Free Objective Test 02 Practice Test - 11th and 12th
Question 1
Read the statements A and B. Identify the correct option.
Statement A: Diversity observed in an entire geographical area is called gamma diversity.
Statement B: Biodiversity decreases as you move from a higher altitude towards a lower altitude.
Both the statements A and B are correct
Both the statements A and B are wrong
Statement A is correct, B is wrong
Statement B is correct, A is wrong
SOLUTION
Solution : C
Gamma diversity is the diversity of an entire landscape and not just a small portion of a local ecosystem. Moreover, biodiversity tends to increase when you compare that in the lower altitudes to that in the higher altitudes.
Question 2
Which of the following is responsible for the extinction of animals?
Habitat Loss
Alien Species Invasion
Co-extinction
Endemism
SOLUTION
Solution : A and B
Habitat loss is a major reason for the extinction of animals. Large scale destruction of forests has left animals without their natural habitats, thus leading to their extinction. Alien species invasion is also a reason for the extinction of certain species. This happens especially when the alien species is more aggressive in capturing the habitat than the indigenous species.
Question 3
In the core area (or zone) of a National Park/Tiger Reserve
Human activities are permitted
Regulated human activities are permitted
Human activities are totally banned
Activities pertaining to research are permitted
SOLUTION
Solution : C
The core area of a National Park or Tiger Reserve is cut off from any sort of human contact. These places are part of the dense forest, and human intervention could lead to unwanted confrontation between man and animal.
Question 4
In India, we find mangoes with different flavours, colours, fibre content, sugar content and even shelf life. Such large variation is on account of
Species diversity
Induced mutations
Genetic diversity
Hybridisation
SOLUTION
Solution : C
Genetic diversity in an ecosystem could lead to the formation of new species or at least new characters. A particular species can have individuals with different features due to the subtle difference in their genetic makeup.
Question 5
A species is categorised as endemic because it is
Exotic and established
Kept in captivity for breeding
Exclusively found in a zone
Extinct due to calamity
SOLUTION
Solution : C
Humans are found globally in almost all parts of the world. But unlike humans, most animals and plants are restricted to certain specific geographical locations only. These species rarely survive when they are taken out of their natural habitat. Due to such high specificity of its natural habitat, a species is said to be endemic to a particular geographical location.
Question 6
The most important reason for the establishment of National Parks and Wildlife Sanctuaries is
Conservation of wildlife
Spreading awareness about wildlife
Preventing wild animals from entering villages
Studying wildlife Biology
SOLUTION
Solution : A
National Parks and Wildlife Sanctuaries are established to mark a safe zone for wildlife. These areas are closely protected by the forest department officials and help in the conservation of wildlife.
Question 7
When large numbers of deer were killed for sport and meat, the number of lions also started to decrease. If the deer were to go extinct, the lions would also die off. This phenomenon is called _______.
Habitat loss
Food chain disruption
Co-extinction
Over-exploitation
SOLUTION
Solution : C
Lions depend on deer for their food. If the population of deer disappeared, the lions would have not enough food to consume and could face the threat of extinction. Such a phenomenon wherein two species go extinct together is called co-extinction.
Question 8
How did the passenger pigeon go extinct?
Due to disease
Over-exploitation of passenger pigeons for meat, sport and feather
Excessive predation by the Bald Eagle
Severe famine resulted in the death of passenger pigeons
SOLUTION
Solution : B
Passenger pigeons were found in over billions of numbers in the United States. In just fifty years, the passenger pigeons drastically reduced in number from over billions to zero. These birds were hunted relentlessly for meat, sport and feathers to satisfy human greed.
Question 9
Arthropods make up around
SOLUTION
Solution : Arthropods or insects are the major kind of life forms present on earth. They make up 80% of the all invertebrate species that have been documented so far. Till date, about 950,000 species of arthropods have been documented.
Question 10
Regarding the assertion and reason, select the correct option:
Assertion [A]: There is a direct correlation between plant diversity and presence of pollinators.
Reason [R]: Pollination is the process by which pollen is transferred to the stigma through pollinators like bees, birds and wind.
SOLUTION
Solution : A
The assertion is true that there is a direct correlation between diversity and the presence of pollinators because pollinators like bees and birds travel from plant to plant for feeding on berries or collection of nectar and in turn, facilitate pollination by transferring pollen from one plant to the other. This increases cross-pollination and ensures a high degree of diversity in new saplings.
Question 11
The diversity of insects ___.
SOLUTION
Solution : B and E
Biodiversity exhibits a latitudinal gradient, that is, species richness decreases as you move away from the equator to the poles, or in other words, increases as you move towards the equator. Species richness is defined as the number of species per unit area. However, there are some exceptions. The Saharan desert for instance, lies nearer to the equator than the temperate zones, but shows comparatively much lower biodiversity. Nevertheless, tropics have higher biodiversity than other regions on the planet.
Question 12
Explain the term ‘explored area’.
SOLUTION
Solution : B
Explored area is the area that has been explored or colonised by organisms. It is different from the total area, in that regions that are not colonised or have not been explored do not form part of the explored area.
Question 13
What are the major causes of extinction?
Habitat loss and fragmentation
Over-exploitation
Co-extinction
SOLUTION
Solution : A, B, C, and D
There are many reasons why species go extinct. Natural disasters can cause mass extinctions. Apart from this, species go extinct at a natural rate. The four major reasons of extinction (The Evil Quartet) today are all due to human activities; these include habitat loss and fragmentation, over-exploitation, invasion of alien species and co-extinction.
Question 14
The World Summit on Sustainable Development to reduce biodiversity losses at global and local levels was held in 2002 in ___.
SOLUTION
Solution : C
At the World Summit on Sustainable Development, held in Johannesburg, South Africa in 2002, biological diversity was addressed as the primary topic. The Summit also endorsed the target to achieve by 2010 - a significant reduction in the rate of biodiversity loss at global, regional and national levels as a contribution to poverty alleviation and to the benefit of all life on earth.
Question 15
Cichlid species became extinct from
SOLUTION
Solution : A
Cichlid species became extinct from Lake Victoria because of invasion by the predatory fish Nile perch. The Nile perch was an alien species that was introduced into the lake to improve fishing. However, this resulted in the extinction of the native cichlid fish. Cichlids were detritivores and hence, their extinction caused deterioration of the lake.