QUESTION PAPER
2022 BOARD EXAM
CBSE CLASS 12-PCB BIOLOGY Board Paper 2022 — Set 1
2022
BIOLOGY
CLASS 12-PCB
CBSE EXAMINATION PAPER-2022
BIOLOGY
(Solved)
General Instructions :
Read the following instructions carefully and follow them :
- This question paper contains 29 questions. All questions are compulsory.
- This question paper is divided into 5 sections.
- Section A – questions number 1 to 1 are case based questions
- Section B – questions number 2 to 11 are multiple choice questions
- Section C – questions number 12 to 18 are very short answer
- Section D – questions number 19 to 25 are short answer
- Section E – questions number 26 to 29 are long answer
- There is no overall choice given in the question paper. However, an internal choice has been provided in few questions.
- Use of calculator is NOT allowed.
Section A
Section B
The primary source of energy for Earth's climate system is:
Which of the following statements is true about genes?
The process by which organisms maintain a stable internal environment is called:
What is the main function of the ribosome?
Which of the following structures is involved in photosynthesis?
Which molecule is known as the energy currency of the cell?
Which of the following is the start codon for protein synthesis?
In the Meselson and Stahl experiment, the DNA extracted after one generation of replication in ¹⁵N medium showed:
Bt-cotton is resistant to:
Which of the following is a vector used to transfer genes into plant cells?
Section C
Mention the parts of human body that get affected by Pneumonia and common cold infections. Write the causative agents of the two diseases.
State the impact of constant mechanical agitation and pumping of air in the aeration tank on the sewage during the biological treatment.
(a) Give an example of viral biocontrol agent.
(b) Why are they considered to be desirable when an ecologically sensitive area is being treated?
What is the importance of female Anopheles mosquitoes m the life of a malarial Parasite Plasmodium ?
Study the graph given below, showing the population growth curves 'A' and 'B' respectively. Answer the following questions:
(a) What is 'Carrying Capacity' in respect of Curve 'B' indicative of?
(b) Mention the action of possible natural forces that could have lead to curve 'B'.
The histogram given below representing the data for annual shark harvest in the great barrier reef I coral reef located on the east coast of Queensland, Australia. Study the histogram and answer the questions that follow.
(a) Write your interpretation of the data given.
(b) Write the impact on the biodiversity of the area that you can interpret on the basis of given data.
(i) cattle excreta is important source for producing a domestic fuel . Name the fuel and write its main components.
(ii) Write the biological process that responsible for the production of this fuel.
Section D
The data collected based on the survey conducted for species richness of group of mammals, in three different climatic regions of the world is shown in the bar graph given below.
Panama has nearly 560 species of mammals, Canada has nearly 301 species of mammals and Denmark has 67 species of mammals.
(i) Based on the species, richness, identify the location of these countries in the respective climatic regions given.
(ii) Plantsand animalsdonothaveauniformdiversityintheworld.Write the term given to this pattern of diversity and why?
Bio-diversification of life started to occur almost 3 billion years ago. Since then new species have been evolving and then disappearing en masse from earth.
(a) How many episodes of mass extinctions of species have already taken place and which one is in progress in the current era?
(b) How is current episode in progress different from the previous episodes and why ? Explain.
Name two naturally occurring sources, one that transfers pathogenic genes into a plant cells and the other into an animal cell respectively, for their benefit. Write how have these naturally occurring sources been used for the benefit of human race by the biotechnologists.
Enumerate the main sources of bio-fertilisers giving one example of each.
Explain giving reason the action plan followed by organic farmers that support their key belief "biodiversity furthers health of crop lands".
(i) State the role of a selectable marker in r-DNA technology.
(ii) Name one such selectable marker which is considered to be useful for E.coli.
(iii)Give one reason why is it considered to be a useful marker.
What are plasminds ? How they different from cloning vectors ? give one example each for a viral and bacterial cloning vector ?
Section E
Explain the process of DNA replication in eukaryotes. Why is it called semiconservative?
Describe the structure of a human male reproductive system.
Explain Mendel's laws of inheritance with suitable examples.
Describe the steps involved in recombinant DNA technology.
Other Years — BIOLOGY