Category: Class 12 Biology Objective Questions

Biology Quiz for Class 12 on “Biotechnological Applications in Medicine: Molecular Diagnosis – 2”.

1. ELISA stands for _______
a) Enzyme Like Immuno-sorbent Assay
b) Enzyme-Linked Immuno-sorbent Assay
c) Enzyme-Linked Immuno-similar Assay
d) Enzyme-Linked Immuno-sorbent Array
Answer: b
Clarification: ELISA stands for Enzyme-Linked Immuno-sorbent Assay. It is a technique used for the detection and quantification of various substances such as hormones, peptides, antibodies, etc. it is used for the detection of many diseases.

2. A ______ of a disease helps to suspect the presence of pathogen within the body.
a) disease
b) symptom
c) consequence
d) effect
Answer: b
Clarification: A symptom of a disease helps to suspect the presence of pathogens within the body. A symptom is a physical and mental feature that indicates the condition of the disease. Symptoms of diseases can be the same or vary according to person and disease.

3. Low concentration of any pathogen can be detected by ______ of their nucleic acid.
a) cutting
b) amplification
c) joining
d) denaturation
Answer: b
Clarification: Low concentration of any pathogen can be detected by amplification of their nucleic acid. Amplification means increasing the number. The high number of nucleic acid can ease in finding pathogens, symptoms and cure against it.

4. Amplification of nucleic acid can be done with the help of ______
a) Centrifugation
b) RDT
c) ELISA
d) PCR
Answer: d
Clarification: Amplification of nucleic acid can be done with the help of PCR. PCR stands for Polymerase Chain Reaction. It was developed by Kary Mullis in 1893.

5. PCR is used to detect _____ in patients having AIDS.
a) pneumonia
b) fever
c) HIV
d) cough
Answer: c
Clarification: PCR is used to detect HIV in patients having AIDS. PCR is used to detect the genetic material of the HIV virus that is RNA. It is used to detect early infections within the patient’s body.

6. PCR is used to detect _______ in cancer patients.
a) fever
b) mutations
c) cold
d) cough
Answer: b
Clarification: PCR is used to detect mutations in cancer patients. It is used to find out certain changes in the genetic material of an organism, specific gene or chromosome. Thus it is useful for the detection of various genetic disorders including cancer.

7. ______ can be used to identify genetic disorders.
a) Centrifugation
b) PCR
c) Chromatography
d) RIA
Answer: b
Clarification: PCR can be used to identify genetic disorders. Amplification of nucleic acid can be done with the help of PCR and is used to find out certain changes in the genetic material of an organism, specific gene or chromosome.

8. A single-stranded DNA or RNA tagged with a radioactive molecule is called ______
a) prove
b) ssDNA
c) probe
d) ssRNA
Answer: c
Clarification: A single-stranded DNA or RNA tagged with a radioactive molecule is called a probe. It is an oligonucleotide used for the amplification of nucleic acids in PCR. They emit fluorescence after successful binding with the sequence.

9. Probes ________ with its complementary DNA.
a) separate
b) stand
c) add
d) hybridize
Answer: d
Clarification: Probes hybridize with its complementary DNA. The probe is a single-stranded DNA or RNA tagged with a radioactive molecule that is used in PCR for the amplification of genetic material.

10. The hybrid of the radioactive probe and its complementary DNA is detected by ______
a) ELISA
b) RIA
c) autoradiography
d) PCR
Answer: c
Clarification: The hybrid of the radioactive probe and its complementary DNA is detected by autoradiography. Autoradiography is a technique that uses X-rays for the detection of radioactive substances. When exposed to X-rays the radioactive material emits light which helps in their detection.

11. Autoradiography is used for the detection of ______
a) cold
b) cancer
c) fatigue
d) fever
Answer: b
Clarification: Autoradiography is used for the detection of cancer. It is used for the detection of radioactive material in any biological specimen. It is used in the detection of target receptors in various tissues.

