List of top Questions asked in GATE Ecology and Evolution

There are nine species of Impatiens (balsams) found in laterite plateaus of the northern Western Ghats, each with a distinct colour. If a plateau has exactly 6 species, then the number of possible colour combinations in the plateau is ….. (Answer in integer).

The figure illustrates the soil zinc tolerance of the grass species Anthoxanthum along a transect from inside a mine to the middle of a pasture outside the mine.
\includegraphics[width=0.5\linewidth]{62a.png} 
Which one or more of the following processes explain(s) the observed pattern of zinc tolerance in this grass species?

Consider a discrete random variable \( X \) that takes values from the set \( S = \{0, 1, 2, 3\} \), being the number of individuals of a species within a habitat. Consider the probability distribution of \( X \) with \( Pr(X = 0) = 0.15 \), \( Pr(X = 1) = 0.25 \), and \( Pr(X = 3) = 0.5 \), where \( Pr \) denotes probability. The value of \( Pr(X = 2) \) is \_\_\_\_\_\_\_\_. (Round off to two decimal places).
In a forest, there are tigers, hare, and deer. On a given day, the probability of a tiger hunting a hare is 0.35, a deer is 0.25, and either a hare or a deer is 0.55. The probability of a tiger hunting both a hare and a deer on a given day is \_\_\_\_\_\_\_\_, (Round off to two decimal places).
One hypothesis for why the tropics have far greater species richness than higher latitudes is that the tropics are relatively aseasonal. Low seasonality can encourage high species richness through which one or more of the following mechanisms?
A phylogenetic tree for the evolution of two pigmentation traits in species of fish is shown for clades X, Y, and Z. Genes A and/or B, if mutated, can cause dark pigmentation in the body.
\includegraphics[width=0.5\linewidth]{57a.png}
Which one or more of the following statements is/are correct?
You are a plant ecologist studying a plant in the genus \textit{Veronica. You notice that, at open rocky sites, \textit{Veronica} grows as a creeper spreading low to the ground, whereas in grasslands, the stem stands upright. You collect seeds from multiple populations in each habitat type and grow them under uniform conditions in a greenhouse. You find that all the plants grown in the greenhouse have stems that stand upright. Which one or more of the following explanations best support(s) your observations?}
Males of the Indian robin in two populations sing songs of different lengths. Which one or more of the options given is/are an ultimate (not proximate) explanation(s) of the difference in song length between the two populations?
In the foodweb diagrams shown, R represents the primary producer, C1 and C2 represent intermediate consumers, and P represents the top predator. Which one or more of these diagrams show(s) intraguild predation? \includegraphics[width=0.5\linewidth]{59a.png}
In conservation biology, which one or more of the following is/are used to calculate the effective population size, \( N_e \)?
Which one or more of the following is/are greenhouse gas(es)?
Female \textit{Anopheles mosquitoes bite humans to get blood. Researchers performed an experiment to study whether female mosquitoes use temperature or scent, or both, when locating human hosts. They presented female mosquitoes with membranes kept at different temperatures. Some membranes had human scent applied to them. The response to each treatment was measured as the percentage of females that landed on the membrane (50 females for each treatment). The table shows the treatments and the corresponding responses.}
Grey langurs found in the southern Western Ghats (SWG) and grey langurs in Sri Lanka (SL) look very similar. Nilgiri langurs (found in SWG) and purple faced langurs (found in SL) also look similar. If allopatry played a role in the early diversification of this group (at point X in the tree), which one of the phylogenetic trees is most likely to be correct?
\includegraphics[width=0.5\linewidth]{52a.png}
Match the mollusc taxa to their respective orders as shown in the table.
\includegraphics[width=0.5\linewidth]{50a.png}
A terrestrial species P is found in both India and West Africa and nowhere else, while a marine species Q is found in the Arabian Sea and the Bay of Bengal. The two species have similar generation times. An ecologist builds haplotype networks based on DNA sequences from these species, where each circle represents one haplotype and each dash (--) represents a mutation. Which one of the following inferences is best supported by the haplotype networks shown?
\includegraphics[width=0.5\linewidth]{51a.png}
Two bird species, \(A\) and \(B\), are found on a single mountainside. \(A\) is a low-elevation species, found between 500 m and 1500 m Above Sea Level (ASL), while \(B\) is a high-elevation species, found between 1000 m and 2000 m ASL. At 1250 m ASL, species \(A\) and \(B\) have very different bill morphologies, but the bill morphology of species \(A\) at 500 m is very similar to the bill morphology of species \(B\) at 2000 m ASL. Which one or more of the following explain(s) the difference in bill morphology at 1250 m ASL?
The graphs shown represent the relationship between population size (\(N\)) and population growth rate \(\frac{dN}{dt}\). Which one of the following growth curves represents a density-dependent population that experiences a strong Allee effect?
\includegraphics[width=0.5\linewidth]{44.png}
Honey bees are haplodiploid, which means that the relatedness is, on average, expected to be 0.75 between:
There are two species, X and Y, with abundances \(x\) and \(y\), respectively. Species X has growth rate \(\alpha\), and species Y has growth rate \(\beta\). Assume that the sum of the species abundances is constant over time, i.e., \(x + y = 1\). Let \(x\) and \(y\) follow the rate equations: \[ \frac{dx}{dt} = \alpha x - \varphi x, \quad \frac{dy}{dt} = \beta y - \varphi y, \] where \(\varphi\) is the average species fitness. Which one of the following options correctly represents the expression for \(\varphi\)?
The abundance (X) of a plant species with respect to the anthropogenic stressor habitat destruction (h) is shown. The solid and the dashed curves represent stable and unstable population equilibrium abundances, respectively. \includegraphics[width=0.5\linewidth]{45a.png}
In the absence of any stochasticity, and with increasing values of h, what is the value of h at which a sudden population collapse would occur?
Consider the graph shown, where \(S\) is species richness and \(A\) is area. \(S\) and \(A\) are log-transformed and the slope is not equal to 1.
\includegraphics[width=0.5\linewidth]{46.png}
The relationship between untransformed \(S\) and \(A\) follows a/an:
The graph shows the rank-abundance relationships for species in three communities, \(P\), \(Q\), and \(R\). \includegraphics[width=0.5\linewidth]{47.png}
Which one of the following statements is true with respect to the evenness of the three communities?
The graph shows bird species richness in a large contiguous forest patch and a small adjacent forest fragment, before and soon after the large contiguous forest patch was replaced by an oil palm plantation.
\includegraphics[width=0.5\linewidth]{48.png}
Which one of the following options best explains the pattern shown?
Given below is a table with ecological observations and processes. \begin{center} \begin{tabular}{|l|l|} \hline Ecological observations & Processes
\hline P) Bright spotted pigmentation in guppy males in low predation habitats & I) Kin selection
Q) Vampire bats share blood meals & II) Sexual selection
R) Cooperative breeding in African weaver birds & III) Reciprocal altruism
\hline \end{tabular} \end{center} Select the option that best matches each ecological observation with its corresponding process.
Males of the swordtail fish \textit{Xiphophorus helleri possess long tails, while those of \textit{X. maculatus} do not. Females of \textit{X. helleri} prefer males with longer tails. Interestingly, experimental studies show that females of \textit{X. maculatus} prefer \textit{X. maculatus} males with attached artificial long tails over those without.} If the long-tailed \textit{Xiphophorus species evolved from ancestors that lacked a long tail, which one of the following processes best explains the evolution of the observed preference among \textit{X. maculatus} females?}