Category: Class 12 Biology Objective Questions

Biology Multiple Choice Questions on “Molecular Basis of Inheritance – DNA”.

1. Who was the first person to analyse factors?
a) Gross
b) Haeckel
c) Mendel
d) Altmann
Answer: c
Clarification: The first person to analyse and detect factors was Mendel. In fact, he was the person who gave the term factors. They were detected by following their patterns of transmission from generation to generation.

2. In which year, the mechanism for genetic inheritance reached the molecular level?
a) 1986
b) 1999
c) 1926
d) 1945
Answer: c
Clarification: The quest to determine the mechanism for genetic inheritance reached the molecular level in 1926. The nature of the genetic material was studied at that time and it was realised that DNA is the genetic material for the majority of organisms.

3. What is the full form of DNA?
a) Degenerative acid
b) Deoxyribonucleic acid
c) Deadly nucleic acid
d) Disoriented acid
Answer: b
Clarification: DNA stands for deoxyribonucleic acid. It is a genetic material known for the majority of organisms living on this planet. This substance is responsible for controlling the inheritance of traits.

4. How many types of nucleic acids are present in the living systems?
a) One
b) Two
c) Three
d) Four
Answer: b
Clarification: There are two types of nucleic acids present in our living system. These two are:
i. DNA-deoxyribonucleic acid
ii. RNA-ribonucleic acid
They both can express their effects through the formation and functioning of the traits.

5. DNA is the genetic material in all the known viruses.
a) False
b) True
Answer: a
Clarification: No, DNA is not the genetic material in all the known viruses. It is the genetic material in all organisms except for some viruses, where RNA is the major genetic material like the riboviruses.

6. Which of the following is not a function of RNA?
a) Messenger
b) Catalysis
c) Adapter
d) Modifier
Answer: d
Clarification: RNA does not behave as a modifier. Instead, it functions as a messenger that carries genetic information. It also acts as an adapter for picking up amino acids and in some cases behaves as a catalytic molecule.

7. Which of the following is not a correct statement with respect to DNA?
a) It is a long polymer
b) It is found in the nucleus
c) It is a basic substance
d) First identified by Friedrich Meischer
Answer: c
Clarification: DNA is not a basic substance. Instead, it is an acidic substance. It was first identified by Friedrich Meischer in 1869. It is also known as a long polymer of deoxyribonucleotides and is found in the nucleus of the cell.

8. Which of the following is the characteristic feature of an organism?
a) Number of RNA
b) Number of protein molecules
c) Length of chromosomes
d) Length of DNA
Answer: d
Clarification: The characteristic feature of an organism is the length of its DNA. The length of the DNA is usually defined as the number of nucleotides or the number of base pairs present in it. As this substance was acidic in nature, Altmann named it as a nucleic acid.

9. How many base pairs are present in Escherichia coli?
a) 9856 bases
b) 4.6 x 10⁶ bp
c) 3.3 x 10⁹ bp
d) 10,000 bases
Answer: b
Clarification: The number of base pairs or the number of nucleotides present in the bacterium, Escherichia coli are 4.6 x 10⁶ base pairs. The number of base pairs present in human beings is 3.3 x 10⁹.

10. How many numbers of nucleotides are present in Lambda phage?
a) 48502 bp
b) 98526 bp
c) 10000 bp
d) 5326 bp
Answer: a
Clarification: The number of nucleotides or the number of bases in Lambda phage are 48502. The genetic material of Lambda phage consists of a double-stranded DNA which is linear in shape.

11. Which of the following is correct with respect to the genetic material of Φ174 bacteriophage?
a) ss DNA, linear
b) ss RNA, linear
c) ss DNA, circular
d) ds DNA, linear
Answer: c
Clarification: The genetic material of Φ174 bacteriophage is single-stranded DNA which is circular in shape. It has 5386 bases or a number of nucleotides. It is a virus that attacks on bacteria.

12. The genetic material of humans is double-stranded DNA which is circular in shape.
a) False
b) True
Answer: a
Clarification: The genetic material of humans consists of a double-stranded DNA which is linear in shape. The genetic material of the bacterium Escherichia coli is a double-stranded DNA that is circular in shape.

