24277 + Interview Questions in Biology in Class 12 Page 459 InterviewSolution

22901.	Question : What is Population density? Write the factors that influence population density.
Answer» SOLUTION :a) 1) NATALITY 2) Mortality 3) Immigration Emigration

Discussion

22902.	Question : A tall pea plant bearing violet flowers is given with its unknown genotyoes. Explain by working out the crosses how would you find the correct genotypes with respect to the two traits mentioned only by "selfing" the given plants.
Answer» Solution :Tall pea Plants with VIOLET FLOWERS, POSSIBLE GENOTYPES.

Discussion

22903.	Question : (a) Write about the various structures of female’s external genitalia. (b) Explain any two methods of natural contraception.
Answer» Solution :(a) Mons pubis is a cushion of fatty tissue covered by skin and pubic hair. The labia majora are FLESHY folds of tissue, which extend down from the mons pubis and surround the vaginal opening. The labia minora are paired folds of tissue under the labia majora. The opening of the vagina is often covered partially by a membrane called hymen. The clitoris is a tiny finger-like structure which lies at the upper junction of the two labia minora above the urethral opening. (b) (i) Periodic abstinence is a method in which the COUPLES avoid or abstain from coitus from day 10 to 17 of the menstrual cycle when ovulation could be expected. As chances of fertilisation are very high during this period, it is called the fertile period. Therefore, by abstaining from coitus during this period, conception could be prevented. (ii) Withdrawal or coitus interruptus is a method in which the MALE partner withdraws his PENIS from the vagina just before ejaculation so as to avoid insemination. (iii) Lactational amenorrhea (absence of menstruation) method is based on the fact that ovulation and therefore the cycle do not occur during the period of intense lactation following parturition. Therefore, as long as the mother breast-feeds the child fully, chances of conception are ALMOST nil. However, this method has been reported to be effective only upto a maximum period of six months following parturition.

Discussion

22904.	Question : (a) Taking one example each of habitat loss and fragmentation, explain how are the two responsible for biodiversity loss. (b) Explain two different ways of biodiversity conservation.
Answer» Solution :(a) (i) When large-sized HABITATS are broken or fragmented due to human settlements, building of mads, digging of canals, etc. animals requiring large territories and some animals with MIGRATORY habitats are badly affected. (ii) The Amazon rain forest (called the “lungs of the planet”) is being cut and cleared for cultivation of soya beans or for conversion intq grasslands for raising beef cattle. (b) There are two basic approaches for conservation of biodiversity. (i) ‘In-situ’ Conservation (on SITE conservation) (ii) ‘Ex-situ’ conservation (off site conservation) In-Situ Conservation : It is conservation and protection of biodiversity in its natural habitat. (ii) It helps in recovering population in the surroundings where' they have developed their distinctive features. Example : national parks, biosphere reserves, WILDLIFE sanctuaries. Ex-Situ Conservation : It is conservation of selected rare plants and animals in places outside their natural habitat. (ii) It helps in recovering population or preventing their extinction under conditions that closely resemble their natural habitats. Examples :botanical gardens, ZOOLOGICAL parks, Wildlife safari, gene banks, etc.

Discussion

22905.	Question : a)Write a note on homologous organs. b)Write the scientific name of man like primate who lived in East African grasslands about 3 - 4 million years ago.
Answer» SOLUTION :(B) Australiopithecines.

Discussion

22906.	Question : A : Taj Mahal is being destroyed by SO_(2) coming from Mathura refinary. R : This converts CaCO_(3) into unstable calcium sulphate.
Answer» If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then MARK (1). If both Assertion & Reason are TURE but the reason is not the correct explanation of the assertion, then mark (2). If Assertion is true STATEMENT but Reason is false, then mark (3). If both Assertion and Reason are false statements, then mark (4). Answer :A

Discussion

22907.	Question : A T_(4)bacteriophage has an icosahdral head with
Answer» 2500 capsomeres with a 63 `MUM` long double-stranded DNA in it 2000 capsomeres with a 53 `mum` long double-stranded DNA in it 1500 capsomeres with a 40 `mum` long double-stranded DNA in it 1000 capsomereswith a 53 `mum` long double-stranded DNA in it Answer :B

Discussion

22908.	Question : A woody plant after the fall of all leaves exhibit
Answer» Stomatal transpiration Cuticular transpiration Lenticular transpiraiton 1 and 3 Answer :C

Discussion

22909.	Question : A women fails to conceive due to high acidity in the vaginal tract. Suggest any two assisted reproductive technologies for her.
Answer» Solution :IVF- In VITRO Fertilisation GIFT - GAMETE INTRA Fallopian TRANSFER

