CBSE 12 Biology Question Paper-2022 Set-2 - Practice Test
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  2. Practice Tests
  3. CBSE 12 Biology Question Paper-2022 Set-2
CBSE 12 Biology Question Paper-2022 Set-2

CBSE 12 Biology Question Paper-2022 Set-2 - Practice Test

This mock test includes actual CBSE Class 12 Biology board exam questions from the year 2022 Set-2, helping students understand exam trends and practice real paper format

2025-08-13
Pavan Pavan
CBSE Class 12 Biology 2022 Grade 12

Duration

30 min

Questions

30

Marking

Negative

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Questions Preview

Lactic Acid Bacteria (LAB) sets milk into curd and also plays a very beneficial role for human health. Give any two suitable reasons.

A
Lactic Acid Bacteria help in digestion and improve gut health.
B
Lactic Acid Bacteria are responsible for causing infections.
C
Lactic Acid Bacteria enhance the shelf-life of dairy products.
D
Lactic Acid Bacteria are harmful and should be avoided.

A person suffering from AIDS dies of opportunistic infections (ARC) i.e., infections that could have been otherwise overcome. Give the scientific name of one bacterium and one parasite which mainly attack a person suffering from AIDS.

A
Bacterium: Escherichia coli, Parasite: Entamoeba histolytica
B
Bacterium: Staphylococcus aureus, Parasite: Hookworm
C
Bacterium: Mycobacterium tuberculosis, Parasite: Plasmodium falciparum
D
Bacterium: Salmonella typhi, Parasite: Toxoplasma gondii

Though filariasis is not fatal, but the disease in humans is responsible for considerable suffering, gross deformities and disability. Write the scientific name of any two helminth worms causing the disease and state two chronic manifestations of filariasis.

A
Wuchereria bancrofti, Brugia malayi. Chronic manifestations include Elephantiasis and Hydrocele.
B
Taenia solium, Echinococcus granulosus. Chronic manifestations include Cysticercosis and Seizures.
C
Ancylostoma duodenale, Necator americanus. Chronic manifestations include Anemia and Fatigue.
D
Ascaris lumbricoides, Trichuris trichiura. Chronic manifestations include Abdominal pain and Diarrhea.

State two morphological attributes observed in the leaves of desert plants that enable them to survive in extreme conditions in the desert.

A
Leaves are thick and fleshy to store water, and they have a waxy coating to prevent water loss.
B
Leaves are long and narrow to absorb maximum sunlight, and they have a deep root system.
C
Leaves are colorless to absorb more heat, and they are covered with fine hairs to trap moisture.
D
Leaves have multiple layers of epidermis for better protection and they shed during dry seasons.

Which one of the two biogas plants can be used for generating gas fuel and electricity and why?

A
The plant with a single chamber for all types of waste can only generate gas fuel.
B
The plant with two separate chambers for solid waste and slurry can generate both gas fuel and electricity.
C
The plant with no provision for waste separation can generate neither gas nor electricity.
D
The plant with mechanical stirring can only generate electricity.

Write the scientific name of one bacterium and one parasite which mainly attack a person suffering from AIDS.

A
Bacterium: Mycobacterium tuberculosis, Parasite: Plasmodium falciparum
B
Bacterium: Escherichia coli, Parasite: Entamoeba histolytica
C
Bacterium: Salmonella typhi, Parasite: Toxoplasma gondii
D
Bacterium: Staphylococcus aureus, Parasite: Hookworm

Vaccination has been the most effective medical strategy to control infectious diseases. Explain the principle on which vaccination works.

A
Vaccination directly kills pathogens in the body.
B
Vaccination prevents the entry of viruses into the body.
C
Vaccination works by stimulating the immune system to produce antibodies without causing disease.
D
Vaccination increases the body's ability to fight off bacterial infections only.

How has the introduction of Nile Perch into Lake Victoria in East Africa had a devastating effect on the indigenous species in the lake?

A
Nile Perch has made the lake more suitable for fish farming.
B
Nile Perch has helped increase the biodiversity of the lake.
C
Nile Perch has had no significant effect on the lake's ecosystem.
D
Nile Perch has led to the extinction of many native species by preying on them.

When Plasmodium sp. enters the human body, it reproduces asexually and increases its number. After a number of asexual cycles, the parasite enters the sexual phase of its life. Trace the sexual stages in the life cycle of Plasmodium in a female Anopheles mosquito.

A
The sexual stages involve gametocyte formation, fertilization, and sporozoite development in the mosquito.
B
The sexual stages involve sporulation in the human liver before transmission.
C
The sexual stages involve oocyst formation within human cells.
D
The sexual stages do not involve any transformation in the mosquito.

In which step of recombinant DNA technology is foreign DNA integrated with the vector DNA?

A
Foreign DNA is integrated in the ligation step using ligase enzyme.
B
Foreign DNA is integrated in the restriction enzyme cutting step.
C
Foreign DNA is integrated in the transformation step.
D
Foreign DNA is integrated in the selection step.

What is the term used for step (Y) showing multiple copies of the foreign DNA being formed in transformed E. coli?

