1. Which of the following groups contain only biodegradable items?
(a) Grass, flowers and leather
(b) Grass, wood and plastic
(c) Fruit-peels, cake and
lime-juice
lime-juice
(d) Cake, wood and grass
ANSWER: – (c) Fruit-peels, cake and lime-juice
(d)
Cake, wood and grass
Cake, wood and grass
2. Which of the following constitute a
food-chain?
food-chain?
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat
ANSWER-: (b) Grass, goat and human
3. Which of the following are environment-friendly
practices?
practices?
(a) Carrying cloth-bags to put purchases in while
shopping
shopping
(b) Switching off unnecessary lights and fans
(c) Walking to school instead of getting your mother
to drop you
on her scooter
to drop you
on her scooter
(d) All of the above
ANSWER :- ( d) All of the above
4. What will happen if we kill all the organisms in
one trophic level?
one trophic level?
ANSWER:-If
we kill all the organisms of one
trophic level it will create an imbalance in the ecosystem.
we kill all the organisms of one
trophic level it will create an imbalance in the ecosystem.
5.
Will the impact of removing all
the organisms in a trophic level
be different for different trophic
levels? Can the organisms
of any trophic level be
removed without causing any
damage to the ecosystem?
Will the impact of removing all
the organisms in a trophic level
be different for different trophic
levels? Can the organisms
of any trophic level be
removed without causing any
damage to the ecosystem?
ANSWER:-Impact
of removing all organisms
of a trophic level is different
for different trophic levels.
For example, if we remove producers
from a food chain, no
organism will get food, if we
remove herbivores from a food
chain then carnivores will die
and producers will also die due
to competition for space and
nutrients. No, we can’t remove any trophic level without causing damage to the
ecosystem as one is dependent on other for their survival. If we remove any one
this will create imbalance in the ecosystem.
of removing all organisms
of a trophic level is different
for different trophic levels.
For example, if we remove producers
from a food chain, no
organism will get food, if we
remove herbivores from a food
chain then carnivores will die
and producers will also die due
to competition for space and
nutrients. No, we can’t remove any trophic level without causing damage to the
ecosystem as one is dependent on other for their survival. If we remove any one
this will create imbalance in the ecosystem.
6. What is biological
magnification? Will the levels of this magnification be different at different
levels of the ecosystem?
magnification? Will the levels of this magnification be different at different
levels of the ecosystem?
ANSWER:-Biological
magnification is defined as the phenomena of accumulation
or increase in the
concentration of some toxic
substances at each trophic
level. The levels of bio-magnifications will be different at different trophic levels. For example, in a pond of water, DDT was sprayed and the producers were found to have 0.04 ppm concentration of DDT. Since many types of planktons are eaten by some fishes and clams, their body accumulates 0.23 ppm of DDT. Sea gull that feeds on clams accumulates more DDT as one sea gull eats many clams. Hawk, the top carnivore, has the highest concentration of DDT.
magnification is defined as the phenomena of accumulation
or increase in the
concentration of some toxic
substances at each trophic
level. The levels of bio-magnifications will be different at different trophic levels. For example, in a pond of water, DDT was sprayed and the producers were found to have 0.04 ppm concentration of DDT. Since many types of planktons are eaten by some fishes and clams, their body accumulates 0.23 ppm of DDT. Sea gull that feeds on clams accumulates more DDT as one sea gull eats many clams. Hawk, the top carnivore, has the highest concentration of DDT.
7. What are the problems caused by the non-
biodegradable wastes that we generate?
biodegradable wastes that we generate?
ANSWER: – → The
cause bio-magnifications.
cause bio-magnifications.
→ They increase pollution.
→ They make environment
unclean.
unclean.
→ They kill useful
microorganisms.
microorganisms.
8. If all the waste we generate is biodegradable, will
this have no
impact on the environment?
this have no
impact on the environment?
ANSWER:-If
all the waste generated would be biodegradable this will also create problem.
As the numbers of decomposers will be quite low so wastes cannot be broken down
into harmless simpler substance at right time. It will become breeding ground for flies causing spread of diseases.
all the waste generated would be biodegradable this will also create problem.
As the numbers of decomposers will be quite low so wastes cannot be broken down
into harmless simpler substance at right time. It will become breeding ground for flies causing spread of diseases.
9.
Why is damage to the ozone layer
a cause for concern? What steps are being taken to limit this damage?
Why is damage to the ozone layer
a cause for concern? What steps are being taken to limit this damage?
ANSWER:-The damage to the ozone
layer a cause for concern because:
layer a cause for concern because:
→ It
causes skin darkening, skin cancer, ageing, and corneal cataracts in human
beings.
causes skin darkening, skin cancer, ageing, and corneal cataracts in human
beings.
→ It
can result in the death of many
phytoplankton that leads
to increased global warming.
can result in the death of many
phytoplankton that leads
to increased global warming.
To
limit the damage to the ozone layer, the release of CFCs into the atmosphere
must be reduced. CFCs used as refrigerants and in fire extinguishers should be replaced with
environmentally-safe alternatives.
limit the damage to the ozone layer, the release of CFCs into the atmosphere
must be reduced. CFCs used as refrigerants and in fire extinguishers should be replaced with
environmentally-safe alternatives.