13. How many components are present in the basic unit of DNA?
a) One
b) Two
c) Three
d) Four
Answer: c
Clarification: There are three components in the basic unit of DNA which is also known as a nucleotide, and they are:
i. A nitrogenous base: purine or pyrimidine
ii. A pentose sugar: Deoxyribose sugar
iii. Phosphate group.

14. Which of the following statements is correct with respect to purines?
a) Purines are heterocyclic compounds
b) Purines are 7 membered structure
c) Purines are single-ring structure
d) Thymine is an example of purine
Answer: a
Clarification: Purines are a type of nitrogenous bases which are heterocyclic compounds. They are 9 membered and are double-ring structures. Nitrogen is present at the positions-1, 3, 7 and 9 of the ring. Adenine and guanine are the only two examples of purines.

15. Which of the following statement is incorrect with respect to pyrimidines?
a) Heterocyclic
b) 7 membered ring
c) Cytosine is an example of pyrimidine
d) Single-ring structure
Answer: b
Clarification: Pyrimidines are not 7 membered rings. Pyrimidines are a type of nitrogenous bases which are heterocyclic compounds with a 6 membered single-ring structure. Nitrogen is present at 1 and 3 positions of the rings. Examples of pyrimidines include thymine, uracil, and cytosine.

16. By which of the following bonds, a nitrogenous base is linked to the pentose sugar?
a) Phosphate bond
b) Ester bond
c) Peptide bond
d) N-glycosidic bond
Answer: d
Clarification: A nitrogenous base is linked to the pentose sugar by an N-glycosidic bond. As a result of this linkage, a nucleoside is formed. Purine nucleosides have 1’-9 glycosidic linkage and pyrimidine nucleosides have 1’-1 linkage.

Biology online quiz on “Hardy-Weinberg Principle-2”.

1. Which of the following does not belong to the Hardy Weinberg principle?
a) Frequency remained fixed through generations
b) Used algebraic equations
c) Allele frequency varies from species
d) Gene pool remains a constant
Answer: c
Clarification: Allele frequencies does not vary from species to species. In a population, the frequency always remains fixed or constant according to Hardy Weinberg principle. The alleles and total genes in any population remain constant and hence stable.

2. It is known that the total sum of all the frequencies of the allele is _____
a) one
b) two
c) three
d) four
Answer: a
Clarification: According to Hardy Weinberg principle, the total sum of all the frequencies of the allele is one. It shows that the gene pool remains the same or constant, i.e. one. Hence, it can be also termed as genetic equilibrium.

3. Which of the following represents the Hardy Weinberg equation?
a) p² + q² = 1
b) p² + 2pq + q² = 1
c) p² + q² = 0
d) (p² + q²)² = 1
Answer: b
Clarification: The Hardy Weinberg equation is p² + 2pq + q² = 1. Here, p² denotes the allele of AA and q² denotes the allele aa. This shows that p, q, and A, a are related in multiplication. So, 2pq represent Aa.

4. The notation p and q of the Hardy Weinberg equation represent ________ of a diploid organism.
a) frequency of allele p
b) frequency of only allele A
c) frequency of the only allele a
d) frequency of allele A and a
Answer: d
Clarification: Individual frequencies can be represented as p and q. But for a diploid organism, p and q explain the frequency of allele A and allele a. p² represents AA whereas q² represent aa.

5. The difference in frequency indicates the extent of evolutionary change.
a) True
b) False
Answer: a
Clarification: It is a correct statement as allele frequency is the main trigger to evolution. When the frequency changes in a population either due to migration or other factors, this results in evolutionary change.

6. How many factors affect the Hardy Weinberg principle?
a) Six
b) Four
c) Seven
d) Five
Answer: d
Clarification: Hardy Weinberg stated that there are six factors affecting this principle. They are Gene migration or gene flow, genetic drift, mutation, genetic recombination, and natural selection. Each factor plays a major role in evolution.

7. Which of the following does not belong to factors affecting the Hardy Weinberg principle?
a) Gene migration
b) Genetic drift
c) Genetic drop
d) Mutation
Answer: c
Clarification: There are six factors affecting this principle. Among the factors, the genetic drop is not included in them. They only include Gene migration or gene flow, genetic drift, mutation, genetic recombination, and natural selection.

