CBSE Biology All India Past year paper (solutions) - 2016, Class 12 | Additional Study Material for NEET PDF Download

 Page 1


  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
CBSE 
Class XII Biology 
Board Paper 2016 – All India (Set 1)  
SOLUTION 
                                                                                                                           
SECTION A 
 
1. Male honey bees are born from unfertilised eggs, whereas female honey bees are 
born from fertilised eggs. Because the unfertilised egg carries half the number of 
chromosomes as compared to the fertilised egg, male honey bees have half the 
number of chromosomes as compared to female honey bees. 
 
2. In multiple ovulation embryo transfer (MOET), the genetic mother is administered 
with hormones which induce follicular maturation and superovulation. After 
fertilisation, the eggs are transferred to a surrogate mother at the 8 –32 cell stage for 
further development. The genetic mother can then be used for another round of 
superovulation. 
 
3. Biopiracy is the term given to unauthorised use of bioresources by multinational 
companies and other organisations without proper authorisation and compensatory 
payments to the people concerned. 
 
4. Two advantages of compressed natural gas (CNG) over diesel fuel: 
1. CNG burns more efficiently and very little residue is left unburnt. 
2. It is cheaper than diesel and chances of adulteration are negligible. 
 
5. Homo habilis did not eat meat, whereas Homo erectus was probably a meat eater.  
 
 
  
Page 2


  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
CBSE 
Class XII Biology 
Board Paper 2016 – All India (Set 1)  
SOLUTION 
                                                                                                                           
SECTION A 
 
1. Male honey bees are born from unfertilised eggs, whereas female honey bees are 
born from fertilised eggs. Because the unfertilised egg carries half the number of 
chromosomes as compared to the fertilised egg, male honey bees have half the 
number of chromosomes as compared to female honey bees. 
 
2. In multiple ovulation embryo transfer (MOET), the genetic mother is administered 
with hormones which induce follicular maturation and superovulation. After 
fertilisation, the eggs are transferred to a surrogate mother at the 8 –32 cell stage for 
further development. The genetic mother can then be used for another round of 
superovulation. 
 
3. Biopiracy is the term given to unauthorised use of bioresources by multinational 
companies and other organisations without proper authorisation and compensatory 
payments to the people concerned. 
 
4. Two advantages of compressed natural gas (CNG) over diesel fuel: 
1. CNG burns more efficiently and very little residue is left unburnt. 
2. It is cheaper than diesel and chances of adulteration are negligible. 
 
5. Homo habilis did not eat meat, whereas Homo erectus was probably a meat eater.  
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
SECTION B 
 
6. Pea plant is a dioecious plant bearing bisexual flowers, i.e. the stamen and pistil are 
present on the same flower. Thus, the single pea plant can produce viable seeds 
after self-pollination. 
 
Papaya is a monoecious plant bearing unisexual flowers and requires cross-
pollination for viable seed production. Thus, a single papaya plant cannot produce 
viable seeds. 
 
7. Features of the genetic code: 
Stop codon: Signals termination of translation and does not code for any amino acid. 
Unambiguous codon: Each codon codes for only one amino acid. 
Degenerate codon: More than one codon can code for a specific amino acid. 
Universal codon: One codon codes for the same amino acid in all species. 
 
8. Important steps involved in conventional breeding technology: 
(i) Selection of parent plant with desired combination of characters 
(ii) Hybridisation of selected plants 
(iii) Selection and evaluation of hybrids 
(iv) Testing and release of new varieties for commercial production 
 
9. Nucleopolyhedrovirus is a genus of a baculovirus which are efficient biocontrol 
agents. They are considered good biocontrol agents because they are species-
specific and have no negative impacts on plants, mammals, birds, fish or even on 
non-target insects. 
 
