CBSE Class 12 Biology Value Based Questions All Chapters Set B

REPRODUCTION IN ORGANISMS

Question. Raju’s younger sister has seen a banana tree in backyard of a house. She could see the fruits but no seeds. She wants to know how a new plant of banana will be produced without seed. What will you explain to your sister?
Answer: In banana the vegetative propagation is occurs with the help of rhizome Values Awareness Observation

Question. Ram is a person of age 42 years old living in a village of Assam. His house is surrounded by a number of bamboo trees but he could not see any flower on them until now. What can be the explanation of his observation? How does bamboo reproduce?
Answer: Bamboo flowered once in its life time after 50-100 years. Therefore he could not see any flower on bamboo trees. Bamboo reproduce vegetatively by rhizome and sexually once in its life time. Values Observation Knowledge.

Sexual Reproduction in Flowering Plants

Question.Your younger brother becomes confused because mango fruit has only one seed, orange has many seeds while grapes have no seed at all. He wants to know how a fruit has many; one or no seed at all. What will be your explanation to your brother?
Answer: Mango has only one ovule (apocarpous ovary) while orange has many ovule (syncarpous ovary ).

Values

*Eagerness

*Scientific attitude

Question. There are two person A & B living in the ONGC colony Sivas agar ,they are neighbor and planted bottle gourd plant in their garden but the plant of person A bears fruits while plant of Mr. B has no fruit at all. Although the physical condition same for both. What will be your explanation to them?
Answer: Bottle gourd is unisexual plant and only plant with female reproductive plant can bear fruits.

Value

*Scientific observation

Human reproduction

Question. A mother gives birth to a baby. Soon after delivery, the mother-in-law insists of giving water and honey to the new born. But the father of the baby opposed this decision and took the baby to the mother of the newborn, so that the baby gets the first milk.

a) What is the milk called which comes out of the mammary gland of the mother during the initial days of lactation? What is its significance?
b) What value can you find in the father of the baby?
c) Name the hormones which influence lactation.
Answer: a) Colostrum. It contains several antibodies needed to develop resistance in the newborn.
b) The father is well informed, aware and caring.
c) Prolactin, oxytocin and progesterone.

Question. A pregnant woman gets developed some rashes on her skin. Thinking of allergy, she took some medicines without consulting any doctor.
a) Give a technical term to the agents which may cause malformation in the foetus.
b) Give suggestions, what should that pregnant woman do in such condition?
c) Which fluid in the uterus can be used to detect any abnormalities in the foetal development?
Answer: a) Teratogens 
b) The pregnant woman must consult a doctor before taking any medicine
c) Amniotic fluid.

Reproductive health

Question. A woman is tortured by in-laws as she gave birth to female child every time. They forced her to determine the sex of the foetus. (a) What do they do? (b) Who is responsible for the sex of the child – mother/ father? (c)Is the behavior of in-laws towards her right or wrong? Give your opinion.
Answer: (a) Amniocentesis (b) Father (c ) Wrong

Question. Generally it has been seen that male refuses for vasectomy .As they think that it will affect their health and strength. What will you do in that condition? 
Answer: Try to create awareness among them regarding vasectomy.

PRINCIPLES OF INHERITANCE AND VARIATION

Molecular basis of inheritance.

Question. A child born to a couple was claimed by another man in the hospital. What is the methodology used to solve the paternity dispute? 
Answer: DNA fingerprinting, Value:- problem solving, critical thinking, decision making.

Question. Two claimant fathers filed a case against a lady claiming to be the father of her only daughter. How could this case be settled identifying the real biological father?
Answer: Yes, this case can be settled identifying the real biological father by DNA fingerprinting. Value:--problem solving, critical thinking, decision making.

Question. The police department could obtain a bunch of hair from the gripped hand of a murdered man. There were two persons arrested in this criminal case. How will the forensic department, give a clue to the criminals?
Answer: The forensic department is claimed out the investigation by DNA fingerprinting for identifying the real murderer.
Value:-- Problem solving, decision making ,critical thinking.

Question. A man with blood group A and his wife blood group B have a son with blood group O, father claim that was not his son. How can the problem be solved? 
Answer: Real father can be identified by blood group analysis and with DNA fingerprinting. Value:---critical thinking ,trust making.

Evolution

Question. Sometimes Gene flow or Gene migration is harmful for a population why?
Answer: Gene flow or gene migration of good genes from a population is harmful for the original population.

Question. Penicillin was once called wonder drug as it could heal most of the bacterial infections. It is no longer used now. Suggest the possible reasons for this.
Answer: Mutations occur in nature. It also occurs in pathogens. Some of these mutations caused adaptations to resist the attack of antibiotics. Chapter No.8 Chapter: Prepared by: Ranchi Region Human health & diseases.

