Explore topic-wise InterviewSolutions in .

This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

1901.

Question : What is photorespiration? Explain it with diagrammatic representation.

Answer»

Solution :Photorespiration and its explanation:
( 1) Photorespiration : Respiration of chlorophyllous tissues in the presence of light is called photorespiration.
(2) Explanation of photorespiration :
(i) RUBISCO is an enzyme with active binding sites for both `CO_(2) and O_(2)`
(II) At high temperature, high light intensity and low `CO_(2)` concen- TRATION it oxidises a 5-carbon RUBP into a molecule of 3-carbon PGA and a molecule of 2-carbon phosphoglycolate.
(iii) PGA thus formed enters the Calvin cycle while phosphoglycolate undergoes dephosporylation to form glycolate in the chloroplast.
(iv) The glycolate then diffuses into the peroxisomes where it is oxidized to glyoxylate.
(v) The glyoxylate thus formed is finally converted into glycine, a 2-carbon amino acid.
(vi) Glycine now enters the mitochondria where two molecules of glycine combine with each other forming one molecule of serine and one molecule of `CO_(2)`

(vii) The serine is then taken to the peroxisome where it is converted into glycerate.
(viii) The glycerate then enters the chloroplast where it is phosphorylated to form PGA which enters the Calvin cycle.
(IX) Out of the total carbon LOST by oxygenation of RuBP, 75% is recovered and only 25% is lost as it is released as `CO_(2)`
Discussion
1902.

Question : What is photophosphorylation ? Describe noncyclic photophosphorylation with schematic representation. Give its significance.

Answer»

Solution :1. Photophosphorylation :The process by which energy rich ATP molecules are synthesized using solar energy is called photophosphorylation.
2. Noncyclic photophosphorylation : Noncyclic photophosphorylation is a kind of photophosphorylation which involves a continuous unidirectional flow of electrons from water to PS II, from PS II to PS I and finally to NADP. It is completed in the following steps :
(i ) Photoexcitation of photosystem I (PS I) :
(1) The photosynthetic pigments of PS I (photosystem I ) sbsorb the energy of photons which is funnelled to the reaction centre `P_(700)` (chlorophyll-a).
(2) The energy of photons are converted into the energy of electrons which are raised to high energy level (orbit ) as chlorophyll-a is excited by the absorbing light .
(3) The electrons raised to high energy level are then accepted by FRS (Ferredoxin reducing substance).
(4) The electrons from FRs are transferred to ferredoxin (Fd) as a result of which it is reduced.

(5) The electrons from reduced ferredoxin is finally taken to NADP which is reduced to NADPH.
(6) NADP retains the electrons and becomes negatively charged, while `P_(700)` owing to loss of electrons becomes positively charged i.e., ionized.
(ii) Photoexcitation of PS II and flow of electrons from PS II to PS I :
(1) The photosynthetic pigments of photosystem II absorb the energy of photons which funnelled to the reaction centre of PS II, i.e., `P_(680).`
(2) The energy of photons is converted into the energy of electrons which are raised to high energy level.
(3) The electrons that are raised to high energy level are accepted by plastoquinone (PQ) leaving the reaction centre ionized. As a result of this PQ is reduced.
(4) The electrons from PQ then pass through an electron transport chain consisting of cytochrome-`b_(6)`, cytochrome-f and phastocyanin during which they lose energy, i.e., de-energize.
(5) The de-energized electrons are transferredfrom plastocyanin to the reaction centre `P_(700)` of PS I. This shows that PS II REPLACES the lost electrons to PS I.
(6) During the transfer of electrons from cytochrome-`b_(6)` to cytochrome-f the released energy is utilized for the syntheses of ATP from ADP and iP.
(iii) Photolysis of water :
(1) `P_(680)` of pohotosystem II (PS II) behaves like a strong oxidizing agent. Therefore, it brings about the photolytic splitting of water molecule is called photolysis of water.
(2) When four electrons `(e^(-))` are removed from the reaction centre of PS II, they bring about the splitting of four water molecules into `4H^(+)` and `4OH^(-)`ions.
(3) The hydroxyl ions `(4OH^(-))` thus produced donate the electrons to the reaction centre `P_(680)` as a result of which they become 4OH radicals.
(4) The 4OH radicals then react among themselves and form two molecules of water with the release of oxygen as shown under :
`4OH to 2H_(2)O + O_(2)`
The net products of noncyclic photophosphorylation are ATP, NADPH and `O_(2)` . ATP and NADPH are utilized in the dark REACTIONS of photosynthesis while oxygen is released.
Significance of photophosphorylation :
(1) Noncyclic photosphorylaion brings about the photolysis or water and release of molecular oxygen to the atmosphere.
(2) It involves the formation of ATP and `NADPH_(2)` Which possess the assimilatory POWER. This assimilatory power is utilized in the dark reaction of photosynthesis.
(3) ATP provides energy for the synthesis of carbohydratesduring the dark reaction of photosynthesis.
(4) `NADPH_(2)` possesses reducing power which is utilized in the reduction of `CO_(2)` to carbohydratesduring the reaction of photosynthesis.
Discussion
1903.