8. The process when some species migrate from the original to a new place, which in turn changes the allele frequency is called ______
a) Gene drift
b) Gene migration
c) Gene travel
d) Genetic recombination
Answer: b
Clarification: Gene migration or gene flow occurs when some species migrate from original to a new place. This changes the allele frequency in the old as well as a new place. So, new genes or alleles are being added to the new population and removed from the old one.

9. Gene drift occurs when gene migration occurs ______
a) by chance
b) spontaneously
c) slowly
d) due to disaster
Answer: a
Clarification: Gene flow occurs when gene migration occurs many or multiple times. When this occurs by a chance, a process called gene drift occurs. It cannot occur spontaneously, slowly or due to a disaster.

10. Which is the correct statement regarding Founder effect?
a) Named after the scientist John Founder
b) No large change in frequency
c) The old population become founders
d) Formation of new species
Answer: d
Clarification: Some species travel to new places. This changes the allele frequency totally and makes them different species. So, the original species that migrated become founders. Hence the name Founder effect.

11. What results in the formation of new phenotypes?
a) Pre-existing helpful mutations
b) Post-existing helpful mutations
c) Pre-existing disadvantageous mutations
d) Post-existing advantageous mutations
Answer: a
Clarification: According to microbial experiments, pre-existing helpful of advantageous mutations results in the formation of new phenotypes. This finally results in a process called Speciation. Mutation also has a relation with creating new phenotypes.

To practice all areas of Biology for online Quizzes,

Biology Online Quiz for NEET Exam on “Helminthic Diseases in Humans-2”.

1. Roundworm infection produces ________
a) Vague symptoms of nausea and cough
b) Clear Symptoms of abdominal pain and obstruction
c) Internal Bleeding, Pneumonia and Peritonitis in all cases
d) Eosinophilia never occurs
Answer: a
Clarification: Roundworm infection initially causes vague symptoms of nausea and cough. Later on, anaemia, weakness, muscular pain and fever begins to appear. Eosinophilia also occurs. Intestinal pain and diarrhoea may also occur. If brain and liver are damaged by the juvenile worms, then internal bleeding, pneumonia and peritonitis occur.

2. Which of the following is the smallest tapeworm?
a) Dipylidium caninum
b) Hymenolepis nana
c) Taenia asiatica
d) Echinococcus granulosus
Answer: d
Clarification: Echinococcus granulosus is the smallest tapeworm. It is an endoparasite in dogs, cats, fox and other carnivores. It has well-developed scolex with four suckers and rostellum with a double row of hooks.

3. Which of the following tapeworm is commonly called as Pork tapeworm?
a) Taenia saginata
b) Taenia solium
c) Echinococcus granulosus
d) Diphyllobothrium latum
Answer: b
Clarification: Taenia solium is commonly called as the Pork tapeworm. Its primary host is a man and its secondary host is a pig. Taenia saginata, Echinococcus granulosus and Diphyllobothrium latum are commonly known as Beef tapeworm, Dog tapeworm and Fish tapeworm respectively.

4. The common roundworm infecting human beings is _______
a) Ascaris lumbricoides
b) Taenia solium
c) Fasciola hepatica
d) Enterobius histolytica
Answer: a
Clarification: The common roundworm infecting human beings is Ascaris lumbricoides. The parasite is monogenetic which means that only one host is required for its development. Life span is nine to twelve months. It is common in children than in adults.

5. The infective stage of Ascaris lumbricoides is _________
a) First stage Rhabditiform larva
b) Second stage Rhabditiform larva
c) Third stage Rhabditiform larva
d) Fourth stage Rhabditiform larva
Answer: b
Clarification: Second stage Rhabditiform larva is the infective stage of Ascaris lumbricoides. Infective eggs of Ascaris remain viable for six years. The larva is called Rhabditiform for its close resemblance with Rhabditis (Free-living nematode). The transmission of the infective stage through embryonated egg takes place by contaminated food and water.

6. Which of the following pathogen is not responsible for causing Filariasis?
a) Wuchereria bancofti
b) Brugia malayi
c) Schistosoma haematobium
d) Brugia timori
Answer: c
Clarification: Filariasis is due to a nematode Wuchereria bancofti. Other species are Brugia malayi and Brugia timori. The diseases spread by them are respectively called as bancroftian filariasis and burgian filariasis.

