CUSTOMER_CODE
SMUDE
DIVISION_CODE
SMUDE
EVENT_CODE
OCTOBER15
ASSESSMENT_CODE BJ0056_OCTOBER15
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
15295
QUESTION_TEXT
What are Grassland? Enumerate their types and features.
SCHEME OF
EVALUATION
Grassland ecosystems are constituted by big open spaces that do not
have many bushes. Trees are present only by the side of rivers and
steams. A grassland appears like an endless sea of grass. On an average,
grasslands receive about 10 to 30 inches of rain per year. If they were to
experience more rain, the grasslands would become a forest. And if they
get less rain, they would become a desert.
Two main types of grasslands ecosystems are:
*Tropical grassland: (Explanation)
*Temperate grassland: (Explanation)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
15299
QUESTION_TEXT
Explain the role of Forests in the Environment.
SCHEME OF
EVALUATION
Besides the products that they provide, forests play a vital role in the
environment
(1 mark)
a.Watershed protection: Forest areas attract heavy rainfall and control
floods by intercepting surface runoffs, infiltration, evaporation and thus
help in water retention of soil and in recharging ground water resources
(2 marks)
b.Soil conservation: Forests affect the composition, structure and
chemical properties of soil
(1 mark)
c.Control of green house effect: The green leaves and stems of plants
absorb carbon dioxide from the atmosphere and regulate the greenhouse
effect
(2 marks)
d.Climate control: Plants absorb and transform radiant energy into plant
biomass, store carbon dioxide, water and minerals and release oxygen,
which in turn regulates the climate
(2 marks)
e.Pollution reduction: Forests soil and vegetation act as an effective
absorbent for a large number of pollutants and thus reduce pollutant in
the environment
(2 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
15300
QUESTION_TEXT
Explain Food Chain.
SCHEME OF
EVALUATION
The green plants convert solar energy to chemical energy with the help
of inorganic substances such as water, carbon dioxide, as well as other
nutrients and store it as food material. This is utilized by plants for their
survival, which are then consumed by herbivores. The herbivores are
consumed by carnivores and carnivores by top carnivores. Through this
process, one form of life is supported by another. In other words, the
transfer of food energy from the producers, through a series of organisms
with repeated eating and being eaten, is known as food chain
(7 marks)
The arrangement in a food chain can be depicted as:
Plant→ Herbivore→ Carnivore→ Top carnivore
(3 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
73119
QUESTION_TEXT
What is meant by desert ecosystem? Briefly explain its components.
SCHEME OF
EVALUATION
Desserts are defined as regions wherein the average annual precipitation
exceeds 20 inches per year and the amount of water lost through
evapotranspiration is much more than the amount of water gained by
precipitation. Thus desert ecosystems are highly sensitive and occur in regions
that receive an annual rainfall of less than 25 cm. they occupy approximately 17
percent of all land on earth. On account of very high temperature, intense
sunlight and water scarcity, desert ecosystems have poorly developed flora and
fauna. Vegetation in deserts comprises primarily of bushes, shrubs, few
grasses and very rarely, trees. Nature has designed the roots of these plants to
be long and deep and their leaves and stems are modified to conserve water.
Common desert plants are succulents like spiny leaved cacti.
Deserts are of two types- hot deserts such as the sahara, the thar and the
Mojave and cold deserts of which the best example is Antarctica. A major
difference between hot and cold deserts is in the form of precipitation. There is
snowfall in cold deserts and rainfall in hot deserts and rainfall in hot deserts. It
may come as a surprise to you but even hot deserts have chilling temperatures
at night.
The species composition of such ecosystems is much more of us varied
and typical due to extremes of both temperature and water availability. The
different biotic components present in desert ecosystems are;
1. Producers; when it comes to desert vegetation, most of us only think of
cactus.it may come as a surprise to you that are hundreds of varieties in desert
ecosystems mainly consists of few shrubs and thromy trees. These plants have
modified themselves to sustain in the desert environment. Some plants store
water in specialized tissues while others have small leaves with hair like
structures which reduce the rate of evaporation of moisture. The shrubs have
widespread and branches root system with modified stems and branches.
Trees such as kher, babul and lower plants like lichens and xerophytes mosses
are found here.
2. Consumers; the desert and semi-arid regions have a number of highly
specialized insects and reptiles that are adapted to survive under xeric
conditions. The commonly found birds are partridge, quail and sand grouse.
Common animals are wolves, desert cats and desert foxes. Camels feed on
tender shoots of plants. The rodents, insects and reptiles which feed on desert
plants are the primary consumers. At the top of the desert food chain are the
apex predators in the form of birds and mammals.
3. Decomposers; due to poor vegetation, the amount of dead organic matter
is scanty and hence, the same is true for decomposers. There are some fungi
and bacteria that are found in deserts and most of them are thermopiles.
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
124532
QUESTION_TEXT
Write down the value of biodiversity.
1. Consumptive use
2. Productive use
3. Social value
SCHEME OF EVALUATION 4. Ethical value
5. Aesthetic value
6. Option value
(Any five 2 X 5 = 10 marks)
QUESTION_TYPE
DESCRIPTIVE_QUESTION
QUESTION_ID
124535
QUESTION_TEXT
What are the main uses of forests?
1. Timber
SCHEME OF EVALUATION 2. Fuel
3. Shelter
4. Food
5. Paper
6. Forest products
(Any five 2 X 5 = 10 marks)