Tag: environmental conservation and biodiversity

Questions Related to environmental conservation and biodiversity

Which of the following is the most important cause of animals and plants being driven to extinction?

zoology biodiversity, classification and conservation biodiversity losses biodiversity loss and need for conservation environmental conservation and biodiversity

  1. Co-extinctions

  2. Over-exploitation

  3. Alien species invasion

  4. Habitat loss and fragmentation

Show answer
Correct Option: D
Explanation:

  • When there are no more individuals of a species (plant or animal) alive anywhere in the world, the species is said to be extinct. Extinction is also known as the process of dying out. 

  • The process is a completely natural part of evolution. But sometimes extinctions happen at a higher and a faster rate than usual. 

  • Factors such as large body size, habitat loss, and fragmentation (a most important factor), small population and position at a higher trophic level favor extinction.

So, the correct answer is 'Habitat loss and fragmentation'.

A very small population of a species faces a greater threat of extinction than a larger population. Which of the following is suitable genetic explanation?

zoology biodiversity, classification and conservation biodiversity losses biodiversity loss and need for conservation environmental conservation and biodiversity

  1. Fewer individuals in a species impose extensive inbreeding among them.

  2. This limits the appearance of variations and puts the species at a disadvantage, if there are changes in the environment.

  3. Since, the individuals fail to cope up with the environmental changes, they may become extinct.

  4. All of the above.

Show answer
Correct Option: D
Explanation:

Smaller population faces more risk of extinction than larger population. Smaller population faces more random fluctuation, which may result in greater death rate than birth rate and that ultimately leads to their extinction. Moreover, in smaller population, more inbreeding occurs between the individuals of a population, that leads to decrease in population's potential by letting the expression of harmful mutations through heterozygosity. In smaller population, amount of accumulated variation is lesser than in larger population. Variation help in survival of population under changed environmental conditions.

Thus, the correct answer is option D.

Which among the following is mainly responsible for the extinction of wildlife? 

zoology biodiversity, classification and conservation biodiversity losses biodiversity loss and need for conservation environmental conservation and biodiversity

  1. Pollution of air and water

  2. Hunting for flesh

  3. Destruction of habitat

  4. All of the above

Show answer
Correct Option: D
Explanation:

Wildlife is an asset for our environment. It needs to be protected to maintain an optimum biodiversity. Some of the reasons for extinction of wild life are:

Destruction of their natural habitats by environmental pollution, deforestation, soil erosion, overgrazing, increased urbanization, forest fires, and developmental works.
Over exploitation of the natural resource, that is pollution of air and water.
Indiscriminate hunting that is hunting for flesh and international trade in rare animals.
Therefore, the correct answer is option D.

Biosphere reserves are being threatened with

zoology biodiversity, classification and conservation biodiversity losses biodiversity loss and need for conservation environmental conservation and biodiversity

  1. Growth

  2. Rains

  3. Pollution

  4. All of the above

Show answer
Correct Option: C
Explanation:

A biosphere reserve is a protected area for the conservation of ecosystems and genetic diversity. The biosphere reserves are formulated in order to protect the endangered and endemic plants and animals. There are certain factors which affect the nature of these reserves. Pollution results in the decrease in the number of the species. The exposure to the pollutants may develop diseases and other problems in the organisms. There is degradation of the land and the atmosphere due to the disposal of wastes which in turn affects the area under reserves. 

Thus, the correct answer is option C.

Which of the following statements best explains the fact that 99.9% of all species that have ever existed on planet earth are now extinct?

zoology biodiversity, classification and conservation biodiversity losses biodiversity loss and need for conservation environmental conservation and biodiversity

  1. Climate changes associated with large comet or asteroid impacts occur faster than organisms can change themselves and adapt to the new environmental conditions.

  2. Genetic variations within a population occur through random mutations and given enough time, the environment will change in such a way that no existing genetic-based phenotypes permit survival.

