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Environmental Issues

Long Answer Type

101.

Give reasons why:
a. Most zygotes in angiosperms divide only after certain amount of endosperm is formed.

b. Groundnut seeds are exalbuminous and castor seeds are albuminous.

c. Micropyle remains as a small pore in the seed coat of a seed.

d. Integuments of an ovule harden and the water content is highly reduced, as the seed matures.

e. Apple and cashew are not called true fruits.

1411 Views

Short Answer Type

102.

Plenty of algal bloom is observed in a pond in your locality.
(a) Write what has caused this bloom and how does it affect the quality of water.
(b) Suggest a preventive measure.

498 Views

103.

(a) List the three states the annuals and biennial angiosperms have to pass through during their life cycle.
(b) List and describe any two vegetative propagules in flowering plants.

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104.

Describe how do ‘flocs’ and ‘activated sludge’ help in sewage treatment.

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105.

Explain the role(s) of the following in biotechnology.
(a) Restriction endonuclease
(b) Gel-electrophoresis
(c) Selectable markers in pBR322

447 Views

Long Answer Type

106.

Public all over India is very much concerned about the deteriorating air quality in large parts of North India. Alarmed by this situation the Resident’s Welfare Association of your locality organised an awareness programme entitled ‘Bury not burn’. They invited you, being a biology student to participate.
(a) How would you justify your arguments that promote burying and discourage burning?
(Give two reasons)
(b) With the help of flow charts, one for each practice, depict the chain of events that follow.

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Short Answer Type

107.

List four benefits to human life by eliminating the use of CFCs .

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108.

Secondary treatment of the sewage is also called Biological treatment. Justify this statement and explain the process

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109.
How did a citizen group called Friends of Arcata Marsh, Arcata, California, USA, help to improve water quality of the marshland using Integrated Waste Water Treatment ? Explain in four steps.

Wastewater including sewage can be treated in an integrated manner, by utilising a mix of natural and artificial processes.

The conventional sedimentation, filtering and chlorine treatments are given. After this stage, lots of dangerous pollutants like dissolved heavy metals still remain.
To combat this, an innovative approach was taken and the biologists developed a series of six connected marshes over 60 hectares of marshland.
Appropriate plants, algae, fungi and bacteria were seeded into this area, which neutralises, absorb and assimilate the pollutants. Hence, as the water flows through the marshes, it gets purified naturally.
The marshes also constitute a sanctury, with a high level of biodiversity in the form of fishes, animals and birds.

110.

Looking at the deteriorating air quality because of air pollution in many cities of the country, the citizens are very much worried and concerned about their health. The doctors have declared a health emergency in the cities where the air quality is very severely poor.

(a) Mention any two major causes of air pollution.

(b) Write the two harmful effects of air pollution on plants and humans.

(c) As a captain of your school Eco-club, suggest any two programmes you would plan to organise in the school so as to bring awareness among the students on how to check air pollution in and around the school