10. The ozone layer is getting depleted by the action of chlorofluorocarbons (CFCs) 
used as a coolant in refrigerators and in perfumes. When CFCs are released into 
the stratosphere, they end up being broken up by ultraviolet light, resulting in 
chlorine being released. Chlorofluorocarbons bind to ozone, and the chemical 
reaction releases a chlorine free-radical capable of destroying thousands of 
molecules of ozone. 
OR 
            Sacred groves are forest fragments which are highly protected by certain 
communities because they are of religious importance to these communities. 
 
 
 
 
 
 
 
Page 3


  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
CBSE 
Class XII Biology 
Board Paper 2016 – All India (Set 1)  
SOLUTION 
                                                                                                                           
SECTION A 
 
1. Male honey bees are born from unfertilised eggs, whereas female honey bees are 
born from fertilised eggs. Because the unfertilised egg carries half the number of 
chromosomes as compared to the fertilised egg, male honey bees have half the 
number of chromosomes as compared to female honey bees. 
 
2. In multiple ovulation embryo transfer (MOET), the genetic mother is administered 
with hormones which induce follicular maturation and superovulation. After 
fertilisation, the eggs are transferred to a surrogate mother at the 8 –32 cell stage for 
further development. The genetic mother can then be used for another round of 
superovulation. 
 
3. Biopiracy is the term given to unauthorised use of bioresources by multinational 
companies and other organisations without proper authorisation and compensatory 
payments to the people concerned. 
 
4. Two advantages of compressed natural gas (CNG) over diesel fuel: 
1. CNG burns more efficiently and very little residue is left unburnt. 
2. It is cheaper than diesel and chances of adulteration are negligible. 
 
5. Homo habilis did not eat meat, whereas Homo erectus was probably a meat eater.  
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
SECTION B 
 
6. Pea plant is a dioecious plant bearing bisexual flowers, i.e. the stamen and pistil are 
present on the same flower. Thus, the single pea plant can produce viable seeds 
after self-pollination. 
 
Papaya is a monoecious plant bearing unisexual flowers and requires cross-
pollination for viable seed production. Thus, a single papaya plant cannot produce 
viable seeds. 
 
7. Features of the genetic code: 
Stop codon: Signals termination of translation and does not code for any amino acid. 
Unambiguous codon: Each codon codes for only one amino acid. 
Degenerate codon: More than one codon can code for a specific amino acid. 
Universal codon: One codon codes for the same amino acid in all species. 
 
8. Important steps involved in conventional breeding technology: 
(i) Selection of parent plant with desired combination of characters 
(ii) Hybridisation of selected plants 
(iii) Selection and evaluation of hybrids 
(iv) Testing and release of new varieties for commercial production 
 
9. Nucleopolyhedrovirus is a genus of a baculovirus which are efficient biocontrol 
agents. They are considered good biocontrol agents because they are species-
specific and have no negative impacts on plants, mammals, birds, fish or even on 
non-target insects. 
 
10. The ozone layer is getting depleted by the action of chlorofluorocarbons (CFCs) 
used as a coolant in refrigerators and in perfumes. When CFCs are released into 
the stratosphere, they end up being broken up by ultraviolet light, resulting in 
chlorine being released. Chlorofluorocarbons bind to ozone, and the chemical 
reaction releases a chlorine free-radical capable of destroying thousands of 
molecules of ozone. 
OR 
            Sacred groves are forest fragments which are highly protected by certain 
communities because they are of religious importance to these communities. 
 
 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
SECTION C 
 
11.   
(a) The exine of the pollen grain is made of sporopollenin. Sporopollenin is one of 
the most resistant organic compounds. It can withstand high temperature, 
strong acids and alkalis and cannot be degraded by any of the known enzymes. 
Hence, it acts as a shield and protects the pollen grain from getting damaged. 
 
(b) Exine does not form a continuous layer around the pollen because it is absent in 
certain sections called germ pores which serve as an outlet for the formation of 
the pollen tube. 
 
(c) Pollen grains can be stored for years by cryopreservation. After this treatment, 
they are stored in pollen banks. Such conserved pollen grains can be used in 
plant breeding programmes. 
 
