Category: Class 12 Biology Objective Questions

Biology Objective Questions & Answers on “Evolution – Origin of Life – 2”.

1. What is most important element for origin of life?
a) Water
b) Oxygen
c) Carbon
d) Nitrogen
Answer: a
Clarification: Water is essential for origin of life, since first life originated in the water of oceans. After a long time, the water of primitive oceans had rich mixtures of organic compounds. This produced a platform for origin of life.

2. The theory of spontaneous generation was rejected by which scientist?
a) Pasteur
b) Lavoisier
c) Kuhn
d) Lamarck
Answer: a
Clarification: Pasteur is very famous for his Germ Theory. This theory disproved spontaneous generation, as he had done an experiment to prove that life came from pre-existing cells.

3. Which among the compounds were formed during the origin of life?
a) Urea, amino acid
b) Urea, nucleic acid
c) Proteins, nucleic acid
d) Proteins, amino acid
Answer: c
Clarification: Proteins, nucleic acid were the main two compounds formed during origin of life. Experiments done by many scientists also resulted to creation of proteins and nucleic acid. This shows that these compounds existed during origin of life.

4. The name of the theory given by Louis Pasteur was called as _______
a) Cellular theory
b) Recapitulation theory
c) Germ theory of disease
d) Pasteurization
Answer: c
Clarification: Louis Pasteur found the Germ theory of diseases or Germ theory. He stated that life did not come from killed yeast in pre-sterilized flask. Whereas the flask opened to air, the new organisms arose from the killed yeast.

5. Life originated on earth about _____
a) 8 billion years ago
b) 5 billion years ago
c) 4 billion years ago
d) 3 billion years ago
Answer: c
Clarification: Life originated on earth about 4 billion years ago. That is life appeared 500 million years after the formation of earth. First non-cellular forms of life originated 3 billion years ago.

6. What did Stanley Miller synthesize in his evolution experiment?
a) Virus
b) Protein
c) Cell
d) Amino acid
Answer: d
Clarification: Miller created a closed flask containing an electric discharge along with gases maintained at 800°C. It resulted in the formation of amino acids. They had similarity with meteorite content which indicated that life came from outer space.

7. Nucleoproteins were the first substance to give sign of ______
a) Species
b) Evolution
c) Life
d) Genes
Answer: c
Clarification: Nucleoproteins are complex structured compounds which bonding between a nucleic acid and a protein. Nucleoproteins were the first compound to give sign of life. It had the property of self-duplication.

8. Life first originated in ______
a) Earth
b) Air
c) Water
d) Soil
Answer: c
Clarification: Life first originated in water. Whether cellular or acellular, life started in water environment only, millions of years ago. Water was formed from the reaction of active hydrogen and free oxygen atoms.

9. Miller and Urey had performed an experiment to prove the origin of life. They took gases H₂0 and CH₄ along with _______
a) N₂ and H₂O
b) NH₃ and H₂
c) CH₄ and N₂
d) CO₂ and NH₃
Answer: b
Clarification: Miller took a mixture of water, methane, ammonia and hydrogen in a closed flask at 800°C. It was done in a closed flask and using electric discharge tubes, and later observed the formation of amino acids.

10. It is due to the phenomenon Big bang; the origin of life took place.
a) True
b) False
Answer: b
Clarification: Universe was created due to Big bang theory and not life. Life originated about 4 billion years ago whereas the Big bang took place about 20 million years back.

11. At what temperature was the flask maintained in Miller’s experiment?
a) 900°C
b) 800°C
c) 700°C
d) 600°C
Answer: b
Clarification: It was at 800°C in which the flask was maintained along with electric discharge. A moderately high temperature was required to keep the flask sterilized. Thus, creating amino acids as the product.

To practice all objective questions on Biology,

Biology Written Test Questions for Pharmacy Entrance Exams on “Origin and Evolution of Man – 5”.

1. Which of the following does not belong to Peking man’s characteristics?
a) Origin and evolution before 6 lakh years
b) They lived in huts
c) Cranial capacity was 850-1300 c.c.
d) Complete erect posture
Answer: b
Clarification: Peking man lived in caves and not in huts. They were not civilized like modern man. The remaining options are the characteristics of Peking man.