Question : What is 'photorespiration'? Explain it with diagrammatic representation.

Answer»

SOLUTION :Photorespiration is the RESPIRATION of chlorophyllous TISSUE in the presence of LIGHT.
Discussion
1904.

Question : What is 'photophosphorylation' ? Describe non-cyclic photophosphorylation with schematic representation. Give its significance.

Answer»

Solution :Photophosphortlation : The process in which energy rich ATP molecules are synthesised USING solar energy is called PHOTOPHOSPHORYLATION.
Non-cyclic Photophosphorylation : It involves photolysis of water and a continuous unidirectional flow of electrons from water to PS-I, from PS-II to PS-I.
Non-cyclic photophosphorylation involves the following steps :
(i) Photoexcitation of PS-II : PS-II absorbs light and gets excited, which results in ionisation of CHLOROPHYLLA and a high energy electron is emitted from PS-II.
(ii) Electron acceptors : The expelled energy rich electron is first accepted by Co-Q (Co-enzyme quinone). Electron from Co-Q moves down through various electron carries and releases energy. From Co-Q, electrons are transferred to plastoquinone (PQ).
From PQ, electrons are transferred to cytochrome complex.
From cytochrome complex, the electrons are FINALLY accepted by chlorophyll of PS-I.
(iii) Synthesis of ATP : One ATP is synthesized when electron passes from cytochrome `b_(6)` to cytochrome f.
(iv) Photoexcitation of PS-I : The light energy absorbed by PS-I is transferred to reaction centre `P_(700)` and get excited. The expelledenergy rich electron is first accepted by unkonwn electron acceptor called FRS (Freedoxin Reducing Substance).
Electron from FRS moves down through various electron carries and release energy.
From FRS, electrons are transferred to ferredoxin the reduced ferredoxin transfers electrons to NADP to form NADP in the presence of enzyme Fd-NADP reductase.
(v) Photolysis of water : Splitting of water into `H^(+)` and `OH^(-)` in presence of light and chlorophyll is called photolysis of water. Manganeses, calcium and chloride ions present in PS-II and proton needs of NADP.
(vi) ATP and `"NADPH"_(2)` together called as assimilatory powers by Calvin, as it is required for assimilation of `CO_(2)`.
Significance of Non-cyclic photophosphorylation :
1. It yields ATP
2. It yields `"NADPH"_(2)`
3. It yields metabolic `"H"_(2)"O"`
Discussion
1905.

Question : Photolysis of water.

Answer»

SOLUTION :The splitting of water MOLECULE into hydrogen and OXYGEN is called PHOTOLYSIS of water.
Discussion
1906.

Question : What is photokinesis ?

Answer»

Solution :A change in the SPEED of locomotion (or FREQUENCY of turning) in a motile organism or cell which is made in response to a change in light INTENSITY is called PHOTOKINESIS. It involves undirected random MOVEMENT in response to light.
Discussion
1907.

Question : What is phenomenon for maintaining water and osmotic concentration of the blood termed as?

Answer»


ANSWER :OSMOREGULATION
Discussion
1908.

Question : What is phenotype ?

Answer»

Solution :The TERM PHENOTYPE refers to the observable CHARACTERISTIC of an ORGANISM.
Discussion
1909.

Question : What is pH of blood?

Answer»

SOLUTION :The PH of BLOOD is 7.4
Discussion
1910.