OR 
(a) Problems addressed through reproduction and child health care programmes: 
(i) Creating awareness among people about the various aspects related to 
reproduction. 
(ii) Providing facilities and support required for building and maintaining a 
reproductively healthy society. 
 
(b) Amniocentesis is a disorder test based on the chromosomal pattern in the 
amniotic fluid surrounding the developing embryo. It is used to detect any 
chromosomal defect in the embryo. However, recently, amniocentesis is being 
used to detect the gender of the foetus resulting in several female foeticides. This 
declines the gender ratio. Therefore, there is a statutory ban on amniocentesis to 
avoid female foeticides. 
 
12. Test cross is a cross between F 1 progeny and its homozygous recessive parent. 
This cross determines whether the dominant character is coming from 
homozygous dominant genotype or heterozygous genotype (e.g. tallness coming 
from TT or Tt). When TT is crossed with tt, we obtain all Tt (tall) individuals in the 
progeny, whereas when Tt is crossed with tt, we obtain Tt (tall) and tt (dwarf) 
individuals in the progeny. Thus, a test cross can be used to determine the 
heterozygosity of the plant. 
 
 
 
 
 
Page 4


  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
CBSE 
Class XII Biology 
Board Paper 2016 – All India (Set 1)  
SOLUTION 
                                                                                                                           
SECTION A 
 
1. Male honey bees are born from unfertilised eggs, whereas female honey bees are 
born from fertilised eggs. Because the unfertilised egg carries half the number of 
chromosomes as compared to the fertilised egg, male honey bees have half the 
number of chromosomes as compared to female honey bees. 
 
2. In multiple ovulation embryo transfer (MOET), the genetic mother is administered 
with hormones which induce follicular maturation and superovulation. After 
fertilisation, the eggs are transferred to a surrogate mother at the 8 –32 cell stage for 
further development. The genetic mother can then be used for another round of 
superovulation. 
 
3. Biopiracy is the term given to unauthorised use of bioresources by multinational 
companies and other organisations without proper authorisation and compensatory 
payments to the people concerned. 
 
4. Two advantages of compressed natural gas (CNG) over diesel fuel: 
1. CNG burns more efficiently and very little residue is left unburnt. 
2. It is cheaper than diesel and chances of adulteration are negligible. 
 
5. Homo habilis did not eat meat, whereas Homo erectus was probably a meat eater.  
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
SECTION B 
 
6. Pea plant is a dioecious plant bearing bisexual flowers, i.e. the stamen and pistil are 
present on the same flower. Thus, the single pea plant can produce viable seeds 
after self-pollination. 
 
Papaya is a monoecious plant bearing unisexual flowers and requires cross-
pollination for viable seed production. Thus, a single papaya plant cannot produce 
viable seeds. 
 
7. Features of the genetic code: 
Stop codon: Signals termination of translation and does not code for any amino acid. 
Unambiguous codon: Each codon codes for only one amino acid. 
Degenerate codon: More than one codon can code for a specific amino acid. 
Universal codon: One codon codes for the same amino acid in all species. 
 
8. Important steps involved in conventional breeding technology: 
(i) Selection of parent plant with desired combination of characters 
(ii) Hybridisation of selected plants 
(iii) Selection and evaluation of hybrids 
(iv) Testing and release of new varieties for commercial production 
 
9. Nucleopolyhedrovirus is a genus of a baculovirus which are efficient biocontrol 
agents. They are considered good biocontrol agents because they are species-
specific and have no negative impacts on plants, mammals, birds, fish or even on 
non-target insects. 
 
10. The ozone layer is getting depleted by the action of chlorofluorocarbons (CFCs) 
used as a coolant in refrigerators and in perfumes. When CFCs are released into 
the stratosphere, they end up being broken up by ultraviolet light, resulting in 
chlorine being released. Chlorofluorocarbons bind to ozone, and the chemical 
reaction releases a chlorine free-radical capable of destroying thousands of 
molecules of ozone. 
OR 
            Sacred groves are forest fragments which are highly protected by certain 
communities because they are of religious importance to these communities. 
 