7. The infection of Onchosphere larva to man leads to ___________
a) Dracunculiasis
b) Ancylostomiasis
c) Enterobiasis
d) Cysticercosis
Answer: d
Clarification: The infection of Onchosphere larva to man leads to Cysticercosis. Through blood, it spreads to the brain and spinal cord. It can cause seizures, severe headache, epilepsy or even blindness.

8. Which of the following is the larva of Culex which causes Filariasis?
a) Filariform larva
b) Microfilaria larva
c) Trichinella larva
d) Dracunculus larva
Answer: b
Clarification: In the salivary glands of Culex, microfilaria larva is present. When Culex bites a person, this larva reaches the lymphatic system changing into adult forms. At night, larva reaches into the blood and in the day, it reaches the lymphatic vessels. Therefore, the night blood examination can reveal the parasite.

9. Which of the following larva forms of Fasciola hepatica cause polyembryony?
a) Miracidium and Sporocyst larva
b) Cercaria and Metacercaria larva
c) Sporocyst and Rediae larva
d) Metacercaria and Rediae larva
Answer: c
Clarification: Sporocyst and Rediae larva of Fasciola hepatica show Polyembryony. As Germ Cells in the Sporocysts and Rediae are direct descendants of the zygote. These germ cells multiply mitotically and produce subsequent larval stages within the Sporocysts and Rediae. This process of reproduction in the Sporocyst and Rediae is called as Polyembryony.

10. Which Helminthic disease is most common in children?
a) Enterobiasis
b) Ancylostomiasis
c) Loiasis
d) Filariasis
Answer: a
Clarification: Enterobiasis is the most common Helminthic disease in children. It is the infection of Large Intestine. It is caused by Enterobius vermicularis which is also known as Pinworm.

11. Anal itching is the characteristic symptom of _________
a) Ancylostomiasis
b) Enterobiasis
c) Trichinosis
d) Trichuriasis
Answer: b
Clarification: Anal itching is the characteristic symptom of Enterobiasis. The female worm lays eggs in the peri-anal region. Other symptoms include loss of appetite, insomnia, restlessness, abdominal pain and appendicitis.

12. Primary host and secondary host of Wuchereria are ___________
a) Human and Cow
b) Human and Elephant
c) Human and Culex mosquito
d) Human and Anopheles mosquito
Answer: c
Clarification: Wuchereria bancofti causes Elephantiasis. It shows a digenetic life cycle which means that the parasite completes its life cycle in two or more hosts. Its primary host is Human and Secondary host is Vector Female Culex mosquito.

To practice Biology Online Quiz for NEET Exam,

Biology Multiple Choice Questions on “Human Health and Disease – Types of Cancer”.

1. Which of the following is the most common form of cancer?
a) Carcinoma
b) Sarcoma
c) Melanoma
d) Lymphoma
Answer: a
Clarification: Carcinoma is the most common form of cancer. It is a cancer of epithelial tissues and their derivatives like skin, mucous membrane, lungs, breast, pancreas, stomach etc.

2. Which of the following cancers is derived from mesodermal tissues?
a) Carcinoma
b) Leukaemia
c) Breast Cancer
d) Sarcoma
Answer: d
Clarification: Sarcoma is the cancer of primitive mesodermal tissue like connective tissue, bone, muscle, lymph nodes, etc. The occurrence of these types of cancer is very rare.

3. In which of the following cancers, there is a tremendous increase in the number of WBCs?
a) Leukaemia
b) Sarcoma
c) Melanoma
d) Carcinoma
Answer: a
Clarification: Leukaemia is a malignancy where there is an unwanted and uncontrolled increase in White blood corpuscles and immature or myeloid stem cells. These WBCs infiltrate the bone marrow, liver, spleen, lymph nodes and other organs causing damage and increase in their size.

4. Which of the following cancers does not come under the category of Sarcoma?
a) Lymphoma
b) Adenoma
c) Myelocytic Leukaemia
d) Angiosarcoma
Answer: c
Clarification: Sarcoma is the cancer of organs derived from mesoderm. Depending upon the tissue involved, sarcoma is of several types, e.g., lymphoma (involving lymph vessels), lipoma (Adipose tissue), malignant reticulosis, angiosarcoma (blood vessels) etc.

