Ecological Principles MCQ Quiz in मल्याळम - Objective Question with Answer for Ecological Principles - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

The correct answer is "Offspring do not require elaborate parental care"

Explanation-

Monogamy in birds often evolves when there is a need for parental care, and both parents contribute to raising offspring. If offspring do not require elaborate parental care, there may be less pressure for both parents to stay together.

Option 1- "Poor quality of habitat wherein resources are hard to find":

• Monogamy is advantageous in this scenario because maintaining a territory with necessary resources for breeding and offspring-raising can be challenging. Two parents can better secure and defend resources against intruders.

Option 2 -"Males guard females after mating with them":

• In this case, monogamy is beneficial because it ensures that a male's effort is devoted to his own offspring. By guarding the female, the male prevents other males from mating with her, thereby ensuring paternal certainty.

Option 3-"Mates are scattered and hard to find":

• In species where finding mates takes considerable time and energy, monogamy can be beneficial because it reduces the energy spent on seeking out numerous partners.

Additional Information Monogamy and polygamy are two types of mating systems commonly found among animals. These systems tend to evolve based on what is most conducive for reproductive success in a given environment.

1. Monogamy:

• Monogamy, when an individual mates with only one partner over a defined period, is relatively rare in the animal kingdom but is more common in birds. This can either be serial (having a new partner every breeding season) or lifelong (staying with the same partner for life).
• Example of monogamy in animals is penguins. Emperor penguins, for instance, form monogamous pairs for each breeding season. Both partners share the incubation duties and care for their single offspring.
• Gibbons (primates), swans, albatrosses, and bald eagles also often form lifelong monogamous relationships.

2. Polygamy:- Polygamy, when an individual mates with multiple partners, is the most common mating system among animals. This can take on a few different forms:-

• Polygyny is when one male mates with multiple females. This is the most common form of polygamy. Many deer species like red deer are polygynous, with males (stags) establishing small harems of females (hinds) during the breeding season.
• Polyandry is when one female mates with multiple males. This is much rarer. An example is the jacana, a tropical bird species. In this case, females are larger and more brightly colored than males. The female mates with multiple males, and the males incubate the eggs and raise the chicks.
• Polygynandry is when multiple males mate with multiple females. One example is the bonobo, a species of primate, in which both males and females have multiple sexual partners, and sexual interactions play a key role in the social dynamics of the group.

Monogamy can increase survival for offspring that need care from both parents, but it may limit the number of offspring one could potentially have. Polygamy can increase the number of offspring but can also increase competition and aggression, especially among males.

The correct answer is Option 1 i.e.Industrial production of fertilizers 

Explanation-

The activity that contributes the most nitrogen to the global nitrogen cycle is the industrial production of fertilizers.

• Industrial production of fertilizers - Agriculture has greatly altered the nitrogen cycle, primarily through the use of synthetic nitrogen fertilizers. These fertilizers, which are produced through the Haber-Bosch process, significantly increase the amount of biologically available nitrogen in the environment.Burning fossil fuels, application of nitrogen-based fertilizers, and other activities can dramatically increase the amount of biologically available nitrogen in an ecosystem. 
• NOx production due to combustion of fossil fuels - While this process does contribute to the nitrogen cycle, its contribution is less compared to the amount of nitrogen released by the industrial production of fertilizers.
• Nitrogen fixation by soybean farming - Soybeans, like other legumes, can convert atmospheric nitrogen into a biologically useful form through a process known as nitrogen fixation. However, the area globally used for soybean farming is significantly less compared to the area exposed to synthetic nitrogen fertilizers.
• Nitrogen fixation by the cultivation of legumes (excluding soybean) - Similar to soybean farming, other legume crops also contribute to the global nitrogen cycle through nitrogen fixation. Even though a variety of legume crops are grown worldwide, the accumulated contribution of these crops is less compared to the industrial production of fertilizers.

Concept:

• Ecologists use k-selection and r-selection to describe the reproductive strategies of the population.
• r-selection has a high growth rate with a low survival rate. 
• k-selection has a low growth rate with a high survival rate. 

1. r-selection/strategies:
   • It is seen in the region with unstable environmental conditions where due to unstable environment, there is a high degree of fluctuation in population density.
   • The conditions select r-strategies, where organisms have rapid development, a small body size, early reproduction, and breed once in a lifetime (semelparity) and short life span.
   • Species here compensate for high offspring loss by producing many unprotected youngs from which few survive to repeat the life cycle. 
   • Hence, this species spent more energy on reproduction.
   • For example, bacteria, algae, and annual plants adopt r-strategies.
   • These species are opportunistic and can disperse rapidly when conditions are favourable. Hence, many are pioneer species. 
2. k-selection/strategies:
   • It is seen in the region with predictable and almost constant environmental conditions. 
   • Due to favourable conditions, species reach carrying capacity and hence, have a high average population density.
   • They produce few offspring, attain large body sizes, delay reproduction, breed multiple times (iteroparity), and have a long life span.
   • These species spent less energy in reproduction but more energy in nurturing and protecting their young ones. 

