeATP (mM)ADP (mM)Inorganic phosphate (mM)
L3.01.85.0
K3.91.33.0
B2.70.72.7
M7.20.98.0

Match the coordination complexes given in Column I with the most appropriate properties in Column II. (Given: Atomic numbers of Mn: 25; Co: 27; Ni: 28) 

A mixture of four peptides, PKKRK, RGERV, RYRGV and LVVYP, is loaded onto an ion-exchange column at pH = 7.2. If carboxymethyl (CM) cellulose is used as the stationary phase of this column, then which peptide elutes first? 

Suitable reagent(s) to bring about the conversion of P to Q in good yield is/are 

What is the major product formed in the given reaction? 

An opaque cylinder (shown below) is suspended in the path of a parallel beam of light, such that its shadow is cast on a screen oriented perpendicular to the direction of the light beam. The cylinder can be reoriented in any direction within the light beam. Under these conditions, which one of the shadows P, Q, R, and S is NOT possible?

Which one of the given figures P, Q, R, and S represents the graph of the following function? \[ f(x) = |x + 2| - |x - 1| \]

\(E^\circ = 1.10\ \text{V}\) for the cell: \(\mathrm{Zn(s) + Cu^{2+}(aq) \rightleftharpoons Zn^{2+}(aq) + Cu(s)}\). At \(298\ \text{K}\), the equilibrium constant is \(y \times 10^{37}\). Find \(y\) (to two decimals). (Given: \(F = 96485\ \text{C mol}^{-1}\), \(R = 8.314\ \text{J K}^{-1}\text{mol}^{-1}\)).
Which among the following is NOT an essential amino acid?
Wild-type Drosophila females having three linked genes (AABBCC) were crossed with triple recessive mutant (aabbcc) males. The F1 females (AaBbCc) were backcrossed with aabbcc males. The following F2 progeny numbers were obtained (total = 1000). The gene order is ABC. Find the recombination map distance (in cM) between A and C (round to one decimal place). \begin{tabular}{l r} AaBbCc & 241
Aabbcc & 112
aaBbCc & 103
aabbcc & 252
aaBbcc & 17
aabbCc & 134
AabbCc & 14
AaBbcc & 127
\end{tabular}
Choose the correct group of fat soluble vitamins.
In an experiment, excess amount of bicoid mRNA (more than wild-type expression level) was injected into the posterior pole of a wild-type Drosophila embryo at pre-blastodermal stage. Out of the following options, which one represents the best expected phenotype in the resulted developing embryo?
Which of the following techniques is/are used for determining the three-dimensional structure of proteins?
Which one of the following represents a true “Ecological population”?
Which of the following animals show “Bottle cells” during the gastrulation stage of development?
Which of the following is/are the causative agent(s) of Filariasis?
In a population of 1000 wild dogs in a grassland, 360 and 480 dogs had black body colour with genotypes BB and Bb, respectively. In the same population, remaining dogs were white in colour with a genotype of bb. Based on this data, the frequency of allele “b” in the population is _______ (round off to one decimal place).