5. Which of the following cancers is commonly known as Bone Cancer?
a) Melanoma
b) Adenoma
c) Lymphoma
d) Osteoma
Answer: d
Clarification: Osteoma is commonly called as Bone Cancer. It is a type of sarcoma where some cells undergo uncontrolled division and form a small mass of cells over the bone. These small mass of cells may even replace the healthy bone tissue.

6. Which of the following chromosomes are involved in myelocytic leukaemia?
a) 7^th and 20^th
b) 9^th and 22^nd
c) 1^st and 2^nd
d) 3^rd and 4^th
Answer: b
Clarification: In myelocytic leukaemia, 9^th and 22^nd chromosomes bring their jumping genes together which results in the rearrangement of genetic material between them. It leads to the degeneration of erythroblastic tissue of bone marrow. There is bleeding at different places in the body.

7. The most common form of cancer that affects Indian men is ____________
a) mouth and throat cancer
b) lung cancer
c) pancreatic cancer
d) bone cancer
Answer: a
Clarification: The most common form of cancer that affects Indian men is Mouth and Throat Cancer. India has one-third of Mouth and Throat Cancer cases in the world. Oral or Mouth Cancer accounts for about 30% of all cancers in India.

8. Breast Cancer is a type of Sarcoma.
a) True
b) False
Answer: b
Clarification: Breast Cancer is a type of Carcinoma where there is an abnormal and uncontrolled division of cells in the breast. Its symptoms include a lump in the breast, mucous or bloody discharge from the lumps or from the nipples.

9. The following diagram is a representation of __________

a) Blood Vessels
b) Lymph nodes
c) Blood Route
d) Various Organs of the body
Answer: b
Clarification: The given diagram is a representation of Lymph nodes. The lymph nodes are small solid structures located at different points along with the lymphatic system. They serve to trap the micro-organisms or other antigens, which happen to get into the lymph and tissue fluid.

10. Pituitary Cancer is a type of ___________
a) Carcinoma
b) Leukaemia
c) Lymphoma
d) Adenoma
Answer: d
Clarification: Pituitary Cancer is a type of Adenoma. It is cancer caused by the excessive growth of glandular epithelium. Symptoms include irregular menstruation, vision disorders, headache etc.

11. Which of the following is the cancer of Glial cells of CNS?
a) Melanoma
b) Glioma
c) Adenoma
d) Lymphoma
Answer: b
Clarification: Glioma is the cancer of Glial cells of CNS. Melanoma, Adenoma and Lymphoma are the cancers of pigment cells of the skin, glands and lymphatic tissue respectively.

12. Which of the following are the most common forms of cancers in Indian women?
a) Breast and Cervical Cancer
b) Thyroid Cancer
c) Lung Cancer
d) Oral Cancer
Answer: a
Clarification: The most common form of cancer in Indian females is Breast and Cervical cancer. One woman dies of cervical cancer every 8 minutes in India. For every 2 women newly diagnosed with breast cancer, one woman dies of it in India.

13. Leukaemia is a type of non-tumorous cancer.
a) True
b) False
Answer: a
Clarification: Leukaemia is a cancer of the blood or bone marrow. It is non-tumorous cancer which is caused by the uncontrolled division of blood cells. They get accumulated in the bloodstream and thus occupy more space and hence stop the white blood cells from functioning normally.

14. Which of the following is not a symptom of Lymphoma?
a) Swollen Lymph Nodes
b) Weight Loss
c) Euphoria
d) Fatigue
Answer: c
Clarification: Lymphoma is the cancer of lymphoid tissue which can occur in lymph nodes, spleen, thymus, bone marrow and other lymphoid structures. Its symptoms include Swollen lymph nodes, Weight Loss, fatigue, Breathlessness, loss of appetite etc.

15. The vagina is a target tissue for which of the following chemical carcinogens?
a) Asbestos
b) Soot
c) Diethylstilboestrol (DES)
d) Cadmium Oxide
Answer: c
Clarification: Vagina is the target tissue for Diethylstilboestrol (DES). Asbestos, Soot and Cadmium Oxide are the chemical carcinogens for Lungs, Skin and Prostate gland respectively.

Biology Multiple Choice Questions on “Food Production Strategies – Sericulture”.

1. What is sericulture?
a) Rearing of fishes
b) Rearing of silkworm
c) Rearing of birds
d) Rearing of cockroach
Answer: b
Clarification: Sericulture is the breeding and management of insects for the production of silk. Silk is of two main types-mulberry silk or cultivated silk and non-mulberry silk or wild silk.