 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
SECTION C 
 
11.   
(a) The exine of the pollen grain is made of sporopollenin. Sporopollenin is one of 
the most resistant organic compounds. It can withstand high temperature, 
strong acids and alkalis and cannot be degraded by any of the known enzymes. 
Hence, it acts as a shield and protects the pollen grain from getting damaged. 
 
(b) Exine does not form a continuous layer around the pollen because it is absent in 
certain sections called germ pores which serve as an outlet for the formation of 
the pollen tube. 
 
(c) Pollen grains can be stored for years by cryopreservation. After this treatment, 
they are stored in pollen banks. Such conserved pollen grains can be used in 
plant breeding programmes. 
 
OR 
(a) Problems addressed through reproduction and child health care programmes: 
(i) Creating awareness among people about the various aspects related to 
reproduction. 
(ii) Providing facilities and support required for building and maintaining a 
reproductively healthy society. 
 
(b) Amniocentesis is a disorder test based on the chromosomal pattern in the 
amniotic fluid surrounding the developing embryo. It is used to detect any 
chromosomal defect in the embryo. However, recently, amniocentesis is being 
used to detect the gender of the foetus resulting in several female foeticides. This 
declines the gender ratio. Therefore, there is a statutory ban on amniocentesis to 
avoid female foeticides. 
 
12. Test cross is a cross between F 1 progeny and its homozygous recessive parent. 
This cross determines whether the dominant character is coming from 
homozygous dominant genotype or heterozygous genotype (e.g. tallness coming 
from TT or Tt). When TT is crossed with tt, we obtain all Tt (tall) individuals in the 
progeny, whereas when Tt is crossed with tt, we obtain Tt (tall) and tt (dwarf) 
individuals in the progeny. Thus, a test cross can be used to determine the 
heterozygosity of the plant. 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
13.  
(a) BAC (bacterial artificial chromosomes) and YAC (yeast artificial chromosomes) 
are cloning vectors which are used in the Human Genome Project for cloning or 
amplification of human DNA fragments. 
 
(b) The total number of genes (coding for protein) in the human genome is 30,000, 
which is less than 2% of the total genome and almost 50% of the discovered 
genes have unknown functions. 
 
(c) SNP stands for Single Nucleotide Polymorphism. 
 
14.   
Homology Analogy 
Organs which have similar origin 
but different functions are called 
homologous organs. 
Organs which have the same 
function but are different in origin 
are called analogous organs. 
This condition is known as 
homology. 
This condition is known as 
analogy. 
Example: Wings of birds and 
forelimbs of humans 
Example: Wings of birds and wings 
of insects 
 
15.  
(a) People who have suffered from chickenpox in their childhood may not contract 
the disease again because of acquired immunity which is characterised by 
memory. 
 
Acquired immunity is pathogen-specific. At the incidence of the first encounter 
with the microbe, the body produces a primary response of low intensity. On 
subsequent encounters with the same pathogen, a secondary response occurs 
which is of high intensity. This is attributed to the fact that our body has memory 
of the pathogen from the first encounter which had resulted in the production of 
antibodies against the pathogen. 
 
(b) Interferons are proteins secreted by virus-infected animal cells. These 
interferons protect the non-infected cells from getting infected by inhibiting viral 
replication. 
 
  
Page 5


  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
CBSE 
Class XII Biology 
Board Paper 2016 – All India (Set 1)  
SOLUTION 
                                                                                                                           
SECTION A 
 
1. Male honey bees are born from unfertilised eggs, whereas female honey bees are 
born from fertilised eggs. Because the unfertilised egg carries half the number of 
chromosomes as compared to the fertilised egg, male honey bees have half the 
number of chromosomes as compared to female honey bees. 
 
