List of practice Questions

Homing pigeons can perceive the pattern of polarized light in the sky (which depends on the position of the sun relative to the earth). This enables homing pigeons to orient and navigate home if released in any location. One can reset their biological clock in captivity by artificially controlling the light conditions. If you acclimatize a pigeon to a new lighting cycle with "sunrise" at 6 PM and "sunset" at 6 AM, instead of 6 AM sunrise and 6 PM sunset that naturally occurs, the bird will be clock-shifted by 12 hours within a few days. Suppose you release two birds, a normal bird (N) and a 12-hr clock-adjusted bird (C), 30 km East of their home at 6 AM. In which direction will each bird fly?
Demographic stochasticity introduces random variation in population growth because
According to the MacArthur – Wilson equilibrium model of island biogeography, which one (or more) of the following factors affect(s) extinction rate on an island?
Rising temperature due to global warming can stimulate decomposition of organic matter and release CO\(_2\) into the atmosphere. This is an example of
Ant-mimic spiders of the genus Myrmarachne are known for which one of the following evolutionary phenomena?
Grazing by large mammalian herbivores can have a strong influence on ecosystem structure, and can cause ecosystems to transition between alternative states over decades. Which one of the following transitions can result from grazing?
The effective population size of a sexually reproducing, diploid, animal species will be highest when the sex ratio (number of reproducing males / number of reproducing females) is
The theory of evolution by natural selection was proposed by which one (or more) of the following?
Which one of the following mammalian DNA regions exhibits the highest level of sequence variation?
Which one of the following makes a species most vulnerable to extinction?
Two sister species of bulbuls have non-overlapping distributions. One is distributed in India and the other in Sri Lanka. Which of the following modes of speciation is the most parsimonious explanation for this pattern?
In an Arctic Ocean food chain, killer whales feed on sea otters, which feed on sea urchins, which in turn feed on kelp (a type of seaweed). An increase in the abundance of killer whales causes sea otter abundance to decline, leading to higher sea urchin densities, which in turn reduces the abundance of kelp. Which of the following terms describes this phenomenon?
Listed below are hypotheses for the evolution of monogamy. Which one of these is NOT based on the concept of individual selection?
Of the following, which one is the most direct measure of Darwinian fitness?
The marginal value theorem in optimal foraging theory examines which one of the following foraging decisions?
Which one of the following shows the highest degree of endemism?
Which one of the following Mendelian disorders is influenced by diet?
Animal species can vary in whether dispersal is more likely among male offspring (male-biased), female offspring (female-biased), or similar between the sexes. Dispersal in birds and mammals is most commonly:

In the circuit given below, \(V_s = 50\ \text{V}\). Let the circuit reach steady state for the SPDT switch at position 1. Once the circuit is switched to position 2, the energy dissipated in the resistors is \(\underline{\hspace{1cm}}\) J (rounded off to one decimal place). 

In the circuit shown below, the output voltage \(V_{out}\) is \(\underline{\hspace{1cm}}\) V. 

In the circuit shown below, \( R_1 = 2 \, \Omega \), \( R_2 = 1 \, \Omega \), \( L_1 = 2 \, H \), and \( L_2 = 0.5 \, H \). Which of the following describe(s) the characteristics of the circuit? 

A novel biomaterial was tested for its tensile properties. The experiment was conducted using a cylindrical sample of this material, which was 10 cm long with 1 cm diameter. When a tensile force of 50 kN was applied, this cylindrical sample elongated by 4 mm. Based on the experimental results described above and the tensile moduli of different tissues given in the table below, this biomaterial would be a suitable replacement for \(\underline{\hspace{2cm}}\). 
\[\begin{array}{|c|c|} \hline \textbf{Tissue} & \textbf{Tensile modulus} \\ \hline \text{Bone} & \text{5 – 20 GPa} \\ \hline \text{Tendon} & \text{0.5 – 1 GPa} \\ \hline \text{Ligament} & \text{20 – 400 MPa} \\ \hline \text{Articular cartilage} & \text{3 – 10 MPa} \\ \hline \end{array}\]

Match the following organs with their functions: 

Match the following in the context of biomaterial characterization: 

As shown in the circuit below, a constant voltage source is connected to two ideal resistors. 
The voltage drop across a resistor is measured using two different voltmeters V1 and V2 at five different time instances and the following values are recorded from V1 and V2.