students must start practicing the questions from CBSE Sample Papers for Class 12 Biology with Solutions Set 10 are designed as per the revised syllabus.
CBSE Sample Papers for Class 12 Biology Set 10 for Practice
Time Allowed: 3 Hours
Maximum Marks: 70
General Instructions:
- All questions are compulsory.
- The question paper has five sections and 33 questions. All questions are compulsory.
- Section-A has 16 questions of 1 mark each: Section-B has 5 questions of 2 marks each; Section- C has 7 questions of 3 marks each; Section- D has 2 case-based questions of 4 marks each: and Section-E has 3 questions of 5 marks each.
- There is no overall choice. However, internat choices have been provided in some questions. A student has to attempt onty one of the alternatives ¡n such questions.
- Wherever necessary, neat and properly Labeled diagrams should be drawn.
Section – A (16 Marks)
Question 1.
The diagram shows LS of human testis.
Which of the following labeling is responsible for creation of male gametes namely spermatozoa?
(a) A
(b) B
(c) C
(d) D
Question 2.
DNA fragments result when cut
DNA molecules at specific sites.
(a) probes
(b) ligases
(c) polymerases
(d) restriction enzymes
Question 3.
Identify the relationship between Cuscuta and Cattle egret.
(a) Commensalism
(b) Amensalism
(c) Parasitism
(d) Predation
Question 4.
Which of the following is not a sexually transmitted disease?
(a) Gonorrhea
(b) Genital herpes
(c) Down’s syndrome
(d) Syphilis
Question 5.
Identify the correct sequence of DNA fingerprinting:
(a) Extraction → amplification → separation → southern blotting
(b) Amplification → extraction → southern blotting → separation
(c) Extraction → separation → southern blotting hybridization using VNTR probe
(d) Both (a) and (c)
Question 6.
Which transformation technique is represented in the above figure?
(a) Microinjection
(b) Electroporation
(c) Biolistics
(d) Particle bombardment
Question 7
test is prescribed for typhoid test.
(a) Widal
(b) ELISA
(c) CT
(d) MRI
Question 8.
Golden rice is:
(a) a kind of rice cultivated around China’s Yellow River.
(b) long-term storage of rice with a yellow hue.
(c) p-carotene-containing transgenic rice.
(d) a yellow-grained, wild kind of rice.
Question 9.
Tusharsaw an apparatus as shown below in the biotechnology lab during an experiment. The diagram below shows the setup of the process of gel electrophoresis. What will be the direction of flow of DNA fragments?
(a) Move towards the anode
(b) Move towards the cathode
(c) Do not move
(d) Move towards the negatively changed electrode
Question 10.
Match the organism with its use in biotechnology.
| A | B |
| (a) Bacillus thuringiensis | (i) Cloning vector |
| (b) Thermus aquatics | (ii) Construction of first rDNA molecule |
| (c) Agrobacterium tumefa- ciens | (iii) DNA polymerase |
| (d) Salmonella typhimurium | (iv) Cry proteins |
Select the correct option from the following:
(a) (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
(b) (A)-(ii), (B)-(i), (C)-(iii), (D)-(iv)
(c) (A)-(iv), (B)-(iii), (C)-(i), (D)-(ii)
(d) (A)-(ii), (B)-(iii), (C)-(iv), (D)-(i)
Question 11.
This is a floral part of Pap aver. Identify the parts (A) and (B).
| A | B |
| (a) Style | Syncarpous ovary |
| (b) Stigma | Syncarpous ovary |
| (c) Ovary | Style |
| (d) Apocarpous ovary | Stigma |
Question 12.
A multinational company outside India tried to sell new varieties of turmeric without proper patent rights. What is such an act referred to?
(a) Biopiracy
(b) IPR
(c) Biopatent
(d) Copyright
Question No. 13 to 16 consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true and R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is False but R is true.
Question 13.
Assertion (A): All the testicular lobules join together to form the laciferous duct.
Reason (R): Each testis has about about 250 compartments called testicular lobules.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true and R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is False but R is true.
Question 14.
Assertion (A): Genes encoding antibiotic resistance are essential for facilitating cloning into a vector.
Reason (R): The vector requires a selectable marker, which helps in identifying and eliminating non¬transformants.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true and R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is False but R is true.
Question 15.
One of the most well-known instances of cross-pollination is Vallisneria. Its dioecious flowers are cleverly arranged at the water’s surface and it lives vegetatively as a submerged aquatic.
Assertion (A): Pollen grains produced by of Vallisneria are long and needle-like.
Reason (R): Pollens are carried passively by water.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true and R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is False but R is true.
Question 16.
Assertion (A): Some species of frog use poison against their predators and their prey.
Reason (R): Most frogs employ camouflage against prey and predators.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true and R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is False but R is true.
Section – B (10 Marks)
Question 17.
Give two examples each of the following:
(A) Vestigial organs
(B) Atavism
Question 18.
Pests are controlled by natural enemies without the need for human intervention through natural biological control, an ecosystem service. In contrast to agricultural systems, this may be the case in unmanaged natural systems like tropical forests. Why baculovirus considered as good biocontrol agents? Name a genus of baculovirus.
Question 19.
In the picture shown below, shape (P) and shape (Q) indicate other forms of the peptide hormone secreted by the mammalian pancreas.
(A) What type of bond is present between hormonal chains?
(B) What are the shape (P) and shape (Q)? How these shapes are different from each other?
Question 20.