2. In multiple ovulation embryo transfer (MOET), the genetic mother is administered 
with hormones which induce follicular maturation and superovulation. After 
fertilisation, the eggs are transferred to a surrogate mother at the 8 –32 cell stage for 
further development. The genetic mother can then be used for another round of 
superovulation. 
 
3. Biopiracy is the term given to unauthorised use of bioresources by multinational 
companies and other organisations without proper authorisation and compensatory 
payments to the people concerned. 
 
4. Two advantages of compressed natural gas (CNG) over diesel fuel: 
1. CNG burns more efficiently and very little residue is left unburnt. 
2. It is cheaper than diesel and chances of adulteration are negligible. 
 
5. Homo habilis did not eat meat, whereas Homo erectus was probably a meat eater.  
 
 
  
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
SECTION B 
 
6. Pea plant is a dioecious plant bearing bisexual flowers, i.e. the stamen and pistil are 
present on the same flower. Thus, the single pea plant can produce viable seeds 
after self-pollination. 
 
Papaya is a monoecious plant bearing unisexual flowers and requires cross-
pollination for viable seed production. Thus, a single papaya plant cannot produce 
viable seeds. 
 
7. Features of the genetic code: 
Stop codon: Signals termination of translation and does not code for any amino acid. 
Unambiguous codon: Each codon codes for only one amino acid. 
Degenerate codon: More than one codon can code for a specific amino acid. 
Universal codon: One codon codes for the same amino acid in all species. 
 
8. Important steps involved in conventional breeding technology: 
(i) Selection of parent plant with desired combination of characters 
(ii) Hybridisation of selected plants 
(iii) Selection and evaluation of hybrids 
(iv) Testing and release of new varieties for commercial production 
 
9. Nucleopolyhedrovirus is a genus of a baculovirus which are efficient biocontrol 
agents. They are considered good biocontrol agents because they are species-
specific and have no negative impacts on plants, mammals, birds, fish or even on 
non-target insects. 
 
10. The ozone layer is getting depleted by the action of chlorofluorocarbons (CFCs) 
used as a coolant in refrigerators and in perfumes. When CFCs are released into 
the stratosphere, they end up being broken up by ultraviolet light, resulting in 
chlorine being released. Chlorofluorocarbons bind to ozone, and the chemical 
reaction releases a chlorine free-radical capable of destroying thousands of 
molecules of ozone. 
OR 
            Sacred groves are forest fragments which are highly protected by certain 
communities because they are of religious importance to these communities. 
 
 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
SECTION C 
 
11.   
(a) The exine of the pollen grain is made of sporopollenin. Sporopollenin is one of 
the most resistant organic compounds. It can withstand high temperature, 
strong acids and alkalis and cannot be degraded by any of the known enzymes. 
Hence, it acts as a shield and protects the pollen grain from getting damaged. 
 
(b) Exine does not form a continuous layer around the pollen because it is absent in 
certain sections called germ pores which serve as an outlet for the formation of 
the pollen tube. 
 
(c) Pollen grains can be stored for years by cryopreservation. After this treatment, 
they are stored in pollen banks. Such conserved pollen grains can be used in 
plant breeding programmes. 
 
OR 
(a) Problems addressed through reproduction and child health care programmes: 
(i) Creating awareness among people about the various aspects related to 
reproduction. 
(ii) Providing facilities and support required for building and maintaining a 
reproductively healthy society. 
 
(b) Amniocentesis is a disorder test based on the chromosomal pattern in the 
amniotic fluid surrounding the developing embryo. It is used to detect any 
chromosomal defect in the embryo. However, recently, amniocentesis is being 
used to detect the gender of the foetus resulting in several female foeticides. This 
declines the gender ratio. Therefore, there is a statutory ban on amniocentesis to 
avoid female foeticides. 
 
