CBSE Sample Papers for Class 12 Biology Set 5 with Solutions

Practicing the CBSE Sample Papers for Class 12 Biology with Solutions Set 5 allows you to get rid of exam fear and be confident to appear for the exam.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions

Time: 3 Hours.
Max. Marks: 70

General Instructions:

  1. All questions are compulsory.
  2. The question paper has five sections and 33 questions. All questions are compulsory.
  3. 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 A marks each; and Section- E has 3 questions of 5 marks each.
  4. 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.
  5. Wherever necessary, neat and properly labeled diagrams should be drawn.

Section – A (16 Marks)

Question 1.
The red data book contains data of:
(a) All plant species
(b) All animal species
(c) Economically important species
(d) Threatened species
Answer:
(d) Threatened species

Explanation: The Red Data Book is a type of public document, which is created for the recordings of rare and endangered species or threatened including animals, plants, and fungi as well as some local subspecies, which are present within the region of the state or the country.

Question 2.
Western Ghats have a greater number of amphibian species than Eastern Ghats. What kind of diversity does it represent?
(a) Species diversity
(b) Genetic diversity
(c) Ecological diversity
(d) None of these
Answer:
(a) Species diversity

Explanation: Species diversity is the variety in the number and richness of the species of a region, Western Ghats have greater amphibian species diversity as compared to eastern ghats.

Question 3.
Which of the following statements is not supported by this graph?
C:\Users\Madura\Pictures\CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 3.png

Figure: This chart shows the percentage of various animal species, by group, on the IUCN Red List as of 2007. ’
(a) There are more vulnerable fishes than critically endangered and endangered fishes combined.
(b) There are more critically endangered amphibians than vulnerable, endangered and critically endangered reptiles combined.
(c) Within each group, there are more critically endangered species than vulnerable species.
(d) A greater percentage of bird species are critically endangered than molluscs species.
Answer:
(c) Within each group, there are more critically endangered species than vulnerable species.

Explanation: Species richness is defined as the number of species represented in a specific region, I landscape or an ecological community.

Question 4.
One of the most resistant biological material is:
(a) Lignin
(b) Cutin
(c) Sporopollenin
(d) Cellulose
Answer:
(c) Sporopollenin

Explanation: Outer layer (exine) of pollen grain is made of a highly resistant substance called sporopollenin. Sporopollenin is not degraded by any enzyme because of sporopollenin, pollen grains are well preserved as fossils.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions

Question 5.
Prostate gland is present:
(a) On ureter
(b) On kidney
(c) On testis
(d) Around urethra
Answer:
(d) Around urethra

Explanation: The prostate is located just below the bladder and in front of the rectum. It is about the size of a walnut and surrounds the urethra. The primary function of the prostate is to produce the fluid that nourishes and transports sperm (seminal fluid).

Question 6.
When yeast ferments glucose, the products formed are:
(a) Ethanol and Water
(b) Water and Carbon dioxide
(c) Ethanol and Carbon dioxide
(d) Methanol and Water.
Answer:
(c) Ethanol and Carbon dioxide.

Explanation: Glucose \(\stackrel{\text { yeast }}{\longrightarrow}\) Ethanol + Carbon dioxide

C6H12o6(aq) \(\stackrel{\text { yeast }}{\longrightarrow}\)2C2H5(aq) +2C02(aq)

Question 7.
Name the drug used’in cancer treatment produced by using biotechnology:
(a) Tenamycin
(b) HGH
(c) TSH
(d) Interferon
Answer:
(d) Interferon

Explanation: Interferons are a family of naturally-occurring proteins that are made and secreted by cells of the immune system. Interferons can promote or hinder the ability of some cells to differentiate.

Question 8.
Minisatellites are:
(a) 10-40 bp sized short sequences within the genes
(b) Short coding repetitive regions on the eukaryotic genome
(c) Short non-coding repetitive sequences present throughout the chromosome
(d) Are regions of chromosomes after secondary constriction
Answer:
(c) Short Non-coding repetitive sequences present throughout the chromosome

Explanation: Minisatellite-manynumerous repetitive non-codingDNAsegments thatare prominent in centromere and telomere regions.