2. Which of the following varieties of silk is not produced in India?
a) Muga Silk
b) Mulberry Silk
c) Tassar Silk
d) American Silk
Answer: d
Clarification: Four varieties of silk produced in India are natural silk, mulberry, tassar, eri and muga. India ranks third among the mulberry silk-producing countries of the world.

3. Which of the following is not considered as a silk city of India?
a) Jaipur
b) Kanchipuram
c) Bhagalpur
d) Pochampally
Answer: c
Clarification: India’s silk industry is the world’s second-largest contributor to 18% of the total raw silk production. The cities contributing for such growth of silk are Kanchipuram in Tamil Nadu, Bhagalpur in Bihar, Pochampally in Telangana. They are called silk cities in their respective states.

4. Which of the following is not the characteristic feature of Tassar silk?
a) Also known as Kosa silk
b) Obtained from Bombyx mori
c) A native of India and China
d) Larvae of the silkworm feed on oak
Answer: b
Clarification: Tassar silk is also known as Kosa silk. It is obtained from the oak-feeding larvae of the silk moth-Antheraea mylitta. It is a native of India and China. Tassar cocoons are attached by a peduncle to twigs of Sal trees.

5. Which of the following silk is mainly produced in Assam?
a) Arundi silk
b) Natural silk
c) Muga silk
d) Tassar silk
Answer: c
Clarification: Muga silk is produced by the larva of Antheraea assamensis in Assam. It is golden yellow in colour and superior to tassar silk in gloss and other qualities. It is an excellent material for embroidery.

6. Which of the following is not a characteristic feature of Eri silk?
a) Also known as Arundi silk
b) Produced in Bengal, Bihar and Assam
c) Cocoons are soft and white
d) Larva feeds on oak leaves
Answer: d
Clarification: Eri or Arundi silk is produced by the larva of Philosamia ricini and is made in Bengal, Bihar and Assam. The eri silkworms feed on castor leaves and are reared indoors. The cocoons are soft and white or yellowish.

7. How many stages are there in the life cycle of a silkworm?
a) 3
b) 4
c) 5
d) 6
Answer: b
Clarification: The life history of silk moth passes through four stages-egg, larva, pupa and adult. About 50% of the cocoon are kept in boiling water to kill pupa and then thread is reeled off. Rest 50% are kept as such so that they become adult and the life cycle starts once again.

8. Cocoon is formed by how many pairs of glands?
a) Two
b) Three
c) Four
d) One
Answer: a
Clarification: The cocoon is formed by two pairs of glands. One pair of glands form a protein fibroin which forms twin filaments and other pair of glands form a protein sericin which is responsible for joining of twin filaments.

9. Raw silk is prepared by degumming.
a) True
b) False
Answer: b
Clarification: Silk containing sericin is called as raw silk. Sericin is a gummy substance which is usually retained as it gives protection to silk during processing. So in order to obtain Pure silk, sericin is chemically removed. This makes the silk soft and also reduces its weight.

10. Which of the following state is not a mulberry silk manufacturer in India?
a) Assam
b) Karnataka
c) Andhra Pradesh
d) Tamil Nadu
Answer: a
Clarification: In India, 97% of the raw mulberry silk is produced in Karnataka, Andhra Pradesh, Jammu and Kashmir, Tamil Nadu and West Bengal. The non-mulberry silk industry is found in Assam, Bihar, Bengal, Odisha and Madhya Pradesh. There are three main types of silk- Tassar silk, Muga silk and Eri silk.

11. Pebrine disease in silkworms is caused by a fungus.
a) True
b) False
Answer: b
Clarification: Pebrine disease of silkworms is caused by a protozoan Nosema bombycis. Fungus Spicaria and Botrytis cause Muscardine. Flacherie disease of silkworms is caused by a virus.

Biology Question Papers for Schools on “Microbes in Household Products-2”.

1. Which of the following is not a type of cheese?
a) Cottage
b) Tempeh
c) Roquefort
d) Camembert
Answer: b
Clarification: Cheese is pressed and flavoured milk curd and more than 2000 varieties of cheese are known. Some of the types include Raw cheese, cottage cheese, Swiss cheese, camembert cheese, Roquefort cheese, etc.

