​Savannas are biomes where tree and grass vegetation coexist over large areas. Which one of the following statements does NOT explain the occurrence of savannas in the Indian subcontinent?​

Given below are the different stages of Arabidopsis embryogenesis (Column X) and their characteristic patterns of cell division (Column Y).
Column X
A. Zygotic
B. Globular
C. Heart
D. Torpedo
Column Y
i. Formation of an 8-cell embryo, exhibiting radial symmetry and undergoing additional cell division to create the protoderm
ii. Polarized growth of cells followed by a symmetric transverse division giving rise to a small apical cell and an elongated basal cell
iii. Cell elongation and cellular differentiation processes throughout the embryonic axis with visible distinction between the adaxial and abaxial tissue of the cotyledons
iv. Focused cell division forming two cotyledons, giving bilateral symmetry to the embryo
Which one of the following options represents the correct match between Column X and Column Y?

The taxon cycle is the predicted, progressive ecological and evolutionary changes in the descendants of founding populations. Taking the case of insular biotas, the figure can be used to conceptualize and predict species types (a, b, c, d, e, f, g, h) based on their fundamental capacities to evolve, immigrate, and persist.

The table below has species types (Column X) and the possible traits (Column Y) associated with each type.

Which one of the following options represents all correct matches between Column X and Column Y?

The figure shows a life-cycle graph and the corresponding population projection matrix (time-invariant) for a population with four successive classes (1–4). All contributions to class 1 from other classes occur via fecundity. There is no resource limitation.

Initial population sizes are:
n₁ = 95, n₂ = 5, n₃ = 15, n₄ = 4.
The following statements are made regarding the future population states in a long-term simulation of population growth:
A. The population will grow and attain a stable class distribution.
B. The population will grow but the number of individuals in each class will be proportional to the initial numbers.
C. The population will grow but numbers of individuals in the classes will fluctuate disproportionately over time.
D. The population will grow at a fixed growth rate and all classes will grow at the same rate.
Which one of the following options represents a combination of all correct outcomes?

The table below lists taxonomic groups (Column X) and their morphological features (Column Y).
Column X
A. Crustacea
B. Chelicerata
C. Phoronida
Column Y
i. Two pairs of antennae
ii. Antennae absent
iii. Presence of lophophore
Which one of the following options represents all correct matches between Column X and Column Y?

The following statements describe some features of a Quartz Crystal Microbalance (QCM) biosensor:
A. A QCM biosensor is built with a thin disc-shaped piezoelectric material connected to metal electrodes on opposite faces.
B. When an AC voltage is applied to the quartz crystal, it produces oscillation at a stable resonant frequency that is not determined by the applied AC voltage.
C. The surface of the quartz crystal can be functionalized with a specific receptor that binds to the target analyte.
D. As the mass on the surface of the crystal increases, the resonant frequency of the crystal increases in a predictable, quantitative way following the Sauerbrey equation.
Which one of the following options represents a combination of all correct statements?

In a polluted aquatic environment, bacteria are chronically exposed to low concentrations of multiple antibiotics released from pharmaceutical effluents. Over time, resistant colonies appear even when the antibiotic concentration remains constant. To determine whether resistance arises through induced mutation (a physiological response to antibiotics) or random mutation followed by selection, an ecologist performs a fluctuation test similar to that of Luria and Delbrück (1943) using replicate bacterial cultures.
Which one of the following outcomes would best support the conclusion that antibiotic resistance arises by random mutation followed by selection, rather than by induction?

Conjugation experiments were performed by mixing four different auxotrophic strains (P, Q, R, and S) of E. coli in different combinations. The generation of prototrophs on appropriate minimal selective media is shown below:
Combination of strains No. of prototrophs obtained
P and Q - 20
S and R  -1000
P and R - 0
P and S  - 1000
Based on the above data, the following statements were made:
A. Strains P and R are F⁻ strains.
B. Strain Q is an F⁺ strain.
C. Strain S is an Hfr strain.
D. Strains P and R are F⁺ and F⁻ strains, respectively.
E. Strains P and R are both Hfr strains.
Which one of the following options represents a combination of all correct statements?

The following statements are made regarding colchicine treatment in plants for inducing polyploidy.
A. In colchicine-treated cells, sister chromatids cannot separate during anaphase, leading to chromosome doubling when the nucleus reforms.
B. Colchicine stimulates endoreduplication in the treated cells, bypassing cytokinesis to yield polyploid cells in a process called “C-mitosis”.
C. In sterile interspecific hybrids, colchicine treatment may restore fertility by converting them into amphipolyploids.
D. Colchicine treatment during meiosis has no effect, as it only acts on mitotic cells.
E. Colchicine binds to tubulin and prevents spindle fibre formation during mitosis.
Which one of the following options represents a combination of all correct statements?

In amphibians and fish, the cells of the organizer ultimately contribute to i) pharyngeal endoderm, ii) head mesoderm, iii) dorsal mesoderm, and iv) dorsal blastopore lip. The following statements are made about the function of the organizer and its derivatives:
A. The pharyngeal endoderm and pre-chordal plate prevent formation of forebrain and midbrain.
B. The organizer has the ability to dorsalize the ectoderm and induce formation of the neural tube.
C. The dorsal mesoderm inhibits induction of the hindbrain and trunk.
D. The organizer tissue possesses the ability to dorsalize the surrounding mesoderm into somite-forming mesoderm.
Which one of the following options is a combination of all correct statements?

A B6 mouse (H-2b haplotype) was crossed with a CBA mouse (H-2k haplotype) to generate F1 progeny. The following skin transplant experiments were then performed:
A. Graft from B6 mouse to CBA mouse
B. Graft from F1 mouse to B6 parent
C. Graft from F1 mouse to CBA parent
D. Graft from F1 mouse to F1 mouse
E. Graft from B6 mouse to F1 mouse
Which one of the following options represents all recipients in which the graft is tolerated?