Question 9.
DNA fingerprinting works because:
(a) Most genes are dominant
(b) All organisms contain RNA
(c) The most important genes are different among most people
(d) No two people, except identical twins, have exactly the same DNA
Answer:
(d) No two people, except identical twins, have exactly the same DNA

Explanation: DNA fingerprinting works because no two people, except identical twins, have exactly the same DNA.

Question 10.
The following statements are drawn as conclusions from the graph given below:

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 10

I. White women and black women have the highest incidence (rate of new breast cancer cases) overall.
II. American Indian and Alaska Native women have the lowest incidence.
III. Asian Women have highest incidence.
IV. Hispanic women have lowest incidence.
Choose the correct alternative from below:
(a) Both I and II are correct
(b) All are true
(c) Only III is correct
(d) Only I is correct
Answer:
(a) Both I and II are correct

Explanation: White women and black women have the highest incidence overall and American Indian and Alaska Native women have the lowest incidence rate because of the climatic conditions and the nutrition habits which impacts the immunity level of the women and thus results in different rates of incidence as well.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions

Question 11.
The Ti plasmid used in genetic engineering is obtained from:
(a) Bacillus thruingiensis
(b) E.Coli
(c) Agrobacterium hizogenes
(d) Agrobacterium tumefaciens
Answer:
(d) Agrobacterium tumefaciens

Explanation: Ti plasmid used in genetic engineering of plants is obtained from the bacterium Agrobacterium tumefaciens that causes crown gall disease in plants

Question 12.
The diversity of organisms sharing the same habitat or community is termed as:
(a) Alpha diversity
(b) Beta diversity
(c) Gamma diversity
(d) Delta diversity
Answer:
(a) Alpha diversity

Explanation: The terms alpha, beta and gamma diversity were all introduced by R. H. Whittaker to describe the spatial component of biodiversity. Alpha diversity is the mean species diversity in sites or habitats at a more local scale sharing the same community habitat. Beta diversity is defined as the ratio between regional and local diversity. Gamma diversity is the diversity in the entire species pool of a particular region

Questions 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): Gynoecium consists of pistil.
Reason (R): It represents the male reproductive part in flowering plants.
Answer:
(c) A is true but R is false.

Explanation: The gynoecium represents the female reproductive part of the flower consisting of pistil. Thus, assertion is true but reason is false

Question 14.
Assertion (A): Megaspore mother cell undergoes meiosis to produce four megaspores.
Reason (R): Megaspore mother cell and megaspore both are haploid.
Answer:
(c) A is true but R is false.

Explanation: Diploid megaspore mother cell is developed inside the nucellus. It then undergoes meiotic division to form four haploid megaspores. Thus, the assertion is true but reason is false.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions

Question 15.
Assertion (A): Mendel conducted cross pollination experiments on true-breeding lines.
Reason (R): True-breed lines have stable trait inheritance for several generations.
Answer:
(b) Both A and R are true and R is not the correct explanation of A.

Explanation: Mendel carried out hybridisation experiments on garden pea for many years. He performed various types of cross breeding and then allowed the offspring to self breed. All selected varieties used by him were pure lines of true breeding lines i.e., they produce offspring resembling the parents. These lines show the stable trait inheritance and expression for several generations making them suitable for genetic studies. Thus, both assertion and reason are true and reason is not the correct explanation of assertion.

Question 16.
Genetically modified organisms (GMOs) refers to organisms (i.e., plants, animals or microorganisms) in which the genetic material (DNA) has been manipulated in a way that does not occur naturally by mating and/or natural recombination. The technology is often called “modern biotechnology” or “gene technology”, sometimes also “recombinant DNA technology” or “genetic engineering”. It allows selected individual genes to be transferred from one organism into another, also between non-related species.