Human health & diseases

Question. Some international sports persons failed in dope tests& not allowed to participate in Olympics as they were drug abusers
i) Name the drugs that would have been taken by them.
ii) Why did they use such drugs?
Answer: i) Anabolic steroids, certain hormones, diuretics & narcotic analgesics. 
ii) To increase muscle strength& to increase athletic performance

Question. Some human diseases are transmitted only when the blood of a patient comes in contact with the blood of a healthy person. In one of such disease, there is a progressive decrease in the number of lymphocytes of the patient.
i) Name the disease & its causative agent
ii) Name the type of lymphocytes affected due to this infection.
Answer: i) AIDS caused by HIV
ii) T-lymphocytes

Question. Health is the basic to life, and is essential for the good results in any sphere of life. A factory owner cannot expect the optimum output, if he does not employ healthy workers. A farmer cannot get optimum yield in his fields, if he is not healthy. What does health actually mean? How is it related to our personal life & professional efficiency?
Answer: A state of complete physical, mental & social well- being. A healthy person is more efficient at work. Increases productivity & brings economic prosperity.

Strategies for enhancement in food production

Question. Differentiate between inbreeding and out-breeding?
Answer: Inbreeding is between animals of same breed. Outbreeding is the crossing between different breeds.

Question. What role is played by heterozygosity in the improvement of breeds?
Answer: Reduces inbreeding depression.

Question. What is interspecific hybridization?
Answer: Male and female of two different related species are mated. Ex-Mule

Question. Expand MOET.
Answer: Multiple ovulation embryo transfer technology.

Question. Write the economic importance of honey bee.
Answer: Food of high nutritive value, indigenous of medicine, produces bee-wax, preparation of cosmetics and polishes, etc. 

Question. How would an aquaculture and pisciculture be helpful in our life?
Answer: Lead to the development, flourishing and fishery industry, which brought lot of income to the farmers.

Question. What do you mean by Single Cell Protein?
Answer: It is alternate sources of proteins for animal and human nutrition.

Question. How micro-propagation is helpful in producing thousands of plant?
Answer: By application of these methods it is possible to achieve propagation of large number of plants in very short time.

MICROBES IN HUMAN WELFARE

Question. Municipal Corporation has deputed personnel to check for mosquito breeding in your school.
a) Which are the places they should check for mosquitoes and there larvae?
b) Name to diseases which are spread by mosquitoes.
c) Name any two biological agents which can be used to control mosquitoes
Answer: 1. A. Toilet, Corners of the Vidyalaya, Unused pots and puddles. B. Gambusia fish in pond, Dragon flies, Ladybird.

Question. Prabha has seen huge garbage dumps outside your school which are not being regularly disposed of by MCD / Nagar Parishad. Prabha discusses the problems with school mates and decide to organize rally to spread awareness among local people about public hygiene.
A. Prepare two slogans for rally
B. Name any two infectious diseases which may spread due to such unhygienic conditionsat public place.
Answer: A. Cause the garbage removal, and help in proper disposal.; kachra hataao, bimari bhagaao; ghar bahar rahe savacch hamara, rog mukt rahe jeevan hamara.
B. Malaria, Typhoid, Dengue Chapter No.11 Chapter: BHUBANESWAR Region Biotechnology: Principles & Processes

Question. Pushpender is a scientist working on GMOs to produce Transgenic Buffaloes which can produce milk of medicinal properties. But he also found adverse effects on which they reduce their life span. Based on this, Answer the following.
a) What values are being neglected by him?
b) Should he continue with transgenic production of Buffaloes? 
c) What Reactions and Reflections would he face from various organizations?
Answer: a) Empathy and Respect towards animals.
b) Such practices may kill innocent animals as the life span of buffaloes becomes less.
c) Organizations like GEAC may object on violating animal atrocity rules.

Question. Sandeep is a Biology Student of class xii. He learnt from his teacher that lack of insulin hormone in our body can be injected through syringes. One day his father shows symptoms of Diabetics and he suggested him to meat doctor for Diagnosing Insulin product. On the basis, Answer the following questions.
a) What did Sandeep understands about insulin?
b) On what basis did Sandeep advice his father?
c) Which American based company produced insulin at first and in which year?
Answer: a) Insulin is a Hormone; it regulates blood sugar level in the body. Less secretion can be Injected extracellular.    
b) In support and affection when he saw his father suffers.
c) An American Based company called Eli Lilly in 1983.

Question. Gel Electrophoresis a Technique used to separate DNA fragments after the function of Endonuclease. Sushi couldn’t understand the actual function of Restriction Endonuclease. He takes the help of his friend sham by asking the questions. On the basis answer the following.
a) What is the difference between Exonuclease and Endonuclease?
b) Why sham did help his friend Sushi?
c) How can we see DNA fragments after the separation?
Answer: a) Exonuclease cut DNA at ends externally
Endonuclease cut DNA at specific base sequence within the DNA.
b) Out of support and improvement of his Friend to generate knowledge.
c) The separated DNA fragments are visualized after staining the DNA with Ethidium bromide followed by exposure to UV radiation.