Discussion

22910.	Question : A system of rotating crops with legume or grass pasture to improve soil structure and fertility is called
Answer» CONTOUR FARMING strip farming SHIFTING agriculture LEY farming SOLUTION :ley farming

Discussion

22911.	Question : A woman with O blood group marries a man with AB blood group (i) Work out all the possible phenotypes and genotypes of the progeny.(ii) Eiscuss the kind of dominace in the parents and the progeny in this case.
Answer» Solution :(i) Blood GROUP AB has alleles as `1^A,1^B` and O group has II which on cross gives the both blood GROUPS A and B while the genotype of PROGENY will be `I^Ai and I^B i`. (ii) `I^A and I^B` are equally dominant (co-dominant). In multiple allelism, the GENE I exists in 3 allelic forms, `I^A,I^B` and i.

Discussion

22912.	Question : A swimmerbreathing through a pipe has a respiration rate of 10/min, a tidal volume of 550 ml and an effective anatomic dead space of250 ml. Whatis his alveolar ventilation?
Answer» 2500 ml/min 3000 ml/min 3500 ml/min 4000 ml/min Answer :B

Discussion

22913.	Question : A syndrome which occures due to illegitimate crossing over is
Answer» KLINEFELTER's syndrome Familial Down's syndrome Turner's syndrome Patau syndrome Answer :B

Discussion

22914.	Question : A woman with cystic fibrosis ,an autosomal recessive condition marries her first cosin.What is the risk that their first childwill have cystic fibrosis ?
Answer» `1//4` `1//2` `3//4` `1//8` Solution :The gentoype of affected woman is cc. Her parents are obligate carries (Cc) and ONE of her grand parents must also be a carrier. Her FIRST cousin then has a 1/4 CHANCE being a carrier.He has 1/2 chance of transnmitting his c allete if it is present.So the chance of CHILD being a PATIENT of cystic fibrosis is `1//4xx1//2=1//8`

Discussion

22915.	Question : A survey was carried out to investigate the relationship between the human population density and elephant population density in Zimbabwe. Twenty five sites were sampled, all within a 15000"km"^(2) area in the North of the country.
Answer» ANSWER :d

Discussion

22916.	Question : A woman with cstic fibrosis, anautosomal recondition, marries her first cousin. What is the risk that their first child will have cystic fibrosis?
Answer» 0.25 0.5 0.75 0.125 Answer :D

Discussion

22917.	Question : A survey conducted by Nature club in your school in the nearby forest found that some species of animals are endangered. Can you suggest two methods to protect them.
Answer» SOLUTION :(I)They can be CONSERVED in Zoo.(ii)PROTECT them in wildlife SANCTUARIES

Discussion

22918.	Question : A supermale XYY is characterised by
Answer» under PRODUCTION of SEX hormones Overproduction of sex hormones Reduced intellingece but AGGRESSIVE nature Both 2 and 3 Answer :D

Discussion

22919.	Question : A sugarcane has been affected by virus. How can a virus free cane be developed from it ? Explain the procedure.
Answer» Solution :The virus free sugarcane can be developed by the PROCESS of tissue culture where in the whole plant is REGENERATED from explants. i.e., any part of a plant grown in a test tube under sterile conditions in special nutrient media. The technique makes USE of the property of TOTIPOTENCY and the fact that the MERISTEM (apical and axillary) of the sugarcane plant is free of virus. Hence, the meristem can be removed and grown In-Vitro to get disease free plant.

Discussion

22920.	Question : A suffling of alliles like a deck of cards leads to different 'hands', known as
Answer» genotypes genes flushes fossils Answer :A

Discussion

22921.	Question : A successful parasite is the one which:
Answer» GROWS rapidly Reproduces fast Sticks to HOST for long Makes MINIMUM DEMANDS from its host Answer :D

Discussion

22922.	Question : A sudden, random, discontinuous and heritable change is
Answer» GENETIC DRIFT Mutation Genetic LOAD Bottle NECK Answer :B

Discussion

22923.	Question : A substance unrelated to substrate but capable of reversibly changing activity of enzyme by binding to a site other than activesite is called
Answer» COMPETITIVE inhibitor Non-competitive inhibitor Catalytic inhibitor Allosteric modulator/inhibitor Solution :N//A

Discussion

22924.	Question : A subspecies of plains zebra that lived in South Africa has recently become extinct is
Answer» THYLACINE dodo quagga stellar SEA cow Answer :C