2. Which of the following statements is not related to cottage cheese?
a) Ripened soft cheese
b) Prepared by inoculating skimmed milk first
c) Rennin or chymosin are added
d) Cheese culture of Streptococcus lactis is used
Answer: a
Clarification: Cottage milk cheese is an unripened soft cheese which is prepared by inoculating skimmed milk first with cheese culture of Streptococcus lactis and then rennin or chymosin which is obtained from a fungus source.

3. Which of the following is not a type of ripened cheese?
a) Soft cheese
b) Semi-soft cheese
c) Hard cheese
d) Unbreakable cheese
Answer: d
Clarification: Ripening of cheese is carried out to provide cheese with a characteristic texture, flavour and taste. There are three types of ripened cheese- soft cheese, semi-soft cheese and hard cheese.

4. Moisture content in soft cheese is about 75 per cent.
a) True
b) False
Answer: b
Clarification: Moisture content in soft cheese is about 50 per cent, e.g., Camembert cheese, in semi-soft cheese is about 45 per cent, e.g., Roquefort cheese and hard cheese is about 40 per cent, e.g., Cheddar cheese.

5. Which of the following helps in the ripening of Camembert cheese?
a) Penicillium roquefortii
b) Propionibacterium sharmani
c) Penicillium camembertii
d) Leuconostoc citrovorum
Answer: c
Clarification: Ripening of cheese is carried out with the help of specific microbes. For example, Camembert cheese is ripened with the help of Penicillium camembertii. Roquefort cheese and Swiss cheese are ripened with the help of Penicillium roquefortii and Propionibacterium sharmani respectively.

6. Which of the following statements is incorrect regarding sausages?
a) These are fermented meats
b) Their taste depends upon the fermenting agent
c) The lactic acid bacterium is the least favoured bacterium
d) Lactic acid bacterium preserves sausages
Answer: c
Clarification: Sausages are fermented meats which possess particular flavour and its taste depends upon the fermenting agent. The most commonly employed microbe is a lactic acid bacterium. The bacterium also preserves the sausages.

7. The LAB plays no role in the stomach.
a) True
b) False
Answer: b
Clarification: A small amount of curd added to the fresh milk as inoculum contains millions of LAB, which at suitable temperatures multiply, thus converting milk to curd, which also improves its nutritional quality by increasing Vitamin B12. In our stomach too, the LAB plays a very beneficial role in checking the disease-causing microbes.

8. Which of the following statements is not related to toddy?
a) Prepared by fermentation of coconut water
b) Traditional drink in some parts of Northern India
c) Jaggery is produced by boiling it
d) Arrack is obtained from toddy
Answer: b
Clarification: Coconut water is fermented to produce a refreshing drink called toddy. It is a traditional drink in some parts of Southern India. Palm sugar or jaggery is produced by boiling it. Arrack is obtained by the distillation of fermented toddy.

9. Who discovered pasteurisation?
a) Arthur Eddington
b) Ernst Haeckel
c) Carl Woese
d) Pasteur
Answer: d
Clarification: In 1864, Pasteur discovered the process of pasteurisation. It is a process of preservation of milk, wine and other liquids by heating for a short period and then cooling suddenly. This kills most of the microbes.

10. Which of the following is also known as Single Cell Protein?
a) Probiotics
b) Antibiotics
c) Multibiotics
d) Synbiotics
Answer: a
Clarification: Live microbial food is called as probiotics, therefore single-cell protein is also referred to as probiotics. It is protein-rich microbial biomass which can be used as food and feed.

11. Which of the following statement is the only correct statement regarding single-cell protein?
a) SCP has all the non-essential amino acids
b) Only autotrophs are used as SCP
c) Fat content is high
d) The protein content is high
Answer: d
Clarification: SCP has all the essential amino acids. Both autotrophs and heterotrophs are used as SCP. SCP is low in fat content and high in protein content.

12. Which of the following is used amongst heterotrophs as SCP?
a) Protozoa
b) Aspergillus
c) Yeast
d) Spirulina
Answer: c
Clarification: Amongst heterotrophs, yeast and mushrooms are being raised as SCP. There is increasing use of low-cost organic matter for raising SCP like filamentous fungus and common mushrooms.

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