12. ELISA is based on the principle of _______ reaction.
a) antibody-antibody
b) antigen-antigen
c) antigen-antibody
d) DNA-RNA
Answer: c
Clarification: ELISA is based on the principle of antigen-antibody reaction. It is used for the detection of proteins, antibodies, etc. produced by a person against that specific antigen. It is used for the detection of various diseases such as HIV, AIDS, syphilis, etc.

13. Which technique depends on the antigen- antibody reaction?
a) PCR
b) ELISA
c) Chromatography
d) RDT
Answer: b
Clarification: ELISA is a technique that depends on the antigen-antibody reaction. The human body produces antibodies against all types of antigens. Thus ELISA is used for the detection of the antibodies which helps in the detection of various diseases.

14. In ELISA the antigens can be _____
a) antibody
b) urine
c) serum
d) proteins
Answer: d
Clarification: In ELISA the antigens can be proteins, glycoproteins or any part of that antigen. In this antigens or part of an antigen is attached to the surface against which antibodies are available. Thus ELISA is a technique that depends on the antigen-antibody reaction.

15. In ELISA ______ synthesized by the pathogen can be detected.
a) proteins
b) urine
c) serum
d) antibody
Answer: a
Clarification: In ELISA proteins synthesized by the pathogen can be detected. It can be used in the detection of any cell component of the pathogen such as glycoproteins, nucleic acids, etc.

16. Antibodies are secreted against the _____
a) antigen
b) animals
c) cells
d) antibodies
Answer: a
Clarification: Antibodies are secreted against the antigen. Antibodies are the immunoglobulin which binds with the antigen and eliminates it. These are developed by the immune system of humans.

To practice Biology Quiz for Class 12,

Biology Multiple Choice Questions on “Population Growth – 1”.

1. Which of the following process is responsible for fluctuation in population density?
a) Mimicry
b) Natality
c) Hibernation
d) Age structure
Answer: b
Clarification: Natality is responsible for fluctuation in population density. It is the number of individuals born in a population at a specific time. For humans, it is described as a number of individuals born per 1000 of the population per year.

2. Which letter is used to designate the birth rate (Natality)?
a) B
b) E
c) I
d) K
Answer: a
Clarification: Natality (birth rate) is designated by the letter ‘B’. It is the number of individuals born in a population at a specific time. For humans, it is described as a number of individuals born per 1000 of the population per year.

3. Which of the following correctly tells about population density at time t+1?
a) N_t + 1 = N_t + [(B + I) – (I + E)]
b) N_t + 1 = N_t + [(B + I) – (D + E)]
c) N_t + 1 = N_t + [(B + D) – (B + E)]
d) N_t + 1 = -N_t + [(B + I) – (D + E)]
Answer: b
Clarification: The population density at time t+1 is given as N_t + 1 = N_t + [(B + I) – (D + E)]. Here Nt is population at time t, B is natality, I is immigration, D is mortality while E is emigration.

4. Which of the following process is responsible for fluctuation in population density?
a) Aestivation
b) Camouflage
c) Hibernation
d) Mortality
Answer: d
Clarification: Mortality is responsible for fluctuation in population density. It is the number of individuals died in a population at a specific time. For humans, it is described as a number of deaths per 1000 of the population per year.

5. Which of the following is responsible for an increase in population density?
a) Age structure
b) Emigration is more
c) Immigration is more
d) Death rate increase
Answer: c
Clarification: Population density increases when there is an increase in immigration. It is an act of coming into a different country of which they are not natives and reside permanently. This increases the population density of an area where they are residing.

6. Which letter is used to designate the death rate (Mortality)?
a) J
b) D
c) S
d) U
Answer: b
Clarification: The mortality (death rate) is designated by ‘D’. It is the number of individuals died in a population at a specific time. For humans, it is described as a number of deaths per 1000 of the population per year.

7. Which of the following process is responsible for fluctuation in population density?
a) Hibernation
b) Aestivation
c) Mimicry
d) Immigration
Answer: d
Clarification: Immigration is responsible for fluctuation in population density. It is an act of coming into a different country of which they are not natives and reside permanently. This increases the population density of an area where they are residing.