Define:
(A) Ontogeny
(B) Phylogeny
(C) Acclimatization
(D) Gene pool
OR
(A) Rearrange the genera in the sequence starting from the youngest:
Ramapithecus, homo erectus, homo sapiens, homo habilis, Australopithecus
(B) Name the common ancestor of apes and man.
Question 21.
Study the section of the malarial parasite’s life cycle that is provided below. Answer the following questions.
(A) Describe X’s function in the malarial parasite’s life cycle.
(B) Identify event Z and the organ in which it takes place.
Section – C (21 Marks)
Question 22.
State the basic principle behind in-situ and the ex-situ conservation. Which three biodiversity hotspots cover our country’s high biodiversity regions?
Question 23.
(A) Identify the above technique.
(B) Define the technique mentioned above.
(C) Describe the importance of the above technique.
Question 24.
During a monohybrid cross involving a tall pea plant with a dwarf pea plant, the off springs were tall and dwarf in equal ratio. Work out on a cross to show how it is possible.
Question 25.
Give reasons:
(A) Satellite DNA is significant in DNA fingerprinting.
(B) Splicing is an important process in transcription.
OR
Consider the template strand given below: A TGCATGCATAC
(A) Construct a complete transcription unit with promoter and terminator based on the template given.
(B) Write the sequence of RNA that will be transcribed from the above transcription unit along with its polarity.
Question 26.
A victim of road accident was brought to a nursing home. The first thing that the doctor did was to give him an injection.
(A) What did the doctor inject into the patient’s body?
(B) Name the disease against which this injection was given and the kind immunity it provides.
(C) How would this injection protect the patient against a deadly disease?
Question 27.
Identify (A) and (B) in the given diagram. Write one function for each.
Question 28.
(A) Explain why bottled fruit juices are clearer as compared to those made at home.
(B) Write the medicinal value and the bioactive molecules produced by Monascus and Trichoderma.
Section – D (8 Marks)
(Q. No. 29 and 30 are case based questions. Each question has subparts with internal choice in one subpart.)
Question 29.
Charaka was studying the steps that are a requisite in the formation of a recombinant DNA. He came across the actions of restriction enzymes. There are some questions in his mind regarding the same. Can you help Charaka in solving them out?
(A) What type of nucleotide sequence are recognized by each restriction endonuclease?
(B) Where do restriction enzymes cut the strand of DNA?
(C) What is the advantage of formation of sticky ends by the action of restriction endonucleases?
OR
Exonucleases remove nucleotides from the ends of the DNA. Justify the statement.
Question 30.
DNA has a double-helical structure. The two polynucleotide chains have antiparallel polarity. There are two types of Nitrogenous bases- Purines and Pyrimidines. Adenine and Guanine are the Purines and the rest are Pyrimidines. Erwin Chargaff stated that DNA molecules have an equal ratio of Purines and Pyrimidines.
Two nucleotides are linked through a 3’→5′ Phosphodiester linkage.
Many of them, when linked together, form a polynucleotide. The bases in the two opposite strands are paired with hydrogen bonds with a purine always coming opposite to a pyrimidine. The pitch of the helix is 3.4 nanometre, with approximately 10 base pairs in each turn. The distance between a base pair in a helix is thus 0.34 nm (approx.). We just divided the pitch with the number of base pairs in each turn to get the distance between a base pair.
(A) Which among these is not a component of a nucleotide?
Nitrogenous base, Pentose sugar, Phosphate group, Ketone group.
(B) DNA sequence of a single strand is:
3 AGTCAGTCAGTCAGTCAGTC- 5 ’
What will be the complementary strand in 3’-5’ direction?
(C) dsDNA has 30% Thymine. What will be the percentage of Guanine in the DNA?
OR
Based on the above graph, if the percentage of Adenine is 30%, what will be the percentage of Cytosine?
Section – E (15 Marks)
Question 31.
(A) Draw a diagram of an enlarged view of T.S. of microsporangium of an angiosperm and label the following:
(i) The three wall layers
(ii) Microspore mother cells
(B) Mention the characteristic features and function of the layers labelled in (A).
(C) Give reasons:
(i) Pollen grains are well preserved as fossils.
(ii) Nowadays people use pollen tablets.
OR
(A) Why is the process of fertilisation in angiosperms termed as double fertilisation?
The graph is showing the number of patients suffering from respiratory illnesses. On the basis of this graph, answer:
(i) Which area might have more individuals of Parthenium and why?
(ii) What are pollen supplements?
Question 32.
Study the diagram given below and answer the questions that follow:
(A) Name the process happening in the above diagram. Describe its initiation phase.
(B) In which phase of the cell cycle does replication occur in eukaryotes? What would happen if cell division is not followed after DNA replication?
OR
Answer the following:
(A) Identify the above structure.
(B) Explain the packaging that is involved in order to get this structuralformation.
(C) Name the repeating structures in a nucleosome. followed after DNA replication?
(D) Expand and describe NHC.
Question 33.
Sushmita is planning to write a research paper on the importance of conserving biodiversity. Help her in formulating any new hypothesis or an example given by any previous biologist on the aforementioned topic.
OR
(A) Mention the approaches to conserve biodiversity.
(B) Describe the biodiversity at different level of scales.
(C) There are a total of 10 species that are unique between two ecosystems. Ecosystem X may have 8 unique species which are not seen in ecosystem Y, while ecosystem Y has 2 unique species that are not seen in ecosystem X. identify the beta diversity between the two ecosystems.