Introduction to Ecosystem Structure

Q.

What are the functions of an ecosystem?

Q.

What are the nonliving parts of an ecosystem?

Q. Select the incorrect statement with respect to ecological niche.

1. It represents functional role and status of a species in the environment
2. It represents trophic position of a few species in the environment
3. It describes how an organism or population responds to the distribution of resources
4. It is a component of habitat which is governed by functioning of an organism

Q. (a) “Organisms may be conformers or regulators.” Explain this statement and give one example of each.

(b) Why are there more conformers than regulators in the animal world? [3]

Q. What is 'carrying capacity' of a species in a habitat ? Why is logistic growth model considered more realistic. [2 Marks]

Q. Introduction of prickly pear cactus in Australia in the year 1920, caused havoc by spreading rapidly into wide range of lands because

1. the invaded land did not have its natural predators
2. they formed new mutualistic relationships with the native species of cactus
3. of the presence of coevolved herbivores
4. they drained soil of all nutrients

Q. Why did conformers not evolve to become regulators?

Q.

Describe the components of an ecosystem.

Q. Which one of the following processes during decomposition is correctly described?

1. Fragments- carried out by organism such as earthworm.
2. Humification- leads to the accumulation of a dark coloured substance humus which undergoes microbial action at a very fast rate.
3. Leaching- water soluble inorganic nutrients rise to the top layers of soil.
4. Catabolism- last step in the decomposition under fully anaerobic condition.

Q. Regulators are the animals which

1. can regulate heartbeat
2. can maintain homeostasis
3. can regulate their circulatory system
4. can change their colour

Q. Differentiate between :
Biotic and abiotic components of an ecosystem

Q.

The interaction of species with the environment is called as

1. community
2. environment
3. ecosystem
4. autecology

Q.

The biotic component of the biosphere is not constituted by:

1. Producers

2. Consumers

3. Decomposers

4. Air

Q. Which one of the following is not a functional component of the ecosystem?

1. Productivity
2. Energy flow
3. Stratification
4. Decomposition

Q. Boundaries between one ecosystem and another are indistinct and overlapping. Therefore, all ecosystems on the earth are joined together to form a single global ecosystem known as

1. population
2. species
3. biosphere
4. community

Q. Why should a highly variable external environment bother organisms after all?

Q.

Give one word for the interaction of living organisms with non living environment.

Q. Which of the following ecosystems would be most stable?

1. Man made forest
2. Saline lake
3. Fresh water lake
4. Natural forest

Q. In an ecosystem, those carnivores which generally do not get preyed upon by predators are known as “top carnivores”.

1. True
2. False

Q. What will be the trophic level of a Bamboo plant that is growing far from the forest area?

1. First trophic level (T1)
2. Second trophic level (T2)
3. Third trophic level (T3)
4. Both T1 and T2

Q. Match column I with column II and choose the correct option from the given codes.

Column I	Column II
A. Population	(i) Part of the earth consisting of all the ecosystems of the world
B. Community	(ii) Assemblage of all the individuals belonging to different species occurring in an area
C. Ecosphere	(iii) Group of similar individuals belonging to the same species, found in an area
D. Ecosphere	(iv) Interaction between the living organisms and their physical environment
	(v) Classification of organisms based on the type of environment

1. A-(iv), B-(v), C-(iii), D-(i)
2. A-(iii), B-(ii), C-(i), D-(v)
3. A-(ii), B-(iii), C-(i), D-(iv)
4. A-(iii), B-(ii), C-(iv), D-(i)

Q. Stability of ecosystem depends, upon

1. Interchange between producers and consumers
2. Number of producers
3. Number of consumers
4. Primary productivity

Q. Consider the following statements regarding food chains.

1. Removal of 80% of tigers from the forest ecosystem resulted in increased growth of vegetation
2. Removal of most of the carnivores resulted in an increased population of herbivores
3. The length of food chains is generally limited to 3 – 4 trophic levels due to energy loss
4. The length of food chains may vary from 2 to 8 trophic levels

How many of the above statements are incorrect?

1. 1
2. 2
3. 4
4. 3

Q.

Apart form plants and animals, microbes from a permanent biotic component in an ecosystem. While plants have been referred to as autotroophs and animals as heterotrophs, what are microbes referred to as? How do the microbes fulfil their energy requirements?

Q. If decomposers are removed what will happen to the ecosystem?

1. Energy cycle is stopped
   
2. Mineral cycle is stopped
3. Consumers cannot absorb solar energy
4. Rate of decomposition of mineral increases

Q. The two components of biosphere are

1. Biotic and abiotic
2. Plants and animals
3. Algae and fungi
4. None of the above

Q. Biotic community along with its interacting physical environment comprises

1. Phytosociology
2. Phytogeography
3. Ecosystem
4. Ecology

Q. Which one of the following is a characteristic feature of cropland ecosystem?

1. Absence of soil organisms
2. Least genetic diversity
3. Absence of weeds
4. Ecological succession

Q. In a forest ecosystem fungi comes under

1. Secondary consumer
2. Decomposers
3. Tertiary consumer
4. Primary producers

Q. Given graph represents the response of organisms to various abiotic factors. On this basis, select the correct option for (i), (ii) and (iii)

1. Partial regulators Regulators Conformers
2. Regulators Conformers Partial regulators
3. Conformers Regulators Partial regulators
4. Regulators Partial regulators Conformers