Tag: zoology

Questions Related to zoology

Which of the following is considered during natural selection?

  1. Genetic variation

  2. Differential reproduction

  3. Competition

  4. All of the above


Correct Option: D
Explanation:

Natural selection:- The basic mechanisms of evolution, along with mutation, migration, and genetic drift. Darwin's grand idea of evolution by natural selection is relatively simple but often misunderstood. To find out how it works, imagine a population of beetles: There is variation in traits.

So, the correct answer is "All of the above".

In a habitat, there are red bugs and green bugs. The birds prefer the taste of the red bugs, so soon there are many green bugs and few red bugs. The green bugs reproduce and make more green bugs and eventually there are no more red bugs. The given example can be related to 

  1. Adaptive radiation

  2. Natural selection

  3. Genetic variation

  4. All of the above


Correct Option: B
Explanation:

The given example is of natural selection. According to the theory of natural selection, nature supports the survival of the fittest. It means, only those individuals will survive, who adapt themselves to the change in the environment. In the given case, bugs adapted the green colouration to survive. They were selected by the nature as fittest. So, the correct option is B.

The species which were not able to adapt to their environments through genetic changes to their skeletons were not able to survive. The given statement is an example of 

  1. Skeletal Adaptations

  2. Coloration

  3. Physiological adaptations

  4. All of the above


Correct Option: A
Explanation:

The given adaptation in lizard is an example of skeletal adaptation of natural selection. According to this adaptation, the individual who didn't develop the skeletal changes died. This type of adaptation can be seen in some species (lizards, giraffes) of animals who adapted themselves to the environment through genetic changes in their skeletons. For example, development of long neck in giraffes to reach food sources of the upper part of the trees. It is said that those died who didn't develop the long neck. Another example is development of longer leg bones in lizards to help them to climb up during periods of flood and to escape predators in the ground. Those lizards who didn't develop long leg bones, died. So, the correct option is A.

Which of the following has a natural selection as principle mechanism?

  1. Adaptive radiation

  2. Convergent evolution

  3. Genetic variation

  4. None of the above


Correct Option: A
Explanation:

Principle Mechanism:-

  • Variation. Organisms (within populations) exhibit individual variation in appearance and behavior.
  • Inheritance. Some traits are consistently passed on from parent to offspring.
  • High rate of population growth.
  • Differential survival and reproduction. 
  • Adaptive radiation:- A process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.  So,the correct answer is "Adaptive radiation".

The animals having several adaptation and are able to adapt is given by theory of 

  1. Evolution

  2. Natural selection

  3. Variation

  4. None of the above


Correct Option: B
Explanation:

The Central idea of Darwinism is Natural Selection. He stated that nature selects the best-suited organisms that have a greater chance to become parents for the next generation who have adapted themselves. Thus, the correct answer is option B.

The peppered moths rested became blackened by soot, giving the dark-coloured moths

  1. Advantage in hiding from predators

  2. Advantage in hiding from primary consumers

  3. Advantage in hiding from secondary consumers

  4. None of the above


Correct Option: A
Explanation:

Due to changes in the environment, the dark coloured moths had a better survival chance as compared to the light coloured moths, which could be easily spotted. Hence, dark coloured moths got an advantage in hiding from predators. Hence dark coloured moths were able to leave the greater number of progeny. In other words, dark coloured moths were naturally selected and they were reproductively successful as compared to light coloured moths.

Thus, the correct answer is option A.

Peacock females pick their mate according to the males tail. The ones with the largest and brightest tails mate more often. The given example can be related to

  1. Adaptive radiation

  2. Natural selection

  3. Convergent evolution

  4. None of the above


Correct Option: B
Explanation:

The male peacock has a lot of showy feathers.However, peacocks use their feathers to attract peahens (female peacocks). The peacocks with the showier feathers are able to attract mates, so they are the ones that have offspring, and pass on the fancy-feather genes to the next generation.

So, the correct answer is  "Natural selection".

Read the passage and answer the following question.

A total of 12 bird species having distinct diets, behavior, coloration and beak shapes inhabit a large volcanic island in the South Atlantic 500 miles from the Coast of Africa not found on the mainland. Two species are flightless herbivores. A bird found on the mainland is related to these bird species but it does not fly over water but can occasionally survive at sea in a storm. There are no reptiles, mammals or amphibians on the island, although there are many insect and plant species.

The evolution of two flightless bird species on the island indicates

  1. Flight improved the ability of the species to escape predators, but impaired food gathering on the ground.

  2. Flight originally evolved only to escape predators.

  3. Mimicry is a highly effective evolutionary strategy.

  4. The species had greater fitness without the ability to fly.

  5. Flight is not an effective means to escape predators.


Correct Option: D
Explanation:

According to Charles Darwin, Natural selection is a tool of nature to impose the survival of the fittest. As some species fight to become the fittest, they adapt. Many organisms due to this, evolved, got adapted as they chose to survive in that habitat. Adaptation is the biggest drive to evolution and the pinpointed conclusion of the natural selection. 

So, the correct option is 'The species had greater fitness without the ability to fly'.

Read the passage and answer the following question.

A total of 12 bird species having distinct diets, behavior, coloration and beak shapes inhabit a large volcanic island in the South Atlantic 500 miles from the Coast of Africa not found on the mainland. Two species are flightless herbivores. A bird found on the mainland is related to these bird species but it does not fly over water but can occasionally survive at sea in a storm. There are no reptiles, mammals or amphibians on the island, although there are many insect and plant species.

Two of the bird species on the island are herbivores that both inhabit the same species of tree and eat the fruit the tree produces year-round. Which of the following helps both species to inhabit the tree without competing for resources?

  1. One species lives in the top 30 percent of the tree and the other species lives in the lower 70 percent.

  2. One species is nocturnal and the other is active during the day.

  3. Reproductive isolation exists.

  4. The species have differing beak shapes.

  5. One species must become extinct.


Correct Option: A
Explanation:

This phenomenon is called Resource partitioning. When the resources in a niche are limited, so as to avoid the competition species divide the resources accordingly.

According to R* rule of limited resources of ecology, If two species are living in a resource limiting space, the species which can survive in the lowest equilibrium of resource will only resist the extinction. Coexistence is only possible if each species have the low R* on that resource.
So, the answer is 'One species lives in the top 30 percent of the tree and the other species lives in the lower 70 percent'.

Replacement of the lighter-coloured variety of peppered moth (Biston betularia) to its darker variety (Biston carbonaria) in England is the example of

  1. Natural selection

  2. Regeneration

  3. Genetic isolation

  4. Temporal isolation


Correct Option: A
Explanation:
In England, before industrialisation in $1860$, it was observed that there were more white-winged moths on tree trunks than dark-winged or melanised moths. But after industrialisation in $1920$, there were more dark-winged moths in the same area. Before industrialisation, the tree trunks were covered by white-coloured lichens. In that background, the white-winged moths survived but the dark-winged moths were eaten by predators. During post industrialisation period, the tree trunks became dark due to industrial smoke and soot. Therefore, the white winged moths could not survive due to predators but dark-winged moths survived, i.e., the moths that were hidden in background survived. Thus, industrial melanism supports evolution by natural selection.

So, the correct answer is 'Natural selection'.