2. Who discovered the fossil of Heidelberg man?
a) Ottoschotensack
b) Habbertensack
c) Fulhrott
d) Heidelinsack
Answer: a
Clarification: The fossil was discovered by Ottoschotensack. He found a fossil of the lower jaw from Heidelberg in Germany. They evolved during the Pleistocene epoch.

3. Which of the following does not belong to Homo sapiens?
a) Neanderthal man
b) Cromagnon man
c) Modern man
d) Peking man
Answer: d
Clarification: Peking man belongs to Homo erectus and not Homo sapiens. Homo sapiens consist of Neanderthal man, Cromagnon man, and Modern man. Modern man refers to Homo sapiens sapiens.

4. Who is known as the direct ancestor of modern man?
a) Cromagnon man
b) Java man
c) Heidelberg man
d) Neanderthal man
Answer: a
Clarification: Cromagnon man is known as the direct ancestor of modern man. Their scientific name is Homo sapiens fossilis. Fossils were discovered by Mac Gregor from Cromagnon rocks of France.

5. Ceremonial burial of dead body was started by _________
a) Neanderthal man
b) Modern man
c) Java man
d) Handy man
Answer: a
Clarification: The ceremonial burial of the dead body was started by Neanderthal man. The dead body was buried along with flowers and tools. They were the first ones believe in the immortality of the soul.

6. Which is the correct statement of Neanderthal man?
a) They lived in caves
b) Cranial capacity was 1000-1300 c.c.
c) They wore clothes of animal skin
d) High developed chin
Answer: c
Clarification: They lived in huts. They had a cranial capacity of 1300-1600 c.c. and a less developed chin. They had a complete erect posture. Also, they had a semicircular jaw and was orthognathous.

7. The scientific name of Cromagnon man is ______
a) homo sapiens sapiens
b) homo sapiens fossilis
c) homo sapiens neanderthalensis
d) homo sapiens pekinensis
Answer: b
Clarification: The scientific name of Cromagnon man is Homo sapiens fossilis. They evolved around 50,000 to 10,000 years ago and discovered from Cromagnon rocks. They were the direct ancestor of modern man.

8. Who started the domestication of animals?
a) Java man
b) Neanderthal man
c) Heidelberg man
d) Cromagnon man
Answer: d
Clarification: Homo sapiens fossilis also known as Cromagnon man started the domestication of animals. This man was a hunter and used domesticated dogs in hunting. Also, they used to wear cloth of animal skin. By nature, they were carnivorous.

9. Prehistoric cave art developed about 10,000 years ago.
a) True
b) False
Answer: b
Clarification: It is a wrong statement as prehistoric cave art developed about 18,000 years ago. It was one of the special features of the Cromagnon man. They painted beautiful paintings on cave walls.

10. The cranial capacity of Modern man was ______ c.c.
a) 1300-1600
b) 1000-1100
c) 850-1300
d) 1300
Answer: a
Clarification: The cranial capacity of Modern man is the same as that of Neanderthal man i.e. 1300-1600 c.c. They had a fully developed brain. Heidelberg man had a cranial capacity of only 1300 c.c. whereas Peking man had ranged from 850-1300 c.c.

11. Cromagnon man had higher cranial capacity than Modern man.
a) True
b) False
Answer: a
Clarification: Cromagnon man had maximum cranial capacity about 1650 whereas Modern man had only 1300-1600 c.c. This shows that the cranial capacity reduced after the evolution of Cromagnon man. The size of the skull also reduced to a more humanoid one.

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Biology Multiple Choice Questions on “Human Health and Disease – Cell Mediated Immunity”.

1. The full form of CMI is __________
a) cell Medium Immunoglobulin
b) cell-Mediated Immunity
c) cyst Marked Infection
d) cellular Medium Infection
Answer: b
Clarification: The full form of CMI is Cell-Mediated Immunity. The immune system comprises of T- lymphocytes that defend the body against pathogens, cancers and foreign structures like tissue transplants.

