Biology

Organisms and Populations

Question:

Discuss the various types of positive interactions between species.

Answer:

Both the species benefit in mutualism. The interaction where one species is benefitted and the other is neither benefitted nor harmed is called commensalism.
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Organisms and Populations

Q 1.

What is homeostasis?

Q 2.

Why do all the fresh water organisms have contractile vacuoles whereas , majority of marine organisms lack them?

Q 3.

Lianas are vascular plants rooted in the ground and maintain erectness of their stem by making use of other trees for support. They do not maintain direct relation with those trees. Discuss the type of association the lianas have with the trees.

Q 4.

Define zero population growth rate'. Draw an age pyramid for the same.

Q 5.

Define stenohaline species.

Q 6.

What is Mycorrhiza?

Q 7.

Define the following terms and give one example for each:
(a)Commensalism (b)Parasitism
(c)Camouflage (d)Mutualism
(e)Interspecific competition

Q 8.

Species that can tolerate narrow range of temperature are called

Q 9.

Give a suitable example for commensalism.

Q 10.

Give one example for each of the following types.
(a) Migratory animal (b) Camouflaged animal
(c) Predator animal (d) Biological control agent
(e) Phytophagous animal (f) Chemical defense agent

Q 11.

In a pond, we see plants which are free-floating; rooted-submerged; footed emergent; rooted with floating leaves. Write the type of plants against each of them.
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Q 12.

Do you agree that regional and local variations exist within each.biome? Substantiate your answer with suitable example.

Q 13.

Name important defence mechanisms in plants against herbivory.

Q 14.

Give the scientific names of any two micro organisms inhabiting the human intestine.

Q 15.

What is the ecological principle behind the biological control method of managing with pest insects?

Q 16.

What are Eurythermic species?

Q 17.

What is commensalism?

Q 18.

What is high altitude sickness? Write its symptoms.

Q 19.

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a. Label the three tiers 1, 2, 3 given in the above age pyramid.
b. What type of population growth is represented by the above age pyramid?

Q 20.

If a marine fish is placed in a fresh water aquarium, will the fish be able to survive? Why or why not?

Q 21.

What is the interaction between two species called?

Q 22.

What would be the growth rate pattern, when the resources are unlimited?

Q 23.

Define aestivation.

Q 24.

What is diapause and its significance?

Q 25.

If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?

Q 26.

Write a short note on
(a)Adaptations of desert plants and animals
(b)Adaptations of plants to water scarcity
(c)Behavioural adaptations in animals
(d)Importance of light to plants
(e)Effect of temperature or water scarcity and the adaptations of animals.

Q 27.

What are the organisms that feed on plant sap and other plant parts called?

Q 28.

In an association of two animal species, one is a termite which feeds on wood and the other is a protozoan Trichonympha present in the gut of the termite. What type of association they establish?

Q 29.

The following diagrams are the age pyramids of different populations. Comment on the status of these populations.
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Q 30.

Last the attributes that populations but not individuals possess.

Q 31.

Define population and community.

Q 32.

List any three important characteristics of a population and explain.

Q 33.

In an aquarium two herbivorous species of fish are living together and feeding on phytoplanktons. As per the Gause's Principle, one of the species is to be eliminated in due course of time, but both are surviving well in the aquarium. Give possible reasons.

Q 34.

An orchid plant is growing on the branch of mango tree. How do you describe this interaction between the orchid and the mango tree?

Q 35.

Why are coral reefs not found in the regions from. West Bengal to Andhra Pradesh but are found in Tamil Nadu and on the east coast of India?

Q 36.

In an association of two animal species, one is a termite which feeds on wood and the other is a protozoan Trichonympha present in the gut of the termite. What type of association they establish?

Q 37.

Fill in the blanks:
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Q 38.

Observe the set of 4 figures A, B, C and D, and answer the following questions: •
(i) Which one of the figures shows mutualism?
(ii) What kind of association is shown in D?
(iii) Name the organisms and the association in C.
(iv) What role is the insect performing in B?
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Q 39.

Species that can tolerate wide range of salinity are called .

Q 40.

Name the association in which one species produces poisonous substance or a change in environmental conditions that is harmful to another species.

Q 41.

Why do high altitude areas have brighter sunlight and lower temperatures as compared to the plains?

Q 42.

What is brood parasitism? Explain with the help of an example.

Q 43.

Define ectoparasite and endoparasite, and give suitable examples.

Q 44.

A population of Paramoecium caudatum was grown in a culture medium. After 5 days the culture medium became pvercrowded with Paramoecium and had depleted nutrients. What will happen to the population and what type of growth curve will the population attain? Draw the growth curve.

Q 45.

Most living organisms cannot survive at temperature above 45 °C. How are some microbes able to live in habitats with temperatures exceeding 100 °C?

Q 46.

With the help of suitable diagram describe the . ; logistic population growth curve.

Q 47.

Comment on the growth curve given below.
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Q 48.

Discuss the various types of positive interactions between species.

Q 49.

While living in and on the host species, the animal parasite has evolved certain adaptations. Describe these adaptations with examples.

Q 50.

Which element is responsible for causing soil salinity? At what concentration does the soil become saline?