Foods produced from or using GM organisms are often referred to as GM foods. Generally consumers consider thatconventional foods are safe. Whenever novel varieties of organisms for food use are developed using the traditional breeding methods that had existed before the introduction of gene technology, some of the characteristics of organisms may be altered, either in a positive or a negative way.

National food authorities may be called upon to examine the safety of such conventional foods obtained from novel varieties of organisms, but this is not always the case.
Assertion (A): A crop expressing a cry gene is usually resistant to a group of insects.
Reason (R): Cry proteins produced from Bacillus thuringiensis are toxic to larvae of certain insects.
Answer:
(d) A is false but R is true

Explanation: In nomenclature ofrestriction enzymes, the first letter of the name of the genus in which given enzyme is discovered is written first in capital. It is followed by the first two letters of species name of the organism and these three letters are generally written in italics. Hin and Hpa, both are prcjduced from a single genus Haemophilus but from two different species i.e,, H. influenzae and H. parainfluenza respectively. Thus, assertion is false but reason is true.

Section – B (10 Marks)

Question 17.
Besides better aeration and mixing properties, what other advantages do stirred tank bioreactors have over shake flasks?
Answer:
Some of the other advantages that the stirred tank bioreactors have over shake flasks are:
1. Small volumes of culture can be taken out from the reactor for sampling or testing.
2. It has a foam breaker for regulating the foam.
3. It has a control system that regulates the temperature and pH

Question 18.
Analyse the graphical representation and answer the questions based upon it :

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 18

(a) Identify B and C.
(b) Identify D and E.
(b) D and E are pituitary hormones namely FSH and LH respectively.
Answer:
(a) B and C are ovarian hormones namely Estrogen and Progesterone respectively.
Question 19.
Based on the Pedigree traits, analyse the symbols used in human pedigree and say what they denote:

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 19

Answer:
(i) This sign denotes a healthy unaffected male.
(ii) This sign denotes a diseased affected male.
(iii) This sign denotes the mating of disease affected female with healthy unaffected male.
(iv) This sign denotes the consanguineous mating in which both male as well as female are disease affected

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions

Question 20.
How are tobacco plants benefited when nematode-specific genes are introduced into them using certain vectors? Name the vectors used.
Answer:
It is done by using the Agrobacterium vectors, the nematode specific genes are introduced into the host plant. The introduction of DNA initiates RNA interference and thus, silences the specific mRNA of nematode Meloidegyne incognita. As a result the parasite cannot survive in the body of the host.

Question 21.
What is the cloning of DNA?
OR
Why does the insecticidal protein produced by Bacillus thuringiensis not kill the bacterium, but kill the cotton bollworm? Explain.
Answer:
It is the process of replication and multiplication of alien DNA into the host organism, where alien DNA gets linked with the origin of replication.

OR

The Bt toxin protein exists as inactive prototoxin. The Bt toxin dissolves in the insect gut a which is alkaline in nature and becomes active. The toxins then attack the gut cells of the insect, punching holes in the lining. The Bt spores spill out of the gut and germinate in the insect causing death. Therefore, it does not kill the bacteria. Since the bacteria does not provide alkaline nature to convert the inactive protein to its active form

Section – C (21 Marks)

Question 22.
The following figure shows lac operon, explain the following questions on lac operon.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 22

(a) Who described the phenomenon of lac operon?
(b) What does lac denote in lac operon?
(c) In which organism lac operon takes place?
Answer:
(a) Francois Jacob and Jacques Monod described the phenomenon of lac operon.
(b) Lac denotes lactose in lac operon.
(c) Lac operon takes place in £. coli.

Question 23.
Answer the following questions:
(a) What is “population” according to you as a biology student?
(b) “The size of a population for any species is not a static parameter. “Justify the statement with specific reference to fluctuation in the population density of a region in a given period of time.
Answer:
(a) Population is the total number of organisms of a species in a particular area at a particular time.
(b) The size of a population for any species is not a static parameter because of factors like:

1. Birth Rate or Natality: Number of births during a given period.

2. Death Rate or Mortality: Number of deaths during a given period.

3. Immigration: Number of individuals of the same species that have come into the habitat from elsewhere during the time period under consideration.