Question. In a village Two friend farmers Ramnath and Kishan are cultivating normal cotton saplings. Every year they suffer and get fewer yields and lose money. One day Kishan watches add in television on Bt Cotton and encourages his fellow farmer, they were surprised by seeing high yield. Based on this, answer the following.
a) What is Bt cotton?
b) What way Bt kills lepidopteron, coleopterans and dipterans in the soil? 
c) How could the information passed on to the farmers? What is the value that a fellow farmers can learn from this?
Answer: a) Bacillus thuringiensis a soil bacterium.
b) Soil bacterium produces specific cry proteins which kill insects.
c) The information is advertised in television so as to bring awareness among people. All the farmers should be alert to learn changes occurring in the field of agriculture, show sympathy on farmers in their loss.

Question. Genes encoding resistance to antibiotics like Ampicillin, chloramphenicol, tetracycline are useful selectable markers for E.coli. The normal E.coli cells do not carry resistance against any of these antibiotics. Ankita wants to know more clarity on these scriptures. She asks doubts to her teacher. Based on this please answer the following.
a) Name the best known plasmid vector?
b) What are selectable markers?
c) On what basis Biology teacher advices Ankita.
Answer: a) p BRr322 ( Plasmodium Bolivar Rodriguez 322)
b) Selectable markers help the host cells to select useful transformants. Antibiotic are genes encoding selectable markers.
c) Out of teacher student relationship and to equip the knowledge.

Question. Jevan’s friend’s uncle suffers from reduced body weight loss. He suspects HIV. He wants to diagnose immediately. But due to shy he delays to meet doctor. One day Jevan came to know and advices him to go for ELISA or PCR Test. Based on these answer the following questions?
a) What are ELISA and PCR?
b) What makes Jevons uncle feel shy to meet doctor?
c) What are the steps involved in PCR?
Answer:  a) Enzyme Linked Immunosorbent Essay and Polymerase Chain Reaction
b) Immediate loss of body weight may suspects to HIV. Therefore with an Empathy Jevon suggested for ELISA and PCR. 

               i) Denaturation        ii) Annealing       iii) Extension       iv) Amplification

Organisms and Population

Question. Now a day’s animals are coming out of the forest and create problems in the nearby areas. Give the possible reasons.
Answer: Causes of Habitat destruction with explanations

Question. Increasing population in India is the cause of failure behind many planning of Govt. Study of the population attributes helps the country in this situation. Give your Opinion. 
Answer: Different characters of population, methods to control birth.

Ecosystem

Question. A large area of farmland in our country is facing the problem of less soil fertility. According to you which aspect of ecosystem helps us and how?
Answer: Humification and Mineralization

Question. Recently it was revealed that poaching of animals in their areas. How does it affect the ecosystem? 
Answer: Disturb the ecosystem

BIODIVERSITY & CONSERVATION

Question. You find that a lake in your neighboring area has been covered by Water hyacinth. You have contacted your friends to remove this weed. Nobody agrees to support you. How will you explain the necessity of this?
Answer: Water hyacinth grows rapidly; absorb dissolve oxygen and nutrients from aquatic bodies.

Question. A well- known personality killed a black buck during hunting in sacred groves of Aravali Hills in Rajasthan. Local people caught him and lodged a case in court against him. He argued that court that killing a human being is a crime but killing an animal is not crime. What is your opinion?
Answer: Back buck being endangered animal is prohibited from hunting; as such it is also an equal crime to that of killing a human being.

Question. Students were taken for excursion to Arabari Joint forestry Project in Midnapore district, West Bengal .The various observations done by the students were as follows— (i)Village people using forest products without causing harm to forest.
(ii) Village people helping in plantation in deforestation areas.
(iii) A core area under the forest is not disturbed by anybody.
State the various inference which the students draw from the observations
Answer: (i) Conservation and utilization of forest products substantially

        (ii) Protection of forest

        (iii) In-situ Conservation

Question. A sudden decline in fruits and seeds were seen in an area where regular heavy use of insecticides was done for the past few years. Give reasons for such an outcome.
Answer: Pollination is possible with the help of insects. Decline in insect population- --bees, bumble bees, birds and bats are very important pollinating agents.

Question. A debate was conducted on school on the need to conserve biodiversity. One student felt that there are so many species on the earth, why will it matter if we lose a few. Do you feel the same .Justify your answer.
Answer: We are losing species more quickly than the evolutionary process can replace. Once a species become its role in the ecosystem is eliminated, leaving a void and weakening ecosystem function and services.

Question. Study-1.A forest that is rich in biodiversity seems to decline in animal population. The government declared it as a biodiversity hotspot and the forest regained its species richness in few years.

Study-2.A lake that is rich in marine fishes seems to decline in its species population due to overexploitation. A wise man in the area decided to worship the lake. The species population f the lake again became normal.
(a) Which values are been promoted in the above studies.
(b) Suggest some ways by which you can contribute to this concern.
(c) What would be the effect if the forest was not declared hotspot?
Answer: (i) Biodiversity conservation, Ecosystem protection.
(ii) Educate people not to harm biodiversity. 
(ii) Forest would be destroyed, many species of plants and animals lost.

Please refer to the link below for CBSE Class 12 Biology Value Based Questions All Chapters Set A