students must start practicing the questions from CBSE Sample Papers for Class 12 Biology with Solutions Set 9 are designed as per the revised syllabus.
CBSE Sample Papers for Class 12 Biology Set 9 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 part of the flower which is represented by tassels of the corn-cob is:
(a) Style and stigma
(b) Stigma and peduncle
(c) Thalamus
(d) Peduncle
Question 2
is the term used for the transcriptionally active region of chromatin in a nucleus?
(a) Heterochromatin
(b) Euchromatin
(c) Chromatin
(d) Histones
Question 3.
For some bacterial infections, antibiotics might not be necessary. For many sinus infections or some ear infections, for instance, you might not need them. Antibiotics have side effects and won’t help you if you take them when you don’t need them. The best course of treatment for you when you are ill can be decided by your healthcare provider. Identify source organism from which the first antibiotic was produced.
(a) Penicillium notatum
(b) Rhizobium
(c) Frankia
(d) NucLeopolyhedrovirus
Question 4.
Other names for Sexually Transmitted Diseases are:
(a) Veneral diseases
(b) Reproductive tract infections
(c) Both (a) and (b)
(d) Communicable disease
Question 5.
What will be the polarity of this strand?
(a) Parallel | 3′ → S’ |
(b) Antiparallel | 3′ → 5′ |
(c) Parallel | 5′ → 3′ |
(d) Antiparallel | 5′ → 3′ |
Question 6.
Observe the ladder of human evolution.
Which of the following reflects about the man tike primate, that existed 15 mya, fossils found in Tanzania?
(a) Homo erectus
(b) Australopithecus
(c) Ramapithecus
(d) Homo sapiens neanderthalensis.
Question 7.
Which of the following fungus is used in alcohol industries?
(a) Penicillium
(b) Mucor
(c) Rhizcpus
(d) Yeast
Question 8.
Identify the incorrect match:
Type of barrier | Barrier |
(a) Physiological | Lysozyme |
(b) Cellular | WBC |
(c) Anti-viral substance | Sero-mucous surface |
(d) Physical | Skin |
Question 9.
Match the trophic levels with their correct species examples in grassland ecosystem.
Column-I | Column-II |
Fourth trophic level | (i) Crow |
Second trophic level | (ii) Vulture |
First trophic level | (iii) Rabbit |
Third trophic level | (iv) Grass |
(a) (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
(b) (A)-(ii), (B)-(i), (C)-(iii), (D)-(iv)
(c) (A)-(i), (B)-(ii), (C)-(iii), (D)-(iv)
(d) (A)-(ii), (B)-(iii), (C)-(iv), (D)-(i)
Question 10.
Determine the right sequence of the Palaeozoic era’s on the geological time scale.
(a) Cambrian → Devonian – Ordovician → Silurian → Carboniferous → Permian
(b) Cambrian → Ordovician → Silurian Devonian → Carboniferous → Permian
(c) Cambrian → Ordovician → Devonian → Silurian → Carboniferous → Permian
(d) Silurian → Devonian → Cambrian → Ordovician → Permian → Carboniferous
Question 11.
Biopatent is the:
(a) legal property offered by the state to an inventor.
(b) rights which are given to the creator for use.
(c) prevention of large-scale loss of biological integrity.
(d) statuary rights granted by the government to the creators.
Question 12.
Identify the odd one out:
(I) Rudimentary wings in ostrich
(II) Tendrils of Pisum
(III) Wings of insects and bats
(IV) Flippers of Penguins and Dolphins Select the correct option:
(a) (I)
(b) (II)
(c) (HI)
(d) (IV)
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 of the direct evidence of the beginning of life has been lost.
Reason (R): The individuals in charge of safeguarding evidence lacked expertise.
(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.
The two most populous nations in the world, China and India, with more than 1.4 billion inhabitants each, will experience rapid demographic change over the next few decades, which will jeopardise their hard- won economic advancement.
Assertion (A): India’s population is set to overtake China’s population by 2025.
Reason (R): The birth rate in China is decreasing while it is increasing in India.
(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.
Assertion (A): E.coLi with pBR.322 with DNA insert at Bam HI site cannot grow in medium containing tetracycline.
Reason (R): Recognition site for Bam H1 is present in tet-R region of pBR322.
(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): Bacillus thuringiensis can form protein crystals that contain a toxic insecticidal protein.
Reason (R): RNA interference is a novel strategy against nematode infestation.
(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.
Why is the structure (i) located outside the abdominal cavity?
Name the pouch In which they are present.
OR
(A) A newborn Is fed with coLostrum which provides immunity. Name the type of Immunity produced by it.
(B) Where do we find fimbriae?
Question 18.
(A) Identify ‘a ‘b,c’ and ‘d’in the diagram below.
(B) Mention the factors affecting spermatogenesis.
Question 19.
Crop and animal biotechnology have advanced thanks to recombinant DNA (rDNA) technology. The power of rDNA technology stems from our ability to manipulate genes and introduce them into plant and animal cells in order to study and alter gene function. With the help of a flowchart explain the formation of recombinant DNA by the action of restriction endonuclease EcoRI.
Question 20.
(A) Name any two copper-releasing IUDs.
(B) How do IUDs act as effective
contraceptives in human females?
Question 21.
What type of sex-determination mechanisms are shown by the following crosses? Give example of each.