Discussion

22925.	Question : A substaintialfall in CO_2and SO_2 level hasbeenfoundin Delhibetween1997and 2005due to
Answer» use of purifiedunleaded petrol Use of purifiedunleaded diesel use of compressedNatural GAS (CNG ) inpublictransports use of Liquifiedpetroleam Gas (LPG ) in publictransports ANSWER :C

Discussion

22926.	Question : A student sets up an experiment on photosynthesis and it is as follows he takes soda water in a glass tumbler and adds chlorophyll extract in to the contents and keeps the tumbler exposed to sulight hoping thathehas provided the necessary ingredients what wil happen after say a few hours of exposoure to light choose the correct answer
Answer» photosynthesisi tkake PLACE and glucose would be produced TURNING the mixture sweet PHOTOSYNTHESIS will take place and starch wouldbe produced which will turn the mixture TURBID photosynthesis doesnot occur and `CO_(2)`dissolved in soda water ESCAPE in to theatmosphere photosynthesis will nottake place because intactchloroplasts are needs for the process Answer :B

Discussion

22927.	Question : Astudent observed four plants (a,b,c,d,). The number of stamens in a equal to those ofb. Flower c has ten stamens in but its bundle possesses three times the stamens of inner whorl ofa. In d the number of stamens is equal to those present in inner whorl ofb. Identify the flower .
Answer» BRASSICA,TEPHROSIA, ALLIUM, OCIMUM Tephrosia, Ocimum,Brassica, Allium Taphrosia, Allium, Ocimum, Brassica Allium, Brassica, Tephrosia, Ocimum. Answer :D

Discussion

22928.	Question : A structure which prevents food from entering the trachea in rabbits.
Answer» SOLUTION :EPIGLOTTIS.

Discussion

22929.	Question : A structure not present in Hydra occur in maximum number over
Answer» NEVER cells Epitheliomuscular cells Choanocytes/Glial cells Cnidocytes. Answer :C

Discussion

22930.	Question : A striped but-involuntary muscle is:
Answer» Cardiac Abdominal Biceps None of the above Answer :A

Discussion

22931.	Question : (a) Stream lined body (b) Four pair of gills (c) Air bladder is present (d) In males pelvic fins bear claspers (e) Two chambered heart (f) Fertilization is usually external How many statements are correct for the members of class osteichthyes?
Answer» one two five six Answer :C

Discussion

22932.	Question : [A] : Steroid hormones are similar to choles- terol in structure. [R]: Steroids contain phenanthrene ring struture.
Answer» If both A and R are TRUE and R is the CORRECT explanation of A If both A and R are true but R is not the correct explanation of A If A is true and R is false If both A and R are false Answer :B

Discussion

22933.	Question : A stirred-tank reactor is usally cylindrical or with a curved base to
Answer» give a large surface area facilitate the mixing of the reactor content AVOID the mixing of the reactor contents increase the oxygen TRANSFER area ANSWER :B

Discussion

22934.	Question : A steroid hormone which regulates glucose metabolism is:
Answer» Cortisone Cortisol Corticosterone 1,1-deoxycorticosterone Answer :B

Discussion

22935.	Question : A sterile female having reduced mental ability is said to be suffering from
Answer» TURNER SYNDROME Klinefelter.s syndrome down.s syndrome edward syndrome Solution :turner syndrome

Discussion

22936.	Question :A stele consisting of numerous closed vascular bundles is called as -
Answer» EUSTELE Dictyostele Atactostele Solenostele Answer :C

Discussion

22937.	Question : (a) State the objective of animals breeding. (b) List the impotance and limitations of inbreeding. How can the limitation be overcome ? (c ) Give example of a new breed each of cattle and poultry .
Answer» Solution :(a) Animals breeding-objectives : 1. Improve growth rate. 2. Increased production. 3. Improve Desirable Qualities. 4. Improved resistance to DISEASES. 5. Improved resistance to adverse environment conditions (b) Importance : 1. Increase homozygosity 2. To EVOLVE pureline 3. EXPOSE harmful recessive SUPERIOR genes. 5. Elimiation of less disrable genes. Limitation : 1. Reduce fertillity and productivity 2. Imbreeding DEPRESSION (c) Jersey/(Cattle)-and Leghorn (Poultry).

Discussion

22938.	Question : (a) State the central dogma in molecular biology. Who proposed it? Is it universally applicable? Explain. (b) List any four properties of a molecule to be able to act as a genetic material
Answer» Solution :(a) Francis Crick proposed the 'central DOGMA' in molecular biology which states that the genetic information FLOWS from In some viruses, the flow of information is in reverse direction, that is from RNA to DNA (b) PROPERTIES in a molecule to act as a genetic material: It should be able to generate its replica. It should chemically and structurally be stable It should provide scope for slow changes (mutation) that are required for evolution It should be able to express itself in the FORM of Mendelian characters.

