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Q1. The population limited to a particular geographical area is called

• Pandemic
• Endemic
• Alien
• Natural

Solution

The population limited to a particular geographical area is called an endemic population.

Q2. Which of the following is a migratory animal?

• Siberian crane
• Fur seal
• Anguilla (eel)
• All of the above

Solution

Migration is the two-way movement of organisms of a population for adjusting to seasonal changes. Some organisms which show migration are Siberian crane, fur seal, elk and Anguilla (eel).

Q3. The relationship between a commensal and the host corresponds to

• Neutralism
• Commensalism
• Parasitism
• Mutualism

Solution

The relationship between the commensal and the host is called commensalism. It involves the association of two species of which one is benefitted and the other is not affected. The species which is benefitted is called commensal, and the other species is termed host.

Q4. When the number of immigration and births is more than emigration and deaths, the growth curve of the population will show

• Exponential phase
• Lag phase
• Declining phase
• Steady phase

Solution

From the above statement, it is clear that if the number of immigration and births is more than emigration and death, the rate of population increases and attains full potential rate.

Q5. Which of the following is a hyperparasite?

• Mosquito
• Plasmodium
• Amoeba
• Cuscuta

Solution

A hyperparasite is a parasitic organism which lives on another parasite. Plasmodium is a parasite which lives in the female Anopheles mosquito, which itself is a parasitic organism.

Q6. Bombykol is a pheromone secreted by

• Female ant
• Male ant
• Female silk moth
• Male silk moth

Solution

Bombykol is a pheromone secreted by the female silk moth to attract male silk moths for mating.

Q7. The plants of this group are adapted to live partly in water and partly above the substratum and free from water:

• Xerophytes
• Thallophytes
• Helophytes
• Hydrophytes

Solution

Plants which grow in marshes, are partly submerged in water and regrow from the substratum are called helophytes.

Q8. Excessive aerenchyma is a characteristic feature of

• Heliophytes
• Xerophytes
• Mesophytes
• Hydrophytes

Solution

The presence of excessive aerenchyma in hydrophytes helps to transport oxygen produced during photosynthesis to various parts of the plant, including roots. So, the hydrophytes have inflated organs to store air.

Q9. An association between two individuals or populations where both are benefitted and where neither can survive without the other is

• Commensalism
• Amensalism
• Protocooperation
• Mutualism

Solution

Mutualism is when two individuals are benefitted from each other. One obtains food and the other provides protection.

Q10. Xerophytes are mostly

• Succulents
• Water related
• Mesophytes
• None of the above

Solution

Xerophytes grow in water-deficient regions and dry climate. Succulents are fleshy xerophytes which absorb large quantities of water during the rainy season and store it in different body parts of the plant. Examples: Opuntia and Aloe

Q11. A large regional unit characterised by a major vegetation type and associated fauna found in a specific climate zone constitutes

• Ecosystem
• Biological community
• Biome
• Habitat

Solution

A large regional unit delimited by a specific climatic zone and having a particular major vegetation zone and associated fauna is called biome. Examples: Tundra, desert and tropical rainforest

Q12. The formula for exponential population growth is

• dN/dt = r N
• dt/dN = r N
• dN/rN = dt
• r N/dN = dt

Solution

Exponential growth of population is denoted by the formula: dN/dt = r N, where N represents the total population, r represents the rate of increase of population and dN/dt is the increase or decrease in the total population over a certain period.

Q13. Which of the following is a partial root parasite?

• Sandal wood
• Mistletoe
• Orobanche
• Ganoderma

Solution

Partial root parasites are plants which grow on the roots of other plants. The roots of the plant attack the roots of host trees and nutrients are absorbed from them. Example: Sandal wood tree grows on the roots of Eucalyptus deriving nutrition from it.

Q14. Which one of the following in one of the characteristics of a biological community?

• Sex-ratio
• Stratification
• Natality
• Mortality

Solution

Sex ratio, natality and mortality are characteristics of population. Stratification, on the other hand, is a structural component of biological community.

Q15. With respect to breeding cycles, which of the following is a day-neutral animal?

• Guinea pig
• Deer
• Sheep
• Goat

Solution

With respect to breeding cycles, guinea pigs and ground squirrels are examples of day-neutral animals.

Q16. Adamsia palliata is the scientific name for

• Sea anemone
• Hermit crab
• Lichen
• Termite

Solution

Adamsia palliata is the scientific name for sea anemone. It lives in a mutualistic relation with the hermit crab Pagurus prideaux.

Q17. The praying mantis is a good example of

• Camouflage
• Mullerian mimicry
• Warning colouration
• Social insects

Solution

The praying mantis is a predatory insect which feeds on other insects. Its shape and colour is a good example of camouflage by mimicry. It changes its colour according to the surrounding environment thus escaping from the predators.

Q18. Which one of the following is most appropriately defined?

• Host is an organism which provides food to another organism.
• Amensalism is a relationship in which one species is benefitted and the other is unaffected.
• Predator is an organism which catches and kills other organisms for food.
• Parasite is an organism which always lives inside the body of other organisms and may kill it.

Solution

The most clear and appropriate phrase is Predator is an organism which catches and kills other organisms for food. This association among the species is called predation, and the species which is caught is called prey.

Q19. In a population curve, the rate of growth becomes steady towards the end of the exponential curve due to

• Reproductive power is reduced
• Environmental stress
• Migration
• All of the above

Solution

The growth rate slows down from the exponential phase due to an increase in environmental stress. Environmental stress is due to many factors such as high competition for food, less space and greater mortality.

Q20. The main factor for the growth of human population in India is

• High birth rate
• Low death rate
• Lack of education
• All of the above

Solution

The growth of human population in India is a major concern which relies on many factors like high birth rate, low death rate and lack of education.