Explanation:

• Insects and cephalopods show r-selection where they produce a large number of offspring, breed once in a lifetime, and have short life spans. So, they have high growth rate and low survival rate. 
• Proboscids are animals having an elongated appendage on their head. In the case of vertebrates, it is an extension of the nose called the snout. This is present in some organisms like elephants, tapirs, proboscis monkeys, etc. 
• Cetacean is the name given to a group of mammals that includes whales, dolphins and porpoises.
• Proboscids and cetaceans are large organisms that show k-selection because they produce fewer offspring, have a large body size and breed multiple times in their lifetime. 
• Hence, the correct answer is option 1.

The correct answer is Option 4 i.e.grasses → herbs and shrubs → woody trees

Concept:

• Succession is a process of directional changes that is universal in an ecological community over some time in an ecological time scale. 
• This change is unidirectional series of changes that leads to an establishment of a relatively stable community at the end of the succession.
• Each stage in the succession is called the seral stage.
• Each seral stage is marked by its own species composition, which makes the place more habitable for the next stage.
• Eventually, the community reaches a steady equilibrium where the succession slows down and the final community is called the climax community of that habitat.
• Succession includes both structural as well as functional changes in the community.
• Types of succession:

1. Primary succession: If succession occurs on a barren piece of land or a new volcanic island where a community never existed then this type of succession is called primary succession.
2. Secondary succession: If succession occurs in a land where the community was already developed but was destroyed due to some natural disturbance, then it is called secondary succession.

Important Points

Steps of Succession - 

Explanation:

• Succession on the piece of land that was originally destroyed by fires is an example of secondary succession.
• Such a land may lack vegetation, but may still contain seeds or other propagules of plants.
• Thus, there is no need for Nudation or Migration to take place during the initiation phase of succession.
• Plant species may re-establish themselves from the seeds or propagules already available.
• Grasses are found to be highly resilient and thus, easily grow under these circumstances.
• Many grass family seeds have been found to remain viable after forest fires, facilitating the re-establishment process.
• Thus, grasses are the first plants found during re-establishment of the community.
• These are followed by herbs and shrubs, which finally leads to woody trees forming a climax forest community.

​ Hence, the correct answer is Option 4.

Confusion Points

• Please note that lichens and mosses are the pioneer species only for primary xerarch succession.
• They help to colonize the barren land as they utilize the inorganic components present in the area to carry out metabolism.
• After they die, they leave behind organic matter that acts as the substrate for other organisms.
• Mosses and lichens also help in soil formation and adding humus to the soil.

Explanation

Carrying capacity is the upper limit of a species to grow. The logistic equation assumes that the intrinsic rate of natural increase is progressively reduced as population size increases toward the carrying capacity. The logistic equation is \(\rm\frac{dN}{dt} = rN\left(\frac{K-N}{K}\right)\)

When, N is more than K the \(\rm\frac{dN}{dt}\) value will be negative but when equal, the density change becomes zero.

The correct answer is polygynandry 

Explanation:

• Monogamy (1): This refers to a mating system where one male pairs with one female for a breeding season or longer. This is not applicable here as the pairs have multiple mating partners.
• Polyandry (2): This describes a mating system in which one female has multiple male partners. While this involves multiple partners, it specifically refers to the female's mating strategy, not the male-female pair's overall mating behavior.
• Polygyny (3): This refers to a system where one male has multiple female partners. Again, this does not describe the scenario where male-female pairs have multiple partners.
• Polygynandry (4): This term refers to a mating system where both males and females have multiple mating partners within a group or breeding season. In the case of salamanders, if male-female pairs engage with multiple partners, this is accurately termed polygynandry. Polygynandry can enhance genetic diversity and reproductive success in certain species. It allows for more mating opportunities and can result in varied genetic combinations among offspring.