8. Which of the following is responsible for an increase in population density?
a) Death rate increase
b) Age structure
c) Birth rate increase
d) Emigration is more
Answer: c
Clarification: The increase in birth rate (natality) is responsible for an increase in population density. Natality is the number of individuals born in a population at a specific time. The population density tells about the number of individuals in a unit area (per square meter, per square kilometer or per hectare) at a specific time.

9. Which letter is used to designate the immigration?
a) A
b) K
c) S
d) I
Answer: d
Clarification: Immigration is designated by the letter ‘I’. Immigration is responsible for fluctuation in population density. It is an act of coming into a different country of which they are not natives and reside permanently.

10. Which of the following is responsible for a decrease in population density?
a) Birth rate increase
b) Immigration is more
c) Emigration is more
d) Age structure
Answer: c
Clarification: The population density decreases when emigration is more. Emigration is an act of leaving one’s own country and settling or residing in another country (abroad) permanently.

11. Under normal conditions which of the following factor is responsible for influencing population density?
a) Pyramid
b) Births
c) Immigration
d) Emigration
Answer: b
Clarification: Under normal conditions, the population density is influenced by births in an area at a specific time i.e. birth rate. The increase in birth rate (natality) is responsible for an increase in population density.

12. Under normal conditions which of the following factor is responsible for influencing population density?
a) Pyramid
b) Immigration
c) Deaths
d) Emigration
Answer: c
Clarification: Under normal conditions, the population density is influenced by deaths in an area at a specific time i.e. death rate (mortality). It is the number of individuals died in a population at a specific time.

13. Which letter is used to designate the emigration?
a) J
b) E
c) U
d) V
Answer: b
Clarification: The letter used to designate emigration is ‘E’. Emigration is an act of leaving one’s own country and settling or residing in another country (abroad) permanently.

14. Which of the following is responsible for a decrease in population density?
a) Birth rate increase
b) Immigration is more
c) Age structure
d) Death rate increase
Answer: d
Clarification: The increase in death rate (mortality) is responsible for a decrease in population density. The death rate is the number of individuals died in a population at a specific time. The population density tells about the number of individuals in a unit area (per square meter, per square kilometer or per hectare) at a specific time.

15. Which of the following process is responsible for fluctuation in population density?
a) Emigration
b) Age structure
c) Mimicry
d) Camouflage
Answer: a
Clarification: The emigration is responsible for fluctuation in population density. The population density decreases when emigration is more. Emigration is an act of leaving one’s own country and settling or residing in another country (abroad) permanently.

Biology Multiple Choice Questions for Pharmacy Entrance Exams on “Ecosystem – Energy Flow – 2”.

1. What is a group of organisms that transfer food energy through a linear series of processes such as eating and being eaten called?
a) Detritus
b) Food chain
c) Decomposers
d) Producers
Answer: b
Clarification: A group of organisms that transfer food energy through a linear series of processes such as eating and being eaten is known as a food chain. A food chain always proceeds in a progressive straight line and intertwine into food webs.

2. What is a network of food chains interconnecting at various trophic levels and representing feeding relationships within a community called?
a) Food web
b) Decomposers
c) Herbivores
d) Food industry
Answer: a
Clarification: A network of food chains interconnecting at various trophic levels and representing feeding relationships within a community is called a food web. Food webs are formed because of interdependency such that an animal feeds on a plant or on another animal and in turn, becomes food for another.

3. What is the food chain beginning with host and ending with a parasite (ecto as well as endoparasite) called?
a) Detritus food chain
b) Parasitic food chain
c) Grazing food chain
d) Terrestrial food chain
Answer: b
Clarification: A group of organisms that transfer food energy through a linear series of repeated processes of eating and being eaten is called a food chain. The food chain beginning with host and ending with a parasite (ecto as well as endoparasite) is called a parasitic food chain.

4. What are the organisms that cannot manufacture their own food and obtain ready-made organic food from producers called?
a) Decomposers
b) Autotrophs
c) Scavengers
d) Consumers
Answer: d
Clarification: The organisms that cannot manufacture their own food and obtain ready-made organic food from producers are called consumers. These are heterotrophic organisms belonging from second to fifth trophic level.