4. Emigration: Number of individuals of the population who left the habitat and gone elsewhere
during the time period under consideration.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions

Question 24.
Explain the role of DNA dependent RNA polymerase in transcription.
OR
Using a Punnett square, work out the distribution of phenotypic features in the first filial generation after a cross between a homozygous female and a heterozygous male for single locus.
Answer:
The DNA dependent RNA polymerase plays a role as a catalyst in RNA synthesis. So as to transcribe a gene; the RNA polymerase proceeds through the steps grouped as:
1. Initiation: In this step, the RNA polymerase binds with the promoter region of the DNA. The promoter polymerase complex, then undergoes structural changes that are essential for transcription.
2. Elongation : In this step, the RNA polymerase unwinds the DNA in front and tunnels it behind. It dissociates the growing RNA chain from the template as it moves along.
3. Termination : Once the polymerase transcribes the length of the gene, it stops and releases newly produced molecule RNA.

OR

To explain the concept, we can take an example of body colour Grey (G) and Albino (g). As per the question a Homozygous female (gg) having albino colour is crossed with heterozygous male (Gg) having Grey colour. By using Punnett square the following conclusions can be derived,
Parents Hetrozygous male (Gg) x Homozygous female (gg)

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 24

 

 

 

 

 

Question 25.
A person in your colony has recently been diagnosed with AIDS. People/Residents in the colony want him to leave the colony for the fear spread of AIDS. Write your views on the situation, listing reasons.
Answer:
1. AIDS is infectious but not contagious, it does not spread by shaking hand and use of common utensils so there is no need of fear to live with AIDS patient.
2. Making blood (from blood banks) safe from HIV, ensuring the use of only disposable needles and syringes in public and private hospitals and clinics, free distribution of condoms, controlling drug abuse, advocating safe sex and promoting regular check-ups for HIV in susceptible populations, are some such steps taken up to control AIDS

Question 26.
Mention a product of human welfare obtained with the help of each one of the following microbes:
(a) LAB
(b) Saccharomyces cerevisiae
(c) Propionibacterium shermanii
Answer:
(a) These bacteria, are usually found in decomposing plants and milk products, produce lactic acid as the major metabolic end product of carbohydrate fermentation.
(b) It has been used in wine making, baking and brewing since ancient times.
(c) Members of the genus Propionibacterium are widely used in the production of vitamin B12, tetrapyrrole compounds and propionic acid, as well as in the probiotics and cheese industries

Question 27.
Explain, giving three reasons, why tropics show greatest levels of species diversity.
Answer:
1. Tropical latitude has remained relatively undisturbed for millions of years so they have greatest level of species diversity.
2. Tropical environment is less seasonal, relatively more constant and predictable. Such constant environment promotes niche specialisation and leads to a greater species diversity.
3. There is more solar energy available in the tropics which contributes to higher productivity, so indirectly contribute to greater diversit

Question 28.
(a) Why must a cell be made ‘competent’ in biotechnology experiments? How does calcium ion help in doing so?
(b) State the role of ‘biolistic gun’ in biotechnology experiments.
Answer:
(a) DNA being a hydrophilic molecule, cannot pass through cell membranes, hence the cells should be made competent to accept the DNA molecules as competency is the ability of a cell to take up foreign DNA. Calcium ion helps in increasing the pore size in cell wall which enables the cell to take up the recombinant DNA.

(b) To introduce alien DNA into host cells, suitable for plants, cells are bombarded with high velocity micro-particles of gold or tungsten coated with DNA molecules known as biolistic or gene gun which plays an important role in biotechnology experiments.

Section – D (8 Marks)

Questions No. 29 and 30 are case based questions. Each question has subparts with internal choice in one subpart.