2. Which of the following mediate the CMI?
a) T-lymphocytes
b) Red blood corpuscles
c) White Blood cells
d) B-lymphocytes
Answer: a
Clarification: T-lymphocytes mediate CMI. T-cells/T-lymphocytes are long-lived small cells which have 100,000 receptor sites on their surface for binding antigens. T-cells themselves do not secrete antibodies but help B-cells to produce them.

3. Which of the following is called as Competent lymphocytes?
a) B-lymphocytes
b) T-lymphocytes
c) C- lymphocytes
d) S-lymphocytes
Answer: b
Clarification: T-lymphocytes are called as Competent lymphocytes. The cells develop antigen specificity through the previous contact. T-lymphocytes respond to specific antigen by forming a clone of cells.

4. Number of lymphocytes present in a healthy human is ___________
a) 1 trillion
b) 1 million
c) 1 billion
d) 10 trillion
Answer: a
Clarification: Number of lymphocytes present in a healthy human is 1 trillion. Unusually high or low lymphocyte counts can be a sign of disease.

5. A person without thymus would not be able to reject a tissue transplant.
a) True
b) False
Answer: a
Clarification: Thymus is a lobed organ located near the heart and beneath the breast bone. It is the site where T-lymphocytes mature. T-cells are the specialized white blood cells which help to defend the body.

6. What is the life of the effector cells of the immune system?
a) A few weeks
b) A few days
c) A few months
d) A few years
Answer: b
Clarification: The life span of effector cells of the immune system is a few days only. Our body releases two types of cells-effector cells and memory cells, of which, effector cells are short-lived and are responsible for the primary response of our body.

7. Which of the following sets include all the types of T-cells?
a) Killer cells and Helper cells
b) Suppressor and Cytotoxic cells
c) Depressor cells, Helper cells and Memory cells
d) Killer cells, Helper cells, Suppressor cells and Memory cells.
Answer: d
Clarification: T-cells of our immune system gets differentiated into Killer or cytotoxic cells, Helper cells, Suppressor cells and Memory cells. Killer, Helper and Suppressor T-cells are also called as Effector cells.

8. Life span of T-cells __________
a) 4-5 hours
b) 4-5 days
c) 4-5 weeks
d) 4-5 years
Answer: d
Clarification: Life span of T-cells is around 4-5 years. The T-cells produced are relatively long-lived to compensate the less number of T-cells produced by thymus in the later years.

9. B-cells produce antibodies in response to the instruction received from _________
a) Killer T-cells
b) Suppressor T-cells
c) Memory Cells
d) Helper T-cells
Answer: d
Clarification: B-cells produce antibodies in response to the instruction received from Helper T-cells. Along with this, Helper T-cells also attract macrophages to the site of infection.

10. How can Organ transplantation rejection be prevented?
a) Immunosuppressant drugs
b) Depressant drugs
c) Interferons
d) New T-cells
Answer: a
Clarification: Our body produces a certain type of antibodies in response to the antigens. When an organ is transplanted, the body recognises the ‘non-self’ cells and starts attacking them. Therefore, Organ Transplantation rejection can be prevented by giving Immunosuppressant drugs so that the immune system gets suppressed and do not attack the ‘non-self’ cells.

11. Which of the following cells of the immune system are responsible for causing pores in the plasma membrane of antigens?
a) Helper T-cells
b) Killer T-cells
c) Suppressor T-cells
d) Memory cells
Answer: b
Clarification: Killer T-cells are responsible for producing pores in the plasma membrane of the antigens. The interaction of Killer T-cells with antigens will produce perforins to kill the infected cells.

12. What does T stand for in T-lymphocytes?
a) Tonsils
b) Thymus
c) Tissue
d) Thyroid
Answer: b
Clarification: The letter T in T-lymphocytes stands for Thymus. The thymus is a primary lymphoid organ which is responsible for differentiating T-lymphocytes into antigen sensitive lymphocytes.

13. Helper T-cells can be distinguished from killer T-cells by the presence of _________
a) CD-2 receptor
b) CD-3 receptor
c) CD-8 receptor
d) CD-4 receptor
Answer: d
Clarification: Helper T-cells can be distinguished from Killer T-cells by the presence of CD-4 receptor. CD-8 receptors are present in both Killer T-cells and Suppressor T-cells.