Question : What is perisperm ?

Answer»

Solution :In some plants , the NUCELLAR tissue is not utilized by the EMBRYO completely , a small portion will remain as a STORAGE tissue in the SEED, which is called as perisperm . E.g . Black Pepper.
Discussion
1911.

Question : What is Perisperm?

Answer»

SOLUTION :The residual persistant nucellus in the SEEDS of BLACK pepper and BEET.
Discussion
1912.

Question : What is periodic abstinence ?

Answer»

Solution :It 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.
Discussion
1913.

Question : What is percentage ratio of insect species from known organisms ?

Answer»

75
61
53
47

Solution :61
Discussion
1914.

Question : What is per cent rate of growth of human population in the world?

Answer»

SOLUTION :2 PER cent per ANNUM CURVE.
Discussion
1915.

Question : What is pedogenesis ?

Answer»

Solution :PEDOGENESIS is the PROCESS of FORMATION of SOIL (EMBRYONIC soil) from the rock materials by weathering
Discussion
1916.

Question : What is pedosphere ?

Answer»

SOLUTION :PEDOSPHERE: The OUTER soil zone of the EARTH. Soil profile: Soil is formed by MANY horizontal layers called soil profile
Discussion
1917.

Question :What is pedigree analysis ? Suggest how such an analysis can be useful ?

Answer»

Solution : Pedigree analysis is the study of TRANSMISSION of particular traits over the generations for finding out the POSSIBILITY of their occurrence in the FUTURE generation.
= Importance of pedigree analysis is as follows: (1) It is used to known the possibility of expressive or recessive allele, which may cause genetic disorders. (ii) It shows the origin of trait and inheritance pattern of that trait in a family. (iii) It predicts the harmful EFFECTS of marriage between close relatives. (iv) It is EXTENSIVELY used in medical research.
Discussion
1918.

Question : What is pedigree analysis? Draw schematic representation of Autosomal dominant trait (Myotonic dystrophy).

Answer»

SOLUTION :Analysis of traits in SEVERAL generations of a family is called - pedigree analysis. It is UTILIZED to TRACE the inheritance of specific trait, ABNORMALITY or disease.
Discussion
1919.

Question : What is parturition? Which hormones are involved in induction of parturition?

Answer»

SOLUTION :Delivery of child is known as PARTURITION or BIRTH PROCESS. OXYTOCIN and relaxin help in parturition.
Discussion
1920.

Question : What is parturition? Which hormones are involved in induction of parturition.

Answer»

Solution :Parturition or childbirth is the process of delivery of baby at the end of pregnancy through vigorous contractions of UTERUS.
RISE in ESTROGENS to PROGESTERONE RATIO and rising level of oxytocin induce parturition.
Discussion
1921.

Question : What is Parturition?

Answer»

SOLUTION :Parturitionis theexpulsionofyoungonefromthemother'suterusat THEENDOF GESTATION .
Discussion
1922.

Question :What is parthenogenesis? Give two examples from animals.

Answer»

Solution :Development of an egg into a COMPLETE individual without fertilization is known as PARTHENOGENESIS. It was FIRST DISCOVERED by Charles Bonnet in 1745.
E.g. Honey bees, Aphis.
Discussion
1923.

Question : What is parthenogenesis? Give two examples from animals.

Answer»

SOLUTION :Development of an egg into a complete individual without fertilization is KNOWN as parthenogenesis. It was first DISCOVERED by Charles Bonnet in 1745.
E.g. Honey bees, Aphis.
Discussion
1924.

Question : What is parthenogenesis? Give two examples.

Answer»

Solution :Female gamete developing into NEW ORGANISM WITHOUT the process of fertilization.
Eg : ROTIFERS, honeybees, some lizards and TURKEY birds.
Discussion
1925.

Question :What is parthenogenesis? Give two examples.

Answer»

Solution :Parthenogenesis is a type of reproduction in which the offspring develops from the FEMALE gamete WITHOUT UNDERGOING the PROCESS of fertilization.
Eg : ROTIFERS, Honey bees, some lizards and birds (turkey)
Discussion
1926.

