Students can access the CBSE Sample Papers for Class 12 Biology with Solutions and marking scheme Term 2 Set 10 will help students in understanding the difficulty level of the exam.
CBSE Sample Papers for Class 12 Biology Standard Term 2 Set 10 for Practice
Time Allowed: 2 Hours
Maximum Marks: 40
- All questions are compulsory.
- The question paper has three sections and 13 questions. All questions are compulsory.
- Section-A has 6 questions of 2 marks each; Section-B has 6 questions of 3 marks each, and Section-C has a case-based question of 5 marks.
- There is no overall choice. However, internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions.
- Wherever necessary, neat and properly labeled diagrams should be drawn.
SECTION – A
(Section A has 6 Questions of 2 marks each.)
Certain features are required to make a stable biological, community. List any two.
List any two advantages of the IUCN Red List. (2)
(A) Mention the role of cyanobacteria in the paddy field that is beneficiaL for the rice crop.
(B) Who worked on the chemotherapeutic effectiveness of penicillin? (2)
Our body has different types of barriers as a part of innate immunity that prevents the entry of foreign agents. Name the type of barrier of Innate immunity, which involves:
(B) Hcl of stomach (2)
The given picture shows the surface of the cultural, medium in a fermenter, which is having white foam Like substance known as flocs. (2)
(A) What is meant by flocs?
(B) What is a fermenter or bioreactor?
Name the organisms shown in the given picture and what kind of relationship they share? Describe briefly.
State Gause’s ‘Competitive Exclusion Principe’. (2)
(A) Suman was confused to observe that the fruit juices that we prepare at home are not clear whereas bottled fruit juices appear cLearer. Give reason for this.
(B) How statins help in Lowering the bLood cholesterol Level? (2)
SECTION – B
(Section B has 6 Questions of 3 marks each.)
List any three factors by which the health of an individual is affected. (3)
Represent diagrammatically the technique of recombinant DNA technology. (3)
The given picture shows one of the symptoms of a fungal disease that is caused by Microsporum. Name the disease and also write its mode of transmission and symptoms. (3)
(A) Reema was conducting an experiment using a PCR machine. By mistake, she missed the PCR denaturation step and as a result, could not achieve the goals of her experiment. Elaborate the reason.
(B) After the process of gel electrophoresis, the DNA needs to be extracted. By which process this is done?
Give three points of difference between plasmid DNA and chromosomal DNA. (3)
In a pond there were 30 water hyacinth plants. 10 new water hyacinth plants were added in a year through the process of reproduction. Calculate the birth rate of the population and also define birth rate. (3)
Threatened species are the species which are vulnerable to endangerment in the near future. But these species can be saved by using different techniques to protect their gametes. Describe any three methods used for protection of gametes of threatened species. (3)
SECTION – C
(Section C has a case-based question of 5 marks.)
The given picture depicts the effect of an insect-resistant plant on the pests. It shows how insecticidal proteins are produced by the plants that specifically kill the insect larva and thus save the plant from infection. Based on this answer the following questions:
(i) Which organism is responsible for the production of an insect-resistant transgenic cotton by inserting a piece of DNA?
(ii) What is the trigger for activation of toxin of Bacillus thuringiensis inside insect?
(iii) What are Cry genes? In which organism are they found?
(B) Bt tobacco was first cultured to kill which worm.
(i) Human lymphocytes
(ii) Plant cells
The following picture shows a tobacco plant infected with a nematode. Answer the questions that follow: (5)
(A) Which part of tobacco plant is infected by Meloidogyne incognita?
(B) Which vector is popularly used to transfer nematode-specific genes into the tobacco plants?
(C) How are tobacco plants benefited when nematode-specific genes are introduced into them using certain vectors? Name the vector used.
(D) What is the role of Agrobacterium in the production of dsRNA in tobacco plant?