Discussion

22939.	Question : (a) state the central dogma as proposed by francis crick are thereany exceptions to it ? Suppport your answer with a reason and an example (b) Explain how the biochemical chraterisation (nature) of Transforming pronciple was determined which was not defined from Griffith 's experiments
Answer» Solution :(a) Francis crick proposed the central dogma in molecular biology , which states that the genetic information flows from DNA`rarr`RNBA`rarr`Protein `DNAoverset(transcription)rarrmRNA(overset(translation)rarrProtein` In some viruses central dogma is seen in reverse direction that is from RNA to DNA as RNA is the main genetic material for example : Retro virus (HIV) and the process is reverse tarnscription (b) Tansforming principle : in 1928 fredericlk GRIFFITH INA series of experiments with straptococcus penumonie (bacteriumerepsonsiable for pneumoia) withessed a miraculous transformation in the bacteria during the course of his experiment a living organism (bacteria ) had changed in phyical form He concluded that the R strain bacteria had some how been transformed by the heat killed s strain bacteria some tramforming principle transferredfrom the heat killed s strain had enabled the r strain to sysnthises a smooth polysaccharider coat and become virulent .This must be DUE to the transfer of the genetic material .However the biochemical nature of genetic material was not defined form his experiments They also discovbeed that proteindigensting ENZYMES (proteses) and RNA disgeting enzymes (RNases) did not AFFECT transformation so the transforming substancewas not a protein or RNAdisgestion with inhibit transformation suggestion that the DNA caused the transformation They concluded that DNA is the hereditary material but not all biologist were convinced .

Discussion

22940.	Question : A state of healthy reproductive organs with normal function is _____.
Answer» ANSWER :REPRODUCTIVE HEALTH

Discussion

22941.	Question : A staminode does not contain
Answer» ANTHER Fillament Male gametes Pollen grains Answer :D

Discussion

22942.	Question : A spermatogonial cell has 30 chromosomes. How many chromosomes will be found in (i) the primary spermatocyte, (ii) a spermatid derived from this cell?
Answer» SOLUTION :(i) 30,(II) 15

Discussion

22943.	Question : A specila type of pseudocarpic berry having papery endocarp is called as
Answer» amphisarca pome balusta ACHENE ANSWER :C

Discussion

22944.	Question : A specific sequence which begins the replication of DNA is called ……............
Answer» SEQUENCE of REPLICATION Point of replication ORIGIN of replication NONE of the above SOLUTION :Origin of replication

Discussion

22945.	Question : A specific place in an ecosystem, where an organism lives and performs its functions is .......................
Answer» habitat NICHE landscape biome Solution :niche

Discussion

22946.	Question : A species or type of a plant derived from doubling the chromosome of F1 hybrid of two similar species is known as
Answer» AUTOPOLYPLOID Amphidiploid autodiploid Hexaploid Answer :A

Discussion

22947.	Question :A species is considered as extinct.
Answer» When its member is confined to a PARTICULAR AREA When its member is maintained in non-native area When none of its MEMBERS is alive in native area When none of its members alive ANYWHERE in the world Answer :D

Discussion

22948.	Question : A species facing extremely high risk of extinction in the immediate future is called :
Answer» Vulnerable Endemic CRITICALLY ENDANGERED Extinct Solution :Critically Endangered

Discussion

22949.	Question : A specialised cellular thickenings at the micropylar tip of synergids.Egg apparatusFiliform apparatusAntipodalsTapetum
Answer» EGG apparatus Filiform apparatus Antipodals Tapetum Answer :B

Discussion

22950.	Question : A species facing extremely high risk of extinction in immediate future is called :
Answer» VULNERABLE Endemic Critically ENDANGERED Extinct SOLUTION :Critically endangered

Discussion

Explore topic-wise InterviewSolutions in .

Question : What is Population density? Write the factors that influence population density.

Question : A tall pea plant bearing violet flowers is given with its unknown genotyoes. Explain by working out the crosses how would you find the correct genotypes with respect to the two traits mentioned only by "selfing" the given plants.

Question : (a) Write about the various structures of female’s external genitalia. (b) Explain any two methods of natural contraception.

Question : (a) Taking one example each of habitat loss and fragmentation, explain how are the two responsible for biodiversity loss. (b) Explain two different ways of biodiversity conservation.

Question : a)Write a note on homologous organs. b)Write the scientific name of man like primate who lived in East African grasslands about 3 - 4 million years ago.