5. To which trophic level do producers (photosynthesizers or autotrophs) belong?
a) Second
b) Third
c) First
d) Fifth
Answer: c
Clarification: Producers are organisms that make their own food with the help of energy obtained from chemicals or the sun, water, and air. They belong to T₁ that is the first trophic level.

6. Which are the three types of consumers?
a) Autotrophs, heterotrophs, and decomposers
b) Herbivores, carnivores, and decomposers
c) Producers, heterotrophs, and decomposers
d) Herbivores, heterotrophs, and carnivores
Answer: b
Clarification: The organisms that cannot manufacture their own food and obtain ready-made organic food from producers are called consumers. The herbivores, carnivores, and decomposers are the three main types of consumers.

7. How many levels do carnivores occupy?
a) 8
b) 1
c) 5
d) 3
Answer: d
Clarification: The carnivores are the organisms that primarily and exclusively feed on other animals (herbivore or carnivore) for energy. They may occupy 2-3 trophic levels in an ecosystem.

8. To which trophic level do top or ultimate carnivores belong?
a) T₁
b) T₃
c) T₄
d) T₁₀
Answer: c
Clarification: The carnivores are the organisms that primarily and exclusively feed on other animals (herbivore or carnivore) for energy. The top or ultimate carnivores belong to T₄ or T₅ that is the fourth or fifth trophic level.

9. What is the step or division that organisms occupy in a food chain that is characterized by the method of obtaining its nutrition to fulfill its energy requirements called?
a) Trophic level
b) Food chain
c) Food web
d) Food pyramid
Answer: a
Clarification: The step or division that organisms occupy in a food chain that is characterized by the method of obtaining their nutrition to fulfill their energy requirements is known as a trophic level. The producers and consumers are the two fundamental trophic levels.

10. What is the number of trophic levels equal to?
a) Number of producers
b) Number of consumers
c) Number of divisions in a food chain
d) Number of carnivores
Answer: c
Clarification: The step or division that organisms occupy in a food chain that is characterized by the method of obtaining their nutrition to fulfill their energy requirements is known as a trophic level. The number of trophic levels is equivalent to the number of divisions in a food chain.

11. Which organisms are included in the last trophic level?
a) Autotrophs
b) Decomposers
c) Carnivores
d) Producers
Answer: b
Clarification: The decomposers occupy the last trophic level that is T₆. It is also known as the detritus trophic level. They are the last organisms belonging to a food chain.

12. Which organisms do not have any fixed trophic levels?
a) Decomposers
b) Autotrophs
c) Parasites
d) Carnivores
Answer: c
Clarification: Parasites are the organisms that do not have any fixed trophic levels. This is because they feed producers (autotrophs), herbivores as well as carnivores (consumers) of different trophic levels, e.g. Cuscuta, ticks, leeches, mosquitoes, etc.

13. What is a parasitic food chain alternatively called?
a) Detritus food chain
b) Auxilliary food chain
c) Grazing food chain
d) Trophic level
Answer: b
Clarification: The food chain beginning with host and ending with a parasite (ecto as well as endoparasite) is called a parasitic food chain. It is alternatively called an auxiliary food chain.

14. What is a food chain beginning with detritus on which decomposers feed called?
a) Grazing food chain
b) Parasitic food chain
c) Primary food chain
d) Detritus food chain
Answer: d
Clarification: A food chain beginning with detritus on which decomposers feed is known as the Detritus food chain (DFC). The organisms that are responsible for the break down complex organic matter (dead or decaying organisms) into inorganic substances are called decomposers (detritivores).

15. What is a food chain consisting of autotrophs, heterotrophs, and carnivores called?
a) Grazing food chain
b) Quaternary food chain
c) Parasitic food chain
d) Detritus food chain
Answer: a
Clarification: A food chain consisting of autotrophs (producers), heterotrophs, and carnivores (consumers) is known as a grazing food chain. It is the most common food chain and is designated as GFC.

To practice Biology Multiple Choice Questions for Pharmacy Entrance Exams,

Biology Exam Questions for Pharmacy Entrance Exams on “Biodiversity – Number of Species on Earth and in India”.