A
Cloning
B
Ligation
C
Transformation
D
Amplification

Which of the following is an example of a genetic disorder related to cholesterol metabolism?

A
Familial hypercholesterolemia
B
Cystic fibrosis
C
Hemophilia
D
Down syndrome

What is the basic principle involved in RNA interference (RNAi) in silencing the preferred genes?

A
RNAi works by degrading mRNA molecules that correspond to specific genes, preventing their expression.
B
RNAi works by increasing the production of specific proteins.
C
RNAi works by enhancing gene mutation rates.
D
RNAi works by causing errors in protein synthesis.

What is the scientific principle behind genetic engineering?

A
Genetic engineering involves manipulating the DNA of organisms to achieve desired traits.
B
Genetic engineering only focuses on cloning organisms without altering their DNA.
C
Genetic engineering involves breeding two species to produce hybrids.
D
Genetic engineering relies on mutating genes using radiation.

What role does the enzyme ligase play in recombinant DNA technology?

A
Ligase enzyme joins the foreign DNA with the vector DNA.
B
Ligase enzyme cuts the DNA into fragments.
C
Ligase enzyme amplifies the DNA fragments.
D
Ligase enzyme separates the DNA strands.

What is the role of a plasmid in genetic engineering?

A
Plasmids act as vectors that carry foreign genes into host cells.
B
Plasmids protect the organism from bacterial infection.
C
Plasmids inhibit the growth of bacterial colonies.
D
Plasmids provide energy for bacterial cells.

Which of the following is NOT a step in recombinant DNA technology?

A
Amplification of DNA using polymerase chain reaction (PCR)
B
Ligation of foreign DNA into a plasmid vector
C
Synthesis of new genes by artificial gene synthesis
D
Spontaneous mutation of the host organism's genome

What is PCR (Polymerase Chain Reaction) used for in genetic engineering?

A
PCR is used to amplify specific segments of DNA.
B
PCR is used to cut DNA into fragments.
C
PCR is used to insert foreign genes into host DNA.
D
PCR is used to extract DNA from cells.

Which of the following is the main advantage of recombinant DNA technology in agriculture?

A
It allows for the creation of genetically modified crops with improved traits.
B
It increases the size of crops but reduces their resistance to pests.
C
It helps in the crossbreeding of plant species to create new hybrids.
D
It prevents the growth of weeds by altering their genetics.

What is the purpose of using restriction endonucleases in genetic engineering?

A
They cut DNA molecules at specific sequences to create fragments.
B
They amplify DNA by copying it repeatedly.
C
They insert foreign genes into plasmids.
D
They prevent the replication of harmful DNA.

Which of the following organisms is used as a host for cloning genes in genetic engineering?

A
E. coli bacteria
B
Yeast
C
Mice
D
Plants

What is a vector in genetic engineering?

A
A vector is a DNA molecule used to carry foreign genetic material into a host cell.
B
A vector is an organism that spreads infectious diseases.
C
A vector is a chemical compound that enhances gene expression.
D
A vector is an antibiotic used to select transformed cells.

Which of the following is the main disadvantage of genetically modified organisms (GMOs)?

A
GMOs may have unintended ecological consequences.
B
GMOs are less nutritious than non-GMO crops.
C
GMOs have a higher market cost than conventional crops.
D
GMOs always result in higher yields but reduced resistance to diseases.

What is PCR (Polymerase Chain Reaction) used for in genetic engineering?

A
PCR is used to amplify specific segments of DNA.
B
PCR is used to cut DNA into fragments.
C
PCR is used to insert foreign genes into host DNA.
D
PCR is used to extract DNA from cells.

What is the first step in the process of genetic engineering?

A
Isolation of the gene of interest.
B
Insertion of the gene into the vector.
C
Transformation of the host organism.
D
Selection of the transformed cells.

Which of the following is an example of a genetically modified organism (GMO)?

A
Bt cotton that is resistant to insect pests.
B
Wheat that has been naturally crossbred to increase yield.
C
Tomatoes that are grown in high-altitude regions.
D
Cabbages that are resistant to cold temperatures.

What is the ethical concern surrounding the use of GMOs?

A
GMOs may have unintended ecological consequences.
B
GMOs cause a shortage of natural food sources.
C
GMOs lead to a decrease in crop production.
D
GMOs always result in loss of biodiversity.

Which of the following is a method of gene transfer in plants?

A
Using the Agrobacterium tumefaciens bacterium as a vector.
B
Injecting DNA directly into the plant cells using a syringe.
C
Inducing natural hybridization between different plant species.
D
Using a viral vector to infect plant cells.

What is the purpose of adding antibiotic resistance genes to genetically modified organisms?

A
To help identify and select transformed cells that contain the desired genetic material.
B
To make the organism more resistant to bacterial infections.
C
To enhance the growth rate of the organism.
D
To prevent the organism from being harmed by herbicides.

Which of the following is a major application of recombinant DNA technology in medicine?

A
Production of insulin and growth hormones.
B
Production of plant-based vaccines.
C
Production of synthetic proteins for food supplements.
D
Enhancement of crop resistance to pests.