14. Which of the following cell surfaces do not have Major Histocompatibility complex?
a) Red Blood Corpuscles
b) White Blood Cells
c) Helper T-cells
d) Killer T-cells
Answer: a
Clarification: The cell surface of Red Blood Corpuscle does not have Major Histocompatibility Complex. This complex is responsible for displaying the peptide fragments of antigens to the appropriate T-cells of our immune system.

15. What is meant by Apoptosis?
a) Accidental Cell Death
b) Programmed Cell death
c) Accidental Cell division
d) Programmed Cell division
Answer: b
Clarification: Apoptosis has been derived from an Ancient Greek word meaning “falling off”. In biology, Apoptosis refers to a form of programmed cell death that occurs in multicellular organisms. It is used by the immune system to get rid of the virus-infected cells.

Biology Aptitude Test for MBBS Entrance Exams on “Human Health and Disease – Drugs and Alcohol Abuse-6”.

1. Which of the following generally does not happen when a combination of drugs is taken?
a) Enhance sedation
b) Causes various complications
c) Reduce the effect of a drug
d) Does not affect the individual
Answer: d
Clarification: There is often a mix up of drugs with alcohol and other substances, For e.g., Insulin, aspirin. So the combination of drugs may enhance sedation, cause complication (e.g., hypertension) or reduce the effect of medicine.

2. Which drug combination causes Dramatic sedative effect?
a) Alcohol + Benzodiazepines
b) Alcohol + Antihistamines
c) Alcohol + Barbiturates
d) Alcohol + Aspirin
Answer: a
Clarification: The combination of Alcohol and Benzodiazepines causes a dramatic sedative effect. The combination of Alcohol with Antihistamines, Barbiturates and Aspirin causes marked drowsiness, marked depressant effect and damage to gastric mucosa respectively.

3. Which drug combination causes decreased insulin effect?
a) Barbiturate + Benzodiazepine
b) Cocaine + antidepressant
c) Cocaine + Nicotine
d) Amphetamine + Insulin
Answer: d
Clarification: The combination of Amphetamine and Insulin causes decreased Insulin effect. The combination of Barbiturate and Benzodiazepine causes increased sedation of those drugs. The combination of Cocaine with antidepressant and nicotine causes hypertension and increased cardiovascular activities respectively.

4. The combination of Alcohol and Cannabis causes damage to the gastric mucosa.
a) True
b) False
Answer: b
Clarification: The combination of Alcohol and Cannabis causes marked loss of body coordination, increased reaction time and impaired judgement. The combination of Alcohol and Aspirin causes damage to the gastric mucosa.

5. Which of the following symptom does not show physical dependence on drugs?
a) Tremors
b) Twitching
c) Craving
d) Convulsions
Answer: c
Clarification: In physical dependence, the repeated use of the drug changes the physical; equilibrium of the body so much that in the absence of the drug, normal functioning of the body is impaired resulting in tremors, cramps, twitching, convulsions, fits, severe agitation which is sometimes even life-threatening.

6. Which of the following is a common characteristic of a psychological dependence on drugs?
a) Craving or overwhelming desire to have drugs
b) Convulsions
c) Fits
d) Spasm
Answer: a
Clarification: In psychological dependence, the drug gives mental satisfaction. Even the smell, sight or thought of the drug brings about craving or overwhelming desire to have the same. Therefore, psychological dependence is difficult to overcome.

7. Which of the following is generally not a withdrawal symptom of taking drugs?
a) Excessive sweating
b) Tremors and cramps
c) Insomnia
d) Hypersomnia
Answer: d
Clarification: Withdrawal symptoms are unpleasant psychological and physical symptoms that appear on the sudden stoppage of addictive drugs. For e.g., Excessive sweating, Tremors, fits, Convulsions, disturbed sleep or Insomnia.