1. What does IUCN stand for?
a) International Union for Control of Disease
b) International Union for Conservation of Nature
c) International Unit of Nucleic acids
d) International Union of Carbohydrates and Nucleic acids
Answer: b
Clarification: International Union for Conservation of Nature (IUCN) was founded on 5 October 1948 in France by Julian Huxley. It is working in the field of conservation of nature and sustainable use of natural resources.

2. How many plant and animal species have been discovered and described so far?
a) 1.5 million
b) 4.5 million
c) 1.5 billion
d) 4.5 billion
Answer: a
Clarification: The biosphere of Earth is heterogeneous in nature and shows immense diversity. There are more than slightly more than 1.5 million species known and still many species are yet to be discovered and described.

3. What is the global species diversity according to Robert May?
a) 70 million
b) 7 million
c) 2 million
d) 20 million
Answer: b
Clarification: Robert McCredie May is a theoretical ecologist and promoter of science. He estimated that there are almost 7 million species globally.

4. Out of the total species estimated, how many species are of animals?
a) 2 %
b) 50 %
c) 7 %
d) 70 %
Answer: d
Clarification: Based on the currently available species inventories of Earth, out of all species recorded, more than 70 percent of species are of animals. Animals are the consumers that depend on producers for their energy requirements.

5. Of all the species recorded, what percent do plants comprise of?
a) 10 %
b) 50 %
c) 22 %
d) 2 %
Answer: c
Clarification: Based on the currently available species inventories of Earth, out of all species recorded, almost 22 percent of species are of plants. These include all the known species of (including algae, fungi, bryophytes, gymnosperms, and angiosperms.

6. Of all the animal species recorded, what percent do insects comprise of?
a) 7 %
b) 70 %
c) 50 %
d) 2 %
Answer: b
Clarification: Among animals, insects are said to be the most species-rich taxonomic group. Insects are hexapod invertebrates belonging to phylum Arthropoda. Out of all known animal species, 70 percent is comprised of insects.

7. Which is the most species-rich taxonomic group?
a) Molluscs
b) Crustaceans
c) Echinoderms
d) Insects
Answer: d
Clarification: Among animals, insects are said to be the most species-rich taxonomic group. Insects are hexapod invertebrates belonging to phylum Arthropoda. Out of all known animal species, 70 percent is comprised of insects.

8. Of all the vertebrate species recorded which class has the maximum number of species?
a) Amphibians
b) Mammals
c) Fishes
d) Reptiles
Answer: c
Clarification: Fishes are limbless cold-blooded vertebrate gill-bearing aquatic craniate animals. They commonly have fins and are covered with scales. Of all the vertebrate species recorded, fishes have the maximum number of species.

9. Of all the plant species recorded which class has the minimum number of species?
a) Angiosperms
b) Fungi
c) Algae
d) Lichens
Answer: d
Clarification: The mutualistic relationship between a fungus and photosynthesizing algae is called lichens. Of all the plant species recorded, lichens have the minimum number of species. They are used in the food industry, making dyes and have medicinal use.

10. How much of the world’s land area, India has?
a) 1 percent
b) 40 percent
c) 2.4 percent
d) 80 percent
Answer: c
Clarification: Of the entire world’s land area, India has 2.4 percent. India with a total area of 3,287,263 square kilometers that is 1,269,219 square miles is said to be the seventh-largest country in the world.

11. Which of the following species is present in India?
a) Koala
b) Sloth bear
c) Kangaroo
d) Wombats
Answer: b
Clarification: Out of the total global species diversity, India contributes 8.1 percent. Out of this sloth bear is found in India, while rest others are marsupials that are mostly found in Australia.

12. Which of the following species is native of India?
a) Rhodes grass
b) Jackalberry tree
c) Ebony tree
d) Umbrella thorn acacia
Answer: c
Clarification: India is home to approximately 45,000 plant species. Ebony tree (Diospyros celibica) is the native of India. It is a threatened species found in Karnataka.