Question 29.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 29

Study the figure given above and answer the questions that follow:
(a) Name the process that the figure depicts.
(b) Name the strands marked “A” and “B”.
(c) Differentiate between strand “A” and “B”
OR
(c) Name the enzymes used for the process.
Answer:
(a) This process is known as DNA replication.
(b) “A” strand is leading strand and “B” is lagging strand.
(c) The leading strand is synthesised continuously but the opposite strand is copied in short bursts of about 1000 bases, as the lagging strand template becomes available. The resulting short strands are called Okazaki fragments.

OR

(c) DNA polymerases, helicases, topoisomerase, primase.

Question 30.
Given below is the diagram of female reproductive system. Consider the diagram and answer the questions based upon it.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 30

a) What does A represents?
(b) Define the role of B.
(c) Why is C important in female reproductive system?
OR
(c) What does D represent and what function does it play?
Answer:
(a) It is an ovary from where the ovum is released.
(b) B represents the cervix. The function of the cervix is to allow flow of menstrual blood from the uterus into the vagina, and direct the sperms into the uterus during intercourse. The opening of the cervical canal is normally very narrow.
(c) It is endometrium. The endometrium is the innermost glandularlayer and functions as a lining for the uterus, preventing adhesions between the opposed walls of the myometrium, thereby maintaining the patency of the uterine cavity.

OR

(c) D represents fundus. Fundus of the uterus is the upper flat or dome like part of uterus. Fundus of the uterus is usually the place where egg implants.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions

Section – E (15 Marks) 

Question 31.
The graph shows the changes in the levels of ovarian hormones in various phases of the menstrual cycle:

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 31

(a) From the graph identify hormone ‘A’ and ‘B’.
(b) Name the parts that produce hormone marked in the diagram.
(c) State why the level of A peaks before B.
(d) Compare the role of A and B.
(e) What is the period between 2 consecutive menstrual cycles?
OR
The figure below shows different phases of menstrual cycle.

C:\Users\Madura\Pictures\CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 31.png

 

 

 

 

 

 

Answer the questions following the diagram:
(a) State the levels of FSH, LH and progesterone simply by mentioning high or low around 13th and 14th day and 21st to 23rd day.
(b) In which phase egg travels to fallopian tube?
(c) What are the uterine events that follow beyond 29 days if the ovum is not fertilised?
(d) What is meant by L.H.Surge? Write the role of L.H.
(e) Name the process of rupture of Graafian follicle and the subsequent release of egg from the ovary.
Answer:
(a) Flormone “A” is estrogen and “B” is progesterone.
(b) Graafin follicle secretes estrogen whereas corpus luteum secretes progesterone.

(c) At ovulation, usually around day 12-14, there is increase in level of estrogen that triggers a sharp rise in Luteinizing Hormone (LH) from the pituitary gland, causing release of the egg from the follicle. The ruptured follicle (corpus luteum) now secretes progesterone and estrogen to continue to prepare the uterus for pregnancy. If the egg is not fertilised, estrogen and progesterone levels drop and on day 28, the menses begin.

(d) Estrogen: It is a female sex hormones and is also referred as growing hormone because of its role in the body. It is responsible for growing and maturing the uterine lining and also matures the egg prior to ovulation. Estrogen is produced mostly by the ovaries but also in smaller amounts by the adrenal glands and in fat tissue. It is most abundant in the first half of the menstrual cycle (follicular phase).

Progesterone: It is another female sex hormone which balances the effects of estrogen and is often referred to as the relaxing hormone. Progesterone is produced after ovulation by the corpus luteum and dominates the second half of the cycle (luteal phase). It controls the buildup of the uterine lining and helps to mature and maintain the uterine lining if there is a pregnancy. If there is no pregnancy, the progesterone levels fall and the lining of the uterus is shed, beginning the menstrual cycle.
(e) There is a period of 28 days between 2 consecutive menstrual cycles.