(A) Female XX with Male XY
(B) Female ZW with Male ZZ
Section – C (21 Marks)
Question 22.
Why anthers in Angiosperms are called as dithecous? Describe the structure of its microsporangium with the help of diagram.
Question 23.
Observe the graph and answer the questions that follow:
(A) Which vector is most suitable to link the alien DNA? State your reasons.
(B) What is a stirred tank bioreactor? What purpose does it serve? Name the components of this bioreactor.
Question 24.
Yajur was studying animal relationships and interactions. He came across a few associations on internet. Help him guess the type of interaction seen in each of the following examples:
(A) Ascaris worms living in the intestine of human.
(B) Mycorrhizae
(C) Weeds and pests
Question 25.
Identify (A), (B), (C), (D), (E), and (F) in the table given below:
scientific name of the organism | Product produced | Use in human welfare |
Strepto coccus | Streptokinase that was later modified | (A) |
(B) | Cyclosporin A | (C) |
Monascus purpureus | (D) | (E) |
Yeast | (F) | Invert sugar for ice creams |
OR
Study the diagram of an antibody given below and answer the questions that follow.
(A) Identify (i), (ii), and (iii) in the diagram.
(B) Why is an antibody molecule referred to as H2L2?
(C) Which antibody is present in colostrum?
Question 26.
Give reasons:
(A) Consumption of contaminated food and water can result in dysentery.
(B) Mosquito bites can also result in Elephantiasis.
Question 27.
Given above is the schematic representation of lac operon in Exoli.
(A) Name the inducer and its role in the above operon.
(B) Looking at the above diagram, tell how many enzymes are required for the breakdown of lactose in E.coli? Which among the genes shown, code for the proteins needed by the cell for structural functions or synthesis of the aforementioned enzymes?
Question 28.
(A) Differentiate between benign and malignant tumors.
(B) Name the causative agents of elephantiasis and mention its symptoms.
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.
U | C | A | G | ||
U | UUC Phe
UUC Phe UUA Leu UUG Leu |
UCU Ser
UCC Ser UCA Ser UCG Se |
UAU Tyr
UAC Tyr UAA Stop UAG Stop |
UGU Cys
UGC Cys UGA Stop UGG Trp |
U
C A G |
C | CUU Leu
CUC Leu CUA Leu CUG Leu |
CCU Pro
CCC Pro CCA Pro CCG Pro |
CAU His
CAC His CAA Gin CAG Gin |
CGU Arg
CGC Arg GCA Arg CGG Arg |
U
C A G |
A | AUU Ile
AUC Ile AUA Ile AUG Met |
ACU Thr
ACC Thr ACA Thr ACG Thr |
AAU Asn
AAC Asn AAA Lys AAG Lys |
AGU Ser
AGC Ser AGA Arg AGG Arg |
U
C A G |
G | GUU Val
GUC Val GUA Val GUG Val |
GCU Ala
GCC Ala GCA Ala GCG Ala |
GUA Asp
GAC Asp GAA Glu GAG Glu |
GGU Gly
GGC Gly GGA Gly GGG Gly |
U
C A G |
The figure Lists the codons for various amino acids. There are a total of 61 codons which code for amino acids. The code is universal for all organisms. On the basis of the above table, answer the following questions:
(A) Is codon specific?
(B) Using the above checkerboard, predict the amino acid sequence coded by the following mRNA:
GUG UCU UCC UCU UCC UCU GGA GGG
(C) ’What is the nature of a codon?
OR
Which among these are the stop codons? Use the checkerboard.
Question 30.
This is an E.coli cloning vector pBR.322. It is showing several sites meant for different purposes. Based on your previous knowledge and inferences from the graph, answer the following questions:
(A) Replication will start from which sequence?
(B) Name any two selectable markers
Observe the graph given above and tell which one is the most suitable vector.
OR
A recombinant DNA molecule was produced by joining a gene to a plasmid vector. Exonuclease enzyme is accidentally added to the tube holding the recombinant DNA by one of your classmates. How will the transformation you propose to make today effect your experiment?
Section – E (15 Marks)
Question 31.
Explain the process of fertilisation and implantation in humans.
OR
(A) L.S. of an is shown below:
Label any six parts:
(B) Give reason for each of the following:
(i) Apple and cashew are not called true fruits.
(ii) Hybrid seeds have to be produced year after year.
Question 32.
Shantanu was going through the medical reports of a person suffering from Phenylketonuria. He couldn’t find out the reason behind its pleiotropic origin. Explain why it is a pleiotropic disease and also write the cause and symptoms of the disease.
OR
How do rRNA, t-RNA and ribosomes help in the process of translation?
Question 33.
The graph given shows the number of animals spotted in a particular region at different time periods.
(A) What could have been the reason behind the drastic reduction in animal spotting between October-January? What can you say about the general climatic condition of the region in question?
(B) Which place is famous in Rajasthan for witnessing massive arrival of birds from Siberian regions in harsh climatic conditions?
(C) What do you understand by the term ‘Homeostasis’?
(D) What are conformers?
OR
Explain why:
(A) Small animals are rarely found in Polar regions.
(B) Mammals from colder climates have short ears and limbs.
(C) Desert plants have a CAM pathway.
(D) Calotropis produces Cardiac glycosides.