13. Considering May’s global estimates, how many of the total species have been recorded?
a) 1 percent
b) 22 percent
c) 10 percent
d) 50 percent
Answer: b
Clarification: Robert McCredie May is a theoretical ecologist and promoter of science. He estimated that there are almost 7 million species globally. Considering May’s global estimates, only 22 percent of the total species have been recorded.

14. Considering May’s global estimates, how many of the plant species are yet to be discovered and described in India?
a) 500
b) 100
c) 5,00,000
d) 1,00,000
Answer: d
Clarification: Robert McCredie May estimated that there are almost 7 million species globally. Considering May’s global estimates and applying this proportion to India’s diversity figures, we can say that there are more than 1,00,000 plant species yet to be discovered and described in India.

15. Considering May’s global estimates, how many of the animal species are yet to be discovered and described in India?
a) 3,00,000
b) 300
c) 30
d) 3
Answer: a
Clarification: Robert McCredie May estimated that there are almost 7 million species globally. Considering May’s global estimates and applying this proportion to India’s diversity figures, we can say that there are more than 3,00,000 animal species yet to be discovered and described in India.

To practice Biology Exam Questions for Pharmacy Entrance Exams,

Biology Multiple Choice Questions on “Environmental Issues – Deforestation”.

1. What is the process of removal of forest cover of an area called?
a) Afforestation
b) Deforestation
c) Pollution
d) Greenhouse effect
Answer: b
Clarification: The process of removal of forest covers of an area that is the conversion of forested areas to non-forested ones is known as deforestation. Almost 40 percent of forests in the tropics compared 1 percent in the temperate region have been lost due to this.

2. By the end of the twentieth century what percent of the land of India was covered by forests?
a) 19.4 %
b) 30.3 %
c) 50.5 %
d) 56.8 %
Answer: a
Clarification: Almost 30 percent of the land in India was covered by forests at the beginning of the twentieth century. This was reduced to 19.4 percent at the end of the century. The main reason for this depletion was increasing deforestation due to the increase in the human population.

3. In which of the following process the farmers cut down the trees of the forest and burn the plant remains?
a) Room cultivation
b) Jhum cultivation
c) Crop cultivation
d) Afforestation
Answer: b
Clarification: The process of growing crops by cutting down the trees and vegetation of the forest and burning the plant remains for agriculture is known as jhum cultivation. It is also known as the slash and burn agriculture and is mostly practiced in the north-eastern states of India.

4. Which one of the following is known as the slash and burn agriculture?
a) Afforestation
b) Crop cultivation
c) Room cultivation
d) Jhum cultivation
Answer: d
Clarification: The slash and burn agriculture includes growing crops by cutting down the trees and vegetation of the forest and burning the plant remains for agricultural use. It is also known as the jhum cultivation and is mostly practiced in the north-eastern states of India.

5. What is the process of re-growing a forest that once existed but was cut-down in the past called?
a) Deforestation
b) Jhum cultivation
c) Reforestation
d) Greenhouse effect
Answer: c
Clarification: The process of restoring or re-growing a forest that once existed but was removed or cut-down in the past is known as the reforestation. It is also known as afforestation. It may occur naturally but the process can be sped up by planting more trees.

6. For what reason was the Chipko Movement launched?
a) Protection of humans
b) Protection of forest
c) Protection of ponds and lakes
d) Protection of animals
Answer: b
Clarification: The Chipko Movement was a non-violent social and ecological movement by rural villagers launched for the protection of forests. It was done in 1974 in the Garhwal Himalayas.

7. Which award is given to the individuals or communities from rural areas that have shown a significant contribution and dedication in the protection of wildlife in the Country?
a) Arjuna Award
b) Padma Bhushan Award
c) Rajiv Gandhi Wildlife Conservation Award
d) Amrita Devi Bishnoi Wildlife Protection Award
Answer: d
Clarification: The individuals or communities from rural areas that have shown extraordinary courage, a significant contribution, and dedication in the protection of wildlife in the Country are awarded by the Amrita Devi Bishnoi Wildlife Protection Award. Along with this a cash award of rupees, one lakh is also given to that individual/community.

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