8. Why does the dependence on drugs keep on increasing with time?
a) The tolerance level of receptors present in our body increases
b) Drugs become refreshing
c) To remain in euphoria condition
d) Dependence on food decreases
Answer: a
Clarification: With repeated use of drugs, the tolerance level of receptors present in our body increases. Consequently, the receptors only respond to higher doses of drugs or alcohol leading to greater intake and addiction.

9. Which of the following is not a common warning sign of drug and alcohol abuse among the youth?
a) Drop-in academic performance
b) Unexplained absence from school or college
c) Isolation
d) Positive attitude towards life
Answer: d
Clarification: The most common signs of drug and alcohol abuse among youth are a drop in academic performance, unexplained absence from school or college, lack of interest in personal hygiene, isolation, fatigue, depression, aggressive and rebellious behaviour, loss of interest in hobbies and deteriorating relationships with family and friends.

10. People who take drugs intravenously are less likely to acquire serious infections like AIDS and Hepatitis.
a) True
b) False
Answer: b
Clarification: People who take drugs intravenously are much more likely to acquire serious infections like AIDS and Hepatitis B. The viruses which are responsible for these diseases, are transferred from one person to another by sharing of infected needles and syringes.

11. Which of the following drugs is generally not misused by sportsperson?
a) Narcotic analgesics
b) Anabolic steroids
c) Vicks
d) Diuretics
Answer: c
Clarification: Certain sportspersons misuse drugs to enhance their performance. They misuse narcotic analgesics, anabolic steroids, diuretics and certain hormones in sports to increase muscle strength and to promote aggressiveness and as a result, increase athletic performance.

12. Which of the following is not a side effect of anabolic steroids on females?
a) Breast Enlargement
b) Masculinisation
c) Increased aggressiveness
d) Mood swings
Answer: a
Clarification: The side-effects of the use of anabolic steroids in females include masculinisation, (features like males), increased aggressiveness, mood swings, depression, abnormal menstrual cycle, excessive hair growth on the face and body, enlargement of clitoris, deepening of voice.

13. Which of the following is not a side effect of anabolic steroids on males?
a) Decreased sperm production
b) Excessive hair growth on face and body
c) Premature baldness
d) Depression
Answer: b
Clarification: The side effects of the use of anabolic steroids in males include acne, increased aggressiveness, mood swings, depression, reduction of the size of testicles, decreased sperm production, the potential for liver and kidney dysfunction, breast enlargement, premature baldness, enlargement of the prostate gland.

14. Which of the following is not associated with lowering the risk of substance abuse?
a) High levels of nurturance
b) Consistent discipline
c) Good parenting
d) Persuade the child to take more drugs
Answer: d
Clarification: Good parenting that combines with high levels of nurturance and consistent discipline, has been associated with lowered risk of substance (alcohol/drugs/tobacco) abuse. It is best to identify the situations that may push an adolescent towards the use of drugs or alcohol and to take remedial measures well in time.

15. Which of the following is not a common measure for prevention and control of alcohol and drugs abuse among adolescents?
a) Counselling
b) Education
c) Seeking help from unprofessional quacks
d) Avoiding undue peer pressure
Answer: c
Clarification: Some of the measures which are useful in prevention and control of drug and alcohol abuse among adolescents are proper education, counselling, seeking help from parents and teachers, avoiding undue peer pressure and seeking professional and medical help.

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Biology Online Test for Schools on “Plant Breeding for Developing Resistance to Insect Pests and for Improved Food Quality”.

1. Which of the following is another major cause for large scale destruction of crop plants?
a) Plant breeding
b) Mutation breeding
c) Insect and pest infestation
d) Hybridisation
Answer: c
Clarification: Another major cause for large scale destruction of crop plants and crop produce is insect and pest infestation. Breeding methods for insect pest resistance involves the same steps as those for any other agronomic trait such as yield or quality.

2. Which of the following characteristics does not provide insect pest resistance to crops?
a) Morphological
b) Botanical
c) Biochemical
d) Physiological
Answer: b
Clarification: Insect resistance in host crop plants may be due to morphological, biochemical or physiological characteristics. Hairy leaves in several plants are associated with resistance to insect pests. For example; resistance to jassids in cotton and cereal leaf beetle in wheat.