Question : A : Taj Mahal is being destroyed by SO_(2) coming from Mathura refinary. R : This converts CaCO_(3) into unstable calcium sulphate.

Question : A T_(4)bacteriophage has an icosahdral head with

Question : A woody plant after the fall of all leaves exhibit

Question : A women fails to conceive due to high acidity in the vaginal tract. Suggest any two assisted reproductive technologies for her.

Question : A system of rotating crops with legume or grass pasture to improve soil structure and fertility is called

Question : A woman with O blood group marries a man with AB blood group (i) Work out all the possible phenotypes and genotypes of the progeny.(ii) Eiscuss the kind of dominace in the parents and the progeny in this case.

Question : A swimmerbreathing through a pipe has a respiration rate of 10/min, a tidal volume of 550 ml and an effective anatomic dead space of250 ml. Whatis his alveolar ventilation?

Question : A syndrome which occures due to illegitimate crossing over is

Question : A woman with cystic fibrosis ,an autosomal recessive condition marries her first cosin.What is the risk that their first childwill have cystic fibrosis ?

Question : A survey was carried out to investigate the relationship between the human population density and elephant population density in Zimbabwe. Twenty five sites were sampled, all within a 15000"km"^(2) area in the North of the country.

Question : A woman with cstic fibrosis, anautosomal recondition, marries her first cousin. What is the risk that their first child will have cystic fibrosis?

Question : A survey conducted by Nature club in your school in the nearby forest found that some species of animals are endangered. Can you suggest two methods to protect them.

Question : A supermale XYY is characterised by

Question : A sugarcane has been affected by virus. How can a virus free cane be developed from it ? Explain the procedure.

Question : A suffling of alliles like a deck of cards leads to different 'hands', known as

Question : A successful parasite is the one which:

Question : A sudden, random, discontinuous and heritable change is

Question : A substance unrelated to substrate but capable of reversibly changing activity of enzyme by binding to a site other than activesite is called

Question : A subspecies of plains zebra that lived in South Africa has recently become extinct is

Question : A substaintialfall in CO_2and SO_2 level hasbeenfoundin Delhibetween1997and 2005due to

Question : Astudent observed four plants (a,b,c,d,). The number of stamens in a equal to those ofb. Flower c has ten stamens in but its bundle possesses three times the stamens of inner whorl ofa. In d the number of stamens is equal to those present in inner whorl ofb. Identify the flower .

Question : A structure which prevents food from entering the trachea in rabbits.

Question : A structure not present in Hydra occur in maximum number over

Question : A striped but-involuntary muscle is:

Question : (a) Stream lined body (b) Four pair of gills (c) Air bladder is present (d) In males pelvic fins bear claspers (e) Two chambered heart (f) Fertilization is usually external How many statements are correct for the members of class osteichthyes?

Question : [A] : Steroid hormones are similar to choles- terol in structure. [R]: Steroids contain phenanthrene ring struture.

Question : A stirred-tank reactor is usally cylindrical or with a curved base to

Question : A steroid hormone which regulates glucose metabolism is:

Question : A sterile female having reduced mental ability is said to be suffering from

Question :A stele consisting of numerous closed vascular bundles is called as -

Question : (a) State the objective of animals breeding. (b) List the impotance and limitations of inbreeding. How can the limitation be overcome ? (c ) Give example of a new breed each of cattle and poultry .

Question : (a) State the central dogma in molecular biology. Who proposed it? Is it universally applicable? Explain. (b) List any four properties of a molecule to be able to act as a genetic material

Question : (a) state the central dogma as proposed by francis crick are thereany exceptions to it ? Suppport your answer with a reason and an example (b) Explain how the biochemical chraterisation (nature) of Transforming pronciple was determined which was not defined from Griffith 's experiments

Question : A state of healthy reproductive organs with normal function is _____.

Question : A staminode does not contain

Question : A spermatogonial cell has 30 chromosomes. How many chromosomes will be found in (i) the primary spermatocyte, (ii) a spermatid derived from this cell?

Question : A specila type of pseudocarpic berry having papery endocarp is called as

Question : A specific sequence which begins the replication of DNA is called ……............

Question : A specific place in an ecosystem, where an organism lives and performs its functions is .......................

Question : A species or type of a plant derived from doubling the chromosome of F1 hybrid of two similar species is known as

Question :A species is considered as extinct.

Question : A species facing extremely high risk of extinction in the immediate future is called :

Question : A specialised cellular thickenings at the micropylar tip of synergids.Egg apparatusFiliform apparatusAntipodalsTapetum

Question : A species facing extremely high risk of extinction in immediate future is called :