  3. The accumulation of random mutations in the genome of all organisms eventually leads to frameshift mutations in critical genes and are ultimately lethal.

  4. The rapid increase in global temperatures in the past 100 years, combined with ocean acidification, heavy metal contamination, and ozone depletion caused by human activities have caused 99.9% of all of Earth's species to go extinct.

  5. All of the above

Show answer
Correct Option: E
Explanation:
The extinction of species can occur due to various reasons, organisms not being able to adapt to changing climatic conditions, human activities, genetic mutations that did not favor the survival of the species
So, the correct answer is 'All of the above'

Scientists believe that the Hawaiian island chain as it currently exists was formed as sea-floor spreading caused the Earth's crust to slowly move over a stationary point of volcanic activity in the mantle of the Earth.
While above the area of activity, volcanic eruptions formed the islands, and as sea-floor spreading moved the newly formed island off the area of activity, other new islands formed leading to the seven islands that now exist. The largest island in the chain is the only one that is currently volcanically active, suggesting that it is still above the active region on the mantel.
If this is true, which of the following should be observed?

zoology biodiversity, classification and conservation biodiversity losses biodiversity loss and need for conservation environmental conservation and biodiversity

  1. Species on the largest island will be more closely related to those of more distant islands than to those of closer islands.

  2. The largest island will have an extensive fossil record.

  3. The largest island should have less biodiversity than the other islands.

  4. Evidence of adaptive radiation should be most observable on the oldest of the seven islands.

Show answer
Correct Option: C
Explanation:
The island that is volcanically active will not have organisms inhabiting the area, those that may inhabit will burnt or turned into ashes so, there are no chances of having a fossil record. However due to periodic volcanic activity the island will have reduced biodiversity
So, the correct answer is 'The largest island should have less biodiversity than the other islands'

Which one has become endangered due to extinction of Dodo (Raphus cucullatus)?

zoology biodiversity, classification and conservation biodiversity losses biodiversity loss and need for conservation environmental conservation and biodiversity

  1. Sideroxylon grandiflorum

  2. Chrysanthemum

  3. Cinchona

  4. Bacillus thuringiensis

Show answer
Correct Option: A
Explanation:

Sideroxylon grandiflorum is a long-lived tree in the family Sapotaceae, endemic to Mauritius. It is also known as tambalacoque or dodo tree. It is valued for its timber. Stanley Temple hypothesized that the dodo, which became extinct in the 17th century, ate tambalacoque fruits, and only by passing through the digestive tract of the dodo could the seeds germinate. Thus, due to the extinction of the dodo, the tree has become endangered. So, the correct answer is 'Sideroxylon grandiflorum'.

Population of California Candor is declining due to

zoology biodiversity, classification and conservation biodiversity losses biodiversity loss and need for conservation environmental conservation and biodiversity

  1. Increasing pollution

  2. Increasing cleanliness

  3. Increasing pesticide concentration

  4. Change in surroundings

Show answer
Correct Option: A
Explanation:

The California condor is a New World vulture, the largest North American land bird. It became extinct in the wild in 1987, but the species has since been reintroduced to northern Arizona and southern Utah, the coastal mountains of central and southern California, and northern Baja California. As condors forage exclusively on dead animals, they are especially susceptible to lead exposure from carcasses which are left in the field. Lead poisoning from spent ammunition is the number one cause of death among endangered condors in the wild.

So, the correct answer is 'Increasing pollution'.

A weed, which has invaded many forest lands of India is

zoology biodiversity, classification and conservation biodiversity losses biodiversity loss and need for conservation environmental conservation and biodiversity

  1. Parthenium hysterophorus

  2. Chenopodium album

  3. Lantana camara

  4. Eichhornia crassipes

Show answer
Correct Option: C
Explanation:
Lantana camara  is a noxious weed of South American origin. It was introduced in India as garden ornamental but now it has invaded all tropical and sub tropical areas, mainly forests of India.
So, the correct answer is 'Lantana camara'.