Q21. Species can be identified on the basis of

• Interbreeding
• Species diversity
• Reproductive isolation
• None of these

Solution

The biological species can be identified as groups of actually interbreeding natural populations which are reproductively isolated from other groups.

Q22. The temperate zone falls in the latitude range of

• 0-20°
• 20-40°
• 40-60°
• 60-80°

Solution

The latitude range of 0-20° is that of the tropical zone, 20-40° is that of the subtropical zone, 40-60° is that of the temperate zone and the arctic zone falls in the latitude range of 60-80°. The temperate zone has an average temperature range of 7-17°C.

Q23. Orchid growing on a mango branch is example of

• Mutualism
• Commensalism
• Predation
• Competition

Solution

Orchids grow on a mango branch to get some space to grow and it does not harm the mango tree. The mango tree is benefitted from the orchid. This is an example of commensalism.

Q24. A sedentary sea anaemone gets attached to the shell lining of hermit crab. The association is

• Ectoparasitism
• Symbiosis
• Commensalism
• Amensalism

Solution

Sea anaemone, when attached to the hermit crab, lives in an association and both are helped by each other. This is  called symbiosis or mutualism. The sea anaemone protects the hermit crab from the enemies, and in turn, the sea anaemone receives pieces of food dropped by the crab.

Q25. The zone of the atmosphere near the earth’s surface is

• Stratosphere
• Mesosphere
• Troposphere
• Thermosphere

Solution

Troposphere is the layer of atmosphere which is closest to our planet. Temperature and water vapour content in the troposphere decrease. Troposphere contains 99% of water vapour in the atmosphere.

Q26. Biological organisation starts with

• Atomic level
• Submicroscopic molecular level
• Cellular level
• Organismic level

Solution

Hierarchy in organisation from the level of biomolecules to the organismic level is called biological hierarchy or biological organisation. At the entry level, biological organisation starts at the cellular level.

Q27. In a population, unrestricted reproductive capacity is called

• Biotic potential
• Fertility
• Carrying capacity
• Birth rate

Solution

Biotic potential is when the reproductive capacity of a population increases at its maximum rate under ideal environmental conditions. For example, a single bacterium can divide after every 20 minutes under ideal laboratory conditions and can reproduce in just 36 hours, covering the entire Earth.

Q28. Cold-blooded animals fall under the category of

• Ectotherms
• Psychotherms
• Endotherms
• Thermophiles

Solution

Ectothermic animals, sometimes called 'cold blooded' animals, are poorly insulated and produce metabolic heat at a low rate. They also lose heat to cooler surroundings quickly.

Q29. Maximum growth rate occurs in the

• Senescent phase
• Lag phase
• Exponential phase
• Stationary phase

Solution

Each species takes advantage of the availability of food and other requirements of life in plenty, and there is an increase in population at the maximum rate which is called exponential phase.

Q30. Which one is the edaphic factor in biosphere?

• Light
• Temperature
• Water
• Soil

Solution

The edaphic factor represents the amount of soil, a major abiotic factor of the environment. It influences survival, behaviour and reproduction of organisms. The study of soil is called edaphology.

Q31. Which of the following organisms live in troops?

• Monkeys
• Lions
• Antelopes
• Locusts

Solution

Apes and monkeys live in troops. Locusts live in swarms. Lion and antelopes live in herds.

Q32. If the stronger partner is benefitted and the weaker partner is harmed, it is known as

• Symbiosis
• Predation
• Allelopathy
• Commensalism

Solution

The stronger partner kills the weaker partner and when the stronger partner is benefitted, it is said to be predation. For example, a hawk being the stronger bird kills and eats a rat which is a weak animal.

Q33. The rate of individuals born per 1,000 individuals per year is called

• Mortality rate
• Vital rate
• Natality rate
• Growth rate

Solution

The birth rate is expressed as the number of births per 1,000 individuals in the population per year. It is also called the natality rate.

Q34. Animals undergo an inactive stage during the winter known as

• Aestivation
• Hibernation
• Adaptation
• Acclimatisation

Solution

Due to cold in winter, some animals like insects and molluscs escape from the cold by hiding in caves, burrows and mud. Hibernation also includes a warm shelter, and the animal consumes stored food.

Q35. According to Allen's rule, mammals in cold regions have ____________ to conserve body heat.

• Smaller extremities (legs, tails and ears)
• Longer extremities
• Larger body mass
• Smaller body mass

Solution

To minimise heat loss, mammals in colder regions possess smaller extremities (legs, tails and ears). This is called Allen’s Rule as it was proposed by Allen.

Q36. Broad-leaved oak forests are found in

• Tropical deciduous forest
• Mediterranean evergreen forest
• Temperate deciduous forest
• North coniferous forest

Solution

Broad-leaved oak trees are dominant vegetation in the temperate deciduous forests which are found in Eastern America and New Zealand.

Q37. Which one is exclusively a xerophytic adaptation?

• Absence of stomata
• Long tap root system
• Stipular leaves
• Spines

Solution

Xerophytic adaptations are found among the most drought-resistant plants on the planet. The leaves are reduced to spines to check transpiration.

Q38. Study of trends of human population is

• Demography
• Biography
• Kalography
• Psychology

Solution

The study of structure and distribution of human population is called demography.

Q39. Human population follows the

• J-shaped growth curve
• Z-shaped growth curve
• S-shaped growth curve
• All of the above

Solution

The human population shows an S-shaped growth curve because the phases of the S-shaped growth curve show steadiness, exponential increase and equilibrium stages for the growth of the individual.

Q40. The basic unit of study in ecology is

• Population
• Organism
• Community
• Species

Solution

An organism is the foremost unit of study in ecology, followed by population, community, ecosystem and biosphere. Without an organism, ecological interaction is not possible in the environment.

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