List of top Life Science Questions asked in GATE XL

The DNA double helix is stabilized primarily by:
Which pyramid is always upright in an ecosystem?
Which phase of the cell cycle is known as the resting phase?
Which of the following amino acids is essential in human diet?
The process of conversion of nitrogen into ammonia by bacteria is called:
Which of the following is a stop codon?
Imagine a population of diploid species in Hardy-Weinberg equilibrium. The population has two alleles for a gene which are ‘a’ and ‘A’. The number of individuals with ‘aa’ genotype in this population is 1 in 10000. The frequency of the allele ‘A’ in the population is ............ (up to two decimal places)
The \( F_{121} \) value of a known microorganism with \( Z \) value of \( 11^\circ C \) is 2.4 min for 99.9999% inactivation. For a 12D inactivation of the said microorganism at \( 143^\circ C \), the \( F \) value (in min) is .......... {(rounded off to 3 decimal places)}
In a typical grinding operation, 80% of the feed material passes through a sieve opening of 4.75 mm; whereas, 80% of the ground product passes through 0.5 mm opening. If the power required to grind 2 tonnes/h of the feed material is 3.8 kW, the work index of the material is ........ (rounded off to 2 decimal places)
The true density and bulk density of wheat grains are 1280 kg/m\(^3\) and 740 kg/m\(^3\), respectively. The porosity of the grains is ......... (rounded off to 2 decimal places).
The true density and bulk density of wheat grains are 1280 kg/m\(^3\) and 740 kg/m\(^3\), respectively. The porosity of the grains is ......... (rounded off to 2 decimal places).
The mother and the father of five children are carriers (heterozygous) of an autosomal recessive allele that causes cystic fibrosis. The probability of having exactly three normal children among five is ........ (up to two decimal places).
A PCR was setup to amplify a 500 nucleotides-long DNA. The dNTPs in the reaction mixture were radiolabeled. The percentage (%) of radiolabeled single-stranded DNA after three cycles will be ............ (up to one decimal place)
In a typical grinding operation, 80% of the feed material passes through a sieve opening of 4.75 mm; whereas, 80% of the ground product passes through 0.5 mm opening. If the power required to grind 2 tonnes/h of the feed material is 3.8 kW, the work index of the material is ........ (rounded off to 2 decimal places)
The \( F_{121} \) value of a known microorganism with \( Z \) value of \( 11^\circ C \) is 2.4 min for 99.9999% inactivation. For a 12D inactivation of the said microorganism at \( 143^\circ C \), the \( F \) value (in min) is .......... {(rounded off to 3 decimal places)}
An enzyme, which follows Michaelis-Menten equation, catalyzes the reaction A\(\rightarrow\)B. When enzyme and substrate concentrations are 15 nM and 10 \(\mu\)M, respectively, the reaction velocity is 5 \(\mu\)M s\(^{-1}\). If \(K_m\) for the substrate A is 5 \(\mu\)M, the kinetic efficiency of the enzyme will be ______ \(\times 10^6\) M\(^{-1}\) s\(^{-1}\) (in integer).
If an egg cell of a diploid plant species has 10 chromosomes, the expected number of chromosomes in a double trisomic somatic cell of this species would be ............. (Answer in integer).
The equilibrium dissociation constant of acetic acid is \( 1.74 \times 10^{-5} \) M. The \( pK_a \) of acetic acid (rounded off to one decimal place) is ......

The \( F_{121} \) value of a known microorganism with \( Z \) value of \( 11^\circ C \) is 2.4 min for 99.9999% inactivation. For a 12D inactivation of the said microorganism at \( 143^\circ C \), the \( F \) value (in min) is .......... (rounded off to 3 decimal places)

Match the following enzymes in Column I with their applications in Column II.

Identify the CORRECT sequence of operations for dressing of poultry.
Which of the following contains the phytonutrient allicin?
Which of the following animals in India are included under "critically endangered" threat category as per the Red Data List of IUCN?
The expression of a gene is regulated by a transcription factor. Which of the following techniques can be used to identify the region in its promoter where the transcription factor binds?

Match the molecules in Column-I with their correct property/function in Column-II