Question : What is parthenogenesis?(A) Development of fruit without hormones(B) Development of fruit without fertilization(C) Development of egg without fertilisation(D) Development of embryo without fertilisation

Answer»

DEVELOPMENT of FRUIT without hormones
Development of fruit without fertilization
Development of egg without fertilisation
Development of EMBRYO without fertilisation

Answer :C
Discussion
1927.

Question : What is Parthenocarpy?(A) Development of egg without fertilization(B) Development of fruit without fertilization(C) Development of seed without fertilization(D) Development of egg with fertilization

Answer»

Development of egg WITHOUT fertilization
Development of FRUIT without fertilization
Development of SEED without fertilization
Development of egg with fertilization

Answer :B
Discussion
1928.

Question : What is parallelism?

Answer»

ADAPTIVE DIVERGENCE
Adaptive divergence of WIDELY SEPARATED species
Adaptive CONVERGENCE in widely separated species
Adaptive convergence in widely separated species

Answer :D
Discussion
1929.

Question : What is paleo climatology?

Answer»

SOLUTION :Palaeoclimatology : HELPS to reconstruct past climates of our planet and flora, fauna and ECOSYSTEM in which they lived. Example: Air bubbles trapped in ICE for TENS of thousands of years with fossilized pollen, coral, plant and animal debris.
Discussion
1930.

Question : What is ozone layer? Why it is essential?

Answer»

Solution :Ozone layer is a region of Earth.s stratosphere that ABSORBS most of the sun.s ULTRA violet radiation. The ozone layer is ALSO called as the ozone shield and it ACTS as a protective shieldcutting the ultra-violet radiation emitted by the sun.
Discussion
1931.

Question : What is ozone hole?

Answer»

Solution :Thinning ozone layer by the DEPLETION of ozone in the STRATOSPHERE is CALLED ozone hole. It is particularly marked over Antartic region.
Discussion
1932.

Question : What is ozone hole and where it is seen ?

Answer»

Solution :The ozone hole is a large area of THIN ozone layer in the stratosphere formed due to the depletion of ozone due to CFCS. Ozone hole is seen in the ANTARCTIC region.
Discussion
1933.

Question : What is oxidative decarboxylation?

Answer»

Solution :The OXIDATION reaction ACCOMPANIED by DECARBOXYLATION is CALLED oxidative decarboxylation.
Discussion
1934.

Question : What is ovulation? What happens to Graafian follicle after ovulation?

Answer»

SOLUTION :I. Ovulation: Ovulation is the process of rupture of mature Graafian follicle to release the OVUM from ovary into the ABDOMINAL cavity.
II. Graafian folicle is CONVERTED into CORPUS luteum after the ovulation.
Discussion
1935.

Question : What is outcrossing? What are its two benefits?

Answer»

Solution :Practice of mating of animals WITHIN the same breed but having no common ancestors on either SIDE of their PEDIGREE up to 4-6 generations.Overcomes inbreeding depression, best breeding method for animals that are below average in productivity in MILK production
Discussion
1936.

Question : What is other name of filaria? Give the scientific name of the causative germ of elephantiasis.

Answer»

SOLUTION :ELEPHANTIASIS, WUCHERERIA bancrofti
Discussion
1937.

Question : What is ornithine cycle? Where does it occur?

Answer»

Solution :ORNITHINE CYCLE takes place in liver where AMMONIA combines with CARBON dioxide to FORM urea.
Discussion
1938.

Question : What is optimum percentage of forest area recommended by the National Forest policy (1988) for the plains and the hills respectively? List any four problems caused due to deforestation.

Answer»

Solution :3% forest COVER for the plains and 67% for the hills
1. Deforestation increases atmospheric CARBON dioxide. 2. LOSS of biodiversity and GERMPLASM. 3. Leads to desertification. 4. Soil erosion and disturbance in water cycle.
Discussion
1939.

Question : What is organic farming ? Discuss the benefits of organic farming as a viable practise in the context of developing nations like India.

