CBSE 12th Standard Biology Subject Environmental Issues HOT Questions 2 Marks Questions 2021
QB365 Provides the HOT Question Papers for Class 12 Biology, and also provide the detail solution for each and every HOT Questions. HOT Questions will help to get more idea about question pattern in every exams and also will help to get more marks in Exams
QB365 - Question Bank Software
CBSE 12th Standard Biology Subject Environmental Issues HOT Questions 2 Marks Questions 2021
12th Standard CBSE
-
Reg.No. :
Biology
-
Study the given aquatic food chain and answer the questions that follow:
(i) Give reasons why there is a continuous increase in the DDT content in different trophic levels of the chain.
(ii) Name the phenomenon responsible for the increase in DDT content. -
During last few decades, most products are being sold in secure ‘consumer friendly’packages .
a) Should this be encouraged?
b) How are modern packaging techniques turning into a major environmental threat?
c) Give some examples where such packaging can be easily avoided. -
Why are grains and vegetables produced in organic farms supposed to be better for human consumption than those produced in farms where chemical fertilizers, pesticides etc. has been used?
-
(a) What will happen if electrode wires are not maintained at several thousand volts?
(b) The velocity of air is high -
In a survey it is observed that the population of fish-eating birds living on the bank of lake is continuously declining, where DDT is regularly sprayed to check mosquitoes.
i) What could be the reason behind this?
ii) Name the phenomenon involved. -
What in your opinion is more polluted and why – Domestic sewage or ndustrial effluents/waste from a agricultural field containing fertilizes and pesticides?
-
Why was Eichhornia introduced into India? What is the consequence of its introduction?
-
List some of the waste which is generated at home. Which of them can you avoid or reduce easily?
-
Suppose your father is planning to set up a factory.
(i) What measures would you suggest to him to provide protection against noise pollution.
(ii) Mention two harmful effects of noise pollution -
Is global warming real, only a theory or speculation?
2 Marks
*****************************************
CBSE 12th Standard Biology Subject Environmental Issues HOT Questions 2 Marks Questions 2021 Answer Keys
-
(i) The DDT concentration increases because:
1. it cannot be metabolised.
2. it is not excreted, but it is passed on to the next higher trophic level.
(ii) the phenomenon is called bio-magnification. -
a) No
b) (i) Polythene causes leakage in sewer system
(ii) If burnt, produces toxic gases and causes air pollution
c) (i) Use of cotton / jute bags, paper bags encouraged
(ii) Polythene packets can be used to make polyblend which can be used in making roads. -
Chemical fertilizers/pesticides --non -biodegradable, enter into food chain through vegetables/grains, causes biomagnification in humans. In organic farms manure is used, whose produce causes no harm to human health.
-
(a) Corona will not be formed, no release of electrons, dust particles can not be negatively charged, so can not settle down in electrostatic precipitator.
(b) Dust will not settle down. -
i) Increase in the level of DDT with each trophic level.
ii) Biomagnification. -
Wastes from agricultural field /& Industrial effluents, because they are non-Biodegradable and toxic.
-
Introduced for their lovely flowers - have caused havoc by their excessive growth and causing blocks in our waterways.
-
(a) polythene packets
(b) vegetable peels
(c) Dry cells, blades
(d) aluminium foils
(e) Pieces of glass etc. Polythene packets can be avoided by using cotton bags, jute bags etc.(or any other waste with reason) -
i) a) Planting trees around the factory.
b) Walls should be equipped with sound absorbent material.
c) Workers should be equipped with ear-muffs
ii) a) impairing hearing ability
b) b) Sleeplessness, increased heart beat. -
Global warming is real and has been with us for sometime, increasingly during the past two decades, but gradually for more than a hundred years. The reality of it is seen in direct temperature measurements and also in the melting of glaciers in low latitudes, permafrost decay in Alaska and the decrease in sea-ice cover in Arctic.
2 Marks