OR

(a)

13th and 14th Day 21st to 23rd Day
FSH High Low
LH High Low
Progesterone Low High

(b) End of follicular or proliferative phase.
(c) After 29th day there is a menstrual flow involving discharge of blood and shed off endometrium lining.
(d) Luteinising Hormone (LH, also known as lutropin and sometimes lutrophin) is produced by gonadotropic cells in the anterior pituitary gland. In females, an acute rise of LH is referred as “LH surge” triggers ovulation and development of the corpus luteum. In males, LH is referred as Interstitial Cell Stimulating Hormone (ICSH), which stimulates the Leydig cell production of testosterone. It acts synergistically with FSH.
(e) Ovulation

Question 32.
(a) Differentiate between active and passive immunity.
(b) Comment on the role of vaccination and immunisation in keeping human population healthy.
OR
A sedative or tranquillizer is a substance that induces sedation by reducing irritability or excitement. They are central nervous depressants and interact with brain activity causing its deceleration. Various kinds ofsedatives can be distinguished, but the majority of them affect the neurotransmitter. For example morphine. Morphine is used as a sedative as well as a pain killer drug. Give an account on various uses of Morphine. What are the precautionary measures before using this drug? What are the side effects of this kind of drug?
Answer:
(a)

S. No. Active Immunity Passive Immunity
1. Involves bodies direct response to an unknown pathogen. Involves antibodies obtained from outside the body.
2. Antibodies are produced specific to the antigen of a particular pathogen. Antibodies are obtained from outside.
3. Not immediate as it takes time to create enough of the correct antibodies to fight the pathogen. Immediate, as no time is needed to create antibodies since they are obtained from outside.

(b) Immunisation is the process whereby a person is made immune or resistant to an infectious disease, typically by the enfection or incoopration of a vaccine in body. Vaccines stimulate the body’s own immune system to protect the person against subsequent infection or disease. Immunisation is one of the best ways to wipe out disease that could spread now and into the future.

Vaccination has greatly reduced the burden of infectious diseases. Vaccines also generate memory cell (B and T cells) that recognize quickly on subsequent exposure and controls growth of pathogen with massive production of antibodies. Preformed antibodies protect our body from deadly microbes like tetanus and against snake venom.

OR

Morphine is used to help relieve moderate to severe pain. It belongs to a class of drugs known as opioid (narcotic) analgesics. It works in the brain to show how the body feels and responds to pain.
1. Precautions : Before taking morphine, inform your doctor or pharmacist if you are allergic to it; or to other opioid pain medications or if you have any other severe allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

2. Side effects : The common side effects of morephine consult are nausea, vomiting, constipation, lightheadedness, dizziness, drowsiness or sweating may occur. Some of these side effects may decrease after you have been using this medication for a while. If any of these effects persist or worsen, tell your doctor or pharmacist promptly

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions

Question 33.
Define transcription. Give salient features of genetic codes.
OR
Describe the termination process of transcription in bacteria.
Answer:
Transcription is the process of copying the genetic information from one strand of DNA into RNA. Some salient features of genetic code are as follows:
1. Every codon is triplet in nature. Sixty one codons code for amino acids. Three codons do not code for any amino acid. These are termed as stop codons.
2. The codon is read in contiguous pattern in mRNA.
3. Codes are universal in nature.
4. Codons are unambiguous and specific because one codon codes only one amino acid at a time.
5. Some codons code for more than one amino acid. Such codes are discrete in nature.
6. The code AUG is dual in function as it codes for, the Methionine and also acts as an initiator codon.

OR

The process of transcription in bacteria starts with the RNA polymerase getting binded to the promoter and this initiates the process of transcription. By following the rule of complementary, it utilises nucleotide triphosphate as a substrate and polymerises in a template dependent fusion. It helps in opening the double helical structure followed by the process of elongation.

Thus only short stretch of RNA remains attached to an enzyme. Once the polymerase reaches the region of termination, the nascent RNA falls off along with RNA polymerase. These consequents into the termination of transcription. The RNA polymerase associates transiently with terminate on rho factor (r) to terminate the transcription. Association of this factor alters the specificity of RNA polymerase to terminate.

CBSE Sample Papers for Class 12 Biology Set 5 with Solutions Q 33