12. Test cross is a cross between F 1 progeny and its homozygous recessive parent. 
This cross determines whether the dominant character is coming from 
homozygous dominant genotype or heterozygous genotype (e.g. tallness coming 
from TT or Tt). When TT is crossed with tt, we obtain all Tt (tall) individuals in the 
progeny, whereas when Tt is crossed with tt, we obtain Tt (tall) and tt (dwarf) 
individuals in the progeny. Thus, a test cross can be used to determine the 
heterozygosity of the plant. 
 
 
 
 
 
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
13.  
(a) BAC (bacterial artificial chromosomes) and YAC (yeast artificial chromosomes) 
are cloning vectors which are used in the Human Genome Project for cloning or 
amplification of human DNA fragments. 
 
(b) The total number of genes (coding for protein) in the human genome is 30,000, 
which is less than 2% of the total genome and almost 50% of the discovered 
genes have unknown functions. 
 
(c) SNP stands for Single Nucleotide Polymorphism. 
 
14.   
Homology Analogy 
Organs which have similar origin 
but different functions are called 
homologous organs. 
Organs which have the same 
function but are different in origin 
are called analogous organs. 
This condition is known as 
homology. 
This condition is known as 
analogy. 
Example: Wings of birds and 
forelimbs of humans 
Example: Wings of birds and wings 
of insects 
 
15.  
(a) People who have suffered from chickenpox in their childhood may not contract 
the disease again because of acquired immunity which is characterised by 
memory. 
 
Acquired immunity is pathogen-specific. At the incidence of the first encounter 
with the microbe, the body produces a primary response of low intensity. On 
subsequent encounters with the same pathogen, a secondary response occurs 
which is of high intensity. This is attributed to the fact that our body has memory 
of the pathogen from the first encounter which had resulted in the production of 
antibodies against the pathogen. 
 
(b) Interferons are proteins secreted by virus-infected animal cells. These 
interferons protect the non-infected cells from getting infected by inhibiting viral 
replication. 
 
  
  
 
CBSE XII  |  Biology 
Board Paper – 2016 – All India – Set 1 (Solution) 
 
     
16.  
(a) Two limitations of traditional breeding which led to the promotion of 
micropropagation: 
(i) It failed to fulfil the demand. 
(ii) It failed to provide an efficient and fast crop improvement system. 
 
(b) Two advantages of micropropagation: 
(i) Production of larger number of plants in very short duration of time 
(ii) Recovery of healthy plants from diseased plants 
 
(c) Micropropagation technology is adopted in the commercial production of many 
important food plants such as tomato and banana. 
      
17.  
(a) Organic farmers control pests by using natural predation instead of introduced 
chemicals. Microbial biocontrol agents are species-specific pesticides.  
(i) Example: Bacillus thuringiensis is a bacterium which produces a toxin 
which specifically kills insect larvae such as lepidopterans (armyworms), 
coleopterans (beetles) and dipterans (flies/mosquitoes), leaving aside all 
other non-targeted organisms. 
(ii) Another biocontrol agent is Trichoderma sp. which is a free-living fungus 
and works as a biocontrol agent against several plant pathogens. 
 
(b) As compared to conventional pest control methods, organic farmers  do not 
try to completely get rid of pests but keep them at manageable levels. They 
believe that complete eradication of pests is not beneficial and has certain 
adverse effects which lead to the death of those beneficial creatures which are 
dependent on them for food. 
 
18.  
(a) In the cloning vector pBR322, ampicillin and tetracycline resistance genes serve 
as selectable markers. They help in the selection of transformed cells from non-
transformed cells. They also help distinguish recombinant cells from non-
recombinant cells. 
 
(b) The gene for the enzyme ?-galactosidase is an alternative selectable marker. 
When the foreign gene is inserted within the ?-galactosidase gene, the enzyme ?-
galactosidase gets inactivated. Then the bacteria are grown on a chromogenic 
substrate. Non-recombinants will produce blue-coloured colonies, while 
recombinants will produce colourless colonies.