Answer»

Solution :The use of Biofertilisers in agriculture is called organic farming
Biofertilisers are organisms that ENRICH the nutrient quality of the soil.
The main sources of biofertilisers are bacteria, fungi and cyanobacteria.
The nodules on the roots of LEGUMINOUS plants formed by the SYMBIOTIC association of Rhizobium.
These bacteria fix atmospheric nitrogen into organic forms, which is used by the plant as nutrient.
Other bacteria can fix atmospheric nitrogen while free- living in the soil (examples AZOSPIRILLUM and Azotobacter), thus enriching the nitrogen content of the soil.
Currently, in our country, a number of biofertilisers are available commercially in the market and farmers use these regularly in their fields to replenish soil nutrients.
It REDUCES dependence on chemical fertilisers.
Benefits of organic farming (i) Soil fertility is maintained for a long period. (i) Quality of water is maintained. (ili) Farmer does not have to spend money on buying pesticides and insecticides so organic farming is a economic option. (iv) Through organic farming nutritious food and high quality of crops could be produced.
Discussion
1940.

Question : What is 'Oni'? Why is it considered important during cloning of a vector?

Answer»

SOLUTION :SPECIFIC SEQUENCES of DNA where replication STARTS
Helps in the replication of alien DNA when attached to Ori
Controls copy number
Discussion
1941.

Question : What is oogenesis? Give a brief account of oogenesis.

Answer»

Solution :The PROCESS of FORMATION and maturation of OVUM is CALLED OOGENESIS.
Discussion
1942.

Question : What is oligospermia?

Answer»

SOLUTION :The deficiency in sperm COUNT going below 20 million ml of seminal fluid is CALLED OLIGOSPERMIA.
Discussion
1943.

Question : What is obtained through Trichoderma Polysporum yeast?(A) Riboflavin(B) Hydroxyprogesterone(C) Streptokinase(D) Cyclosporine A

Answer»

Riboflavin
Hydroxyprojesteron
Streptokinase
CyclosporineA

SOLUTION :CyclosporineA
Discussion
1944.

Question : What is obtained from the plant Erythroxylum coca and mention its effects on human body?

Answer»

Solution :Coca alkaloids or cocaine is obtained from the coca plant a native to South America.
It is obtained from dry leaves and BRANCHES of coca plants.
It interferes with the transport of the neurotransmitter DOPAMINE.
Cocaine commonly called coke or crack is usually shorted.
It has potent stimulating action on central nervous system, producing a SENSE of euphoria and increased energy .
Excessive dosage of cocaine causes hallucinations, sleeplessness and obstructs hunger.
Atropa belladonna and Datura plants also cause hallucinations.
The abuse of cocaine leads to severe headache, SEIZURES or heart FAILURE or failure of respiratory system leading to death.
Discussion
1945.

Question : What is oestrous cycle ?

Answer»

Solution :The females of placental animals exhibit cyclic CHANGES in the activities of ovaries and accessory ducts as well as hormones during reproductive phase.
In non - PRIMATE animals this cycle is called as oestrous cycle.
E.g., cow, sheep, rat, deer, dog, TIGER, ETC.
Discussion
1946.

Question : What is nutrient cycling?

Answer»

Solution :The movement of nutrient ELEMENTS through the VARIOUS COMPONENTS of an ecosystem is CALLED nutrient CYCLING.
Discussion
1947.

Question : What is nullisomy?

Answer»

Solution :Loss of a pair of HOMOLOGOUS chromosomes or two pairs of homologous chromosomes from the diploid set are called NULLISOMY (2n-2) and double Nullisomy (2n-2-2) respectively. Selfing of MONOSOMIC plants produce nullisomics. They are USUALLY LETHAL.
Discussion
1948.

Question : What is nucleosome? How many base pairs are there in a typical nucleosome?

Answer»

Solution :The negatively charged DNA is WRAPPED around the POSITIVELY charged histone octamere to form a structure called nucleosome. A TYPICAL nucleosome CONTAINS 200 bp of DNA HELIX.
Discussion
1949.

Question : What is nuclear fall out ?How does it reach livingorganisms ?

Answer»

Solution :Nuclear fall - outrefers to settlingdown of radiocative PARTICLE from theairon the land . FROMTHE soil,theseareabsorbed by plants , whence they REACH the animalsand HUMANS VIA food chains .
Discussion
1950.

Question : What is not true for DNA replication?

Answer»

DNA CHAIN can grow in the 3'`to` 5’ direction.
DNA template is required for DNA replication.
RNA polymerase helps in copying a DNA SEQUENCE mto an RNA sequence.
DNA replication STARTS at specific sites called Ori sites.

Answer :A
Discussion