3. Which of the following is not a biochemical characteristic of insect resistance in crop plants?
a) High aspartic acid
b) Low nitrogen
c) Low sugar content
d) Solid stem
Answer: d
Clarification: The various biochemical characteristics of insect resistance in host crop plants include high aspartic acid, low nitrogen and sugar content, for example; in maize, leads to resistance to maize stem borers.

4. In cotton, solid stems lead to non-preference by the stem sawfly.
a) True
b) False
Answer: b
Clarification: In wheat, solid stems lead to non-preference by the stem sawfly. Smooth leaves and nectar-less cotton varieties do not attract bollworms. These are some of the morphological and physiological characteristics of insect-resistant plants.

5. The flat bean crop is not resistant to which of the following?
a) Jassids
b) Aphids
c) Fruit borer
d) Shoot
Answer: d
Clarification: Flat bean crops are resistant to Jassids, Aphids and Fruit borers. Sources of insect-pest resistance genes may be cultivated varieties, germplasm collections of the crop or wild relatives.

6. Pusa Gaurav is the variety of _________
a) brassica
b) flat bean
c) okra
d) cauliflower
Answer: a
Clarification: Pusa Gaurav is the variety of Brassica crop. Brassica is also known as rapeseed mustard. The varieties of Flat Bean, Okra and Cauliflower include Pusa Sem 2, Pusa Sawani and Pusa Shubhra respectively.

7. How many people in the world suffer from vitamin deficiencies?
a) 2 billion
b) 3 billion
c) 4 billion
d) 5 billion
Answer: b
Clarification: Three billion people in the world suffer from micronutrient, protein and vitamin deficiencies or hidden hunger because they cannot afford to buy enough fruits, vegetables and legumes, fish and meat.

8. Which of the following is not a result of the deficiencies of micronutrients?
a) Glowing skin
b) Risk of diseases
c) Reduced lifespan
d) Reduce mental abilities
Answer: a
Clarification: Diets lacking essential micronutrients- particularly iron, vitamin A, iodine and zinc- increase the risk for diseases, reduce lifespan and reduce mental abilities. More than 840 million people in the world do not have adequate food to meet their daily food and nutritional requirements.

9. Which of the following is the most practical mean to improve public health?
a) Mutation Breeding
b) Conventional Plant Breeding
c) Hybridisation
d) Biofortification
Answer: d
Clarification: Biofortification is breeding of crops with higher levels of vitamins and minerals, or higher protein and healthier fats. It is the most practical means to improve public health.

10. Which of the following is not an objective of breeding for improved nutritional quality?
a) Improving protein content
b) Improving Oil content
c) Increasing soil content
d) Improving vitamin content
Answer: c
Clarification: Breeding for improved nutritional quality is undertaken with the objectives of improving-
i. Protein content and quality
ii. Oil content and quality
iii. Vitamin content
iv. Micronutrient and mineral content

11. The Indian Agricultural Research Institute, Bangalore, has also released several vegetable crops rich in vitamins and minerals.
a) True
b) False
Answer: b
Clarification: The Indian Agricultural Research Institute, New Delhi, has also released several vegetable crops that are rich in vitamins and minerals. For example; vitamin A enriched carrot, spinach, pumpkin; vitamin C enriched bitter gourd, mustard, tomato; iron and calcium-enriched spinach; and protein-enriched beans-broad, lablab, French and Garden peas.

12. In which year, maize hybrids having essential amino acids were released in India?
a) 1999
b) 2000
c) 2001
d) 2002
Answer: b
Clarification: In 2000, maize hybrids that had twice the amount of the amino acids, lysine and tryptophan, compared to existing maize hybrids were developed.

13. Which of the following wheat variety was used as a donor for improving cultivated wheat?
a) Atlas 66
b) Atlanta 68
c) Atlas 77
d) Atlanta 90
Answer: a
Clarification: Wheat variety, Atlas 66, having a high protein content, has been used as a donor for improving cultivated wheat. Also, it has been possible to develop an iron-fortified rice variety containing over five times as much iron as in commonly consumed varieties.

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