The correct answer is Option 1

Explanation:

A (C1 and C4 similarity): C1 and C4 both contain Sp1, Sp5, and Sp6 with differing quantities, showing a moderate level of similarity.
B (C3 diversity): C3 is dominated by Sp4 (100), with minor contributions from other species (Sp3 and Sp6). This suggests it is the least diverse due to the overwhelming dominance of Sp4.
C (C1 and C4 diversity): These communities have a more balanced spread across several species compared to C2 and C3. C2 is dominated by Sp2, and C3 is overwhelmingly populated by Sp4, indicating less diversity.
D (C2 and C3 similarity): C2 and C3 do not show strong similarity. C2 has a high abundance of Sp2, while C3 is dominated by Sp4 with no overlap in dominance

Conclusion:

Therefore, the correct statements are A,B and C

The correct answer is Option 3

Explanation:

The distribution patterns of these species based on the given data (mean and variance of their occurrences in quadrats), we can  Poisson distribution, which is often used to model the distribution of rare events in a fixed area of opportunity (like the occurrence of plant species in quadrats).

For a Poisson distribution:

• If the variance is approximately equal to the mean, the distribution is considered random.
• If the variance is significantly higher than the mean, the distribution is considered to be clustered.
• If the variance is significantly lower than the mean, the distribution is considered to be uniformly distributed (though this case does not apply directly to the given options).

Applying this to the provided data:

Species 1: Mean = 16.2, Variance = 48.

• The variance (48) is significantly higher than the mean (16.2), suggesting that species 1 is distributed in a clustered manner.

Species 2: Mean = 3.6, Variance = 3.2.

• The variance (3.2) is roughly equal to the mean (3.6), indicating a random distribution.

Conclusion:

Based on these considerations Option c i.e.Species 1 is clustered and species 2 is distributed randomly.

The correct answer is Option 2 i.e. Species B wins

Explanation:

The Lotka-Volterra model of interspecific competition can be summarized by the following equations for two species A and B:

• \(( \frac{dN_A}{dt} = r_A N_A \left(1 - \frac{N_A + \alpha N_B}{K_A}\right) )\)
• \(( \frac{dN_B}{dt} = r_B N_B \left(1 - \frac{N_B + \beta N_A}{K_B}\right) )\)

Where,

• N_A and N_B are the population sizes of species A and B, respectively.
• r_A and r_B are the intrinsic rates of increase of species A and B, respectively.
• K_A and K_B are the carrying capacities of species A and B, respectively.

\(\alpha\) and \(\beta\) are the competition coefficients, which indicate how strongly individuals of one species affect individuals of the other species. Specifically, \(\alpha\) measures the effect of species B on species A, and  \(\beta\)measures the effect of species A on species B.
Given:

• K_A = 150, K_B = 200
• \(\alpha\)= 1.0
•  \(\beta\)= 1.3

The conditions that predict the outcome of competition between two species can be determined by comparing the ratios of carrying capacities to competition coefficients.

• Species A will outcompete species B if: (\( \frac{K_A}{\alpha} > K_B \)) and (\( \frac{K_B}{\beta} < K_A \))
• Species B will outcompete species A if: ( \(\frac{K_A}{\alpha} < K_B\) ) and ( \(\frac{K_B}{\beta} > K_A\) )
• Both species reach a stable equilibrium if: ( \(\frac{K_A}{\alpha} > K_B\) ) and ( \(\frac{K_B}{\beta} > K_A \))
• An unstable equilibrium would imply boundary conditions not directly predicted by simple inequalities above.

For the given values, let's evaluate the conditions:

 \(\frac{K_A}{\alpha} = \frac{150}{1.0} = 150 \)
 \(\frac{K_B}{\beta} = \frac{200}{1.3} \approx 153.85\) 
Now comparing to the conditions:

• Since ( \(\frac{K_A}{\alpha} = 150 \)) is not greater than (K_B = 200), and
•  \(\frac{K_B}{\beta} \approx 153.85 \)  is indeed greater than (K_A = 150), it meets the criteria for species B winning according to the Lotka-Volterra model.

Conclusion:

Therefore, the outcome of competition will be Species B wins.

The correct answer is Option 3 i.e. Sympatric speciation occurs within one continuously distributed population.

Explanation-

• Sympatric speciation does not require large-scale geographic distance to reduce gene flow between parts of a population. Merely exploiting a new niche may automatically reduce gene flow with individuals exploiting the other niche. This may occasionally happen when, for example, herbivorous insects try out a new host plant.
• Sympatric speciation is the evolutionary process whereby species are formed from a single ancestral species while inhabiting the same geographic area.
• In contrast to allopatric speciation, the distribution ranges of species which evolve through sympatry may be identical or they may only overlap. Rather than geographic distance prompting a reduction of gene flow between populations, sympatry occurs when members of one population make use of a new niche. Hence this population is fragmented due to the choices of different niche.