Answer: (4) Huxley
Sir Julian Huxley introduced the term 'New Systematics'. New Systematics aims at taking into consideration, all characteristics of organisms gathered from the study of ecology, genetics, cytology, physiology, biochemistry, behaviour, etc., for systematics.
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Vitamin D is synthesized in the skin by the action of sunlight on
(1) Cholesterol
(2) 7-hydroxy cholesterol
(3) Cephalin cholesterol
(4) All of the above
Answer: vitamin D is a steroid, which is synthesized from cholesterol. Vitamin-D2 is formed from plant sterol, ergo sterol, which occurs in yeast and other fungi in the presence of ultraviolet light. Vitamin-D3 formed from animal sterol, 7-dehydroxy cholesterol, which occurs in animal skin. Its synthesis also needs ultraviolet light
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Plant Kingdom
Which one of the following statements concerning the algae is wrong?
(1) Algae can be classified according to their pigments
(2) All algae are filamentous
(3) Spirogyra does not produce zoospores
(4) Most algae are photosynthetic
Answer: (2) All algae are filamentous
Algae include organisms that are unicellular, colonial, filamentous, or large and multicellular.
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Animal Kingdom
In which group the locomotory organelles are absent ?
(1) Flagellata
(2) Sporozoa
(3) Rhizopoda
(4) Ciliata
Answer: (2) Sporozoa Members of class Sporozoa have no specialised locomotory organelles and contractile vacuoles.
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Morphology of Flowering Plants
Annuals and biennials are typically
(1) Monocarpic
(2) Bicarpic
(3) Polycarpic
(4) Apocarpic
Answer: (1) Monocarpic
Monocarpic refers to a plant that flowers only once during its life, after fruiting, the leaves senescence and the plant dies completely.
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Anatomy Flowering plants
Bordered pits are very common in
(1) Gymnosperms
(2) Dicotyledons
(3) Pteridophytes
(4) Monocotyledons
Answer: (1) Gymnosperms
A pit possessing an extension of the secondary wall, i.e. a border, arching over part of the pit cavity is called bordered pit. Bordedred pits mainly occur in vessel elements, tracheids and fibres in gymnosperm xylem.
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Structural Organisation in Animals
Lamina propria is related to
(1) Human intestine
(2) Mammalian liver
(3) Graffian follicles
(4) Pancreatic acini
Answer: (1) Human intestine
Lamina propria is a layer of loose connective tissue in the mucosa of gut wall, which houses the bases of glands and contains blood and lymph vessels.
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Cockroach
In cockroach, the outer border of a tergum bends downward to become attached with
(1) Sternum
(2) Muscles
(3) Pleuron
(4) Mesenteries
Answer: (3) Pleuron
Pleuron is the name given to the lateral part of the cuticle in each segment of a cockroach.
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Structure of a Cell
Prokaryotic genetic system contains
(1) DNA and histones
(2) DNA but no histones
(3) Neither DNA nor histones
(4) Either DNA or histones
Answer: (2) DNA but no histones
Histones are not found in association with the DNA of prokaryotes.
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Biomolecules
The plant ash is an indication of
(1) Mineral salts absorbed by the plant
(2) Organic matter of the plant
(3) Both the mineral salts and organic matter
(4) None of the above
Answer: (1) Mineral salts absorbed by the plant
Plant ash is an indication of mineral salts absorbed by the plant. On heating dry plant or a plant part at 600$^o$ C in a crucible, the organic matter dissociates. The ash, which is left, contains oxides and carbonates of elements. About 60 elements have been reported from plant ashes. Out of these, 30 are present in all plants. Again out of these 30, 16 are essential, rest are nonessential.
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Cell cycle
Amitosis is
(1) Cleavage of the nucleus without recognisable chromosomes
(2) A division of chromosomes
(3) An indefinite division of chromosomes
(4) Chromosomes are present at the bridge
Answer: (1) Cleavage of the nucleus without recognisable chromosomes
Amitosis is an unusual process of nuclear division in which the nucleus is pinched into two by a constriction. The details of how it occurs are uncertain. Amitosis occurs in some protozoans ( including the macromolecules of the Ciliata) and in the embryonic membranes.
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Transport in Plants
Active absorption of water from the soil by the root is mainly affected by
(1) Respiratory activity of the root
(2) Tension on cell sap due to transpiration
(3) Tissue organisation
(4) None of the above
Answer: (1) Respiratory activity of the root
Active absorption of water from the soil by the roots involves an expenditure of metabolic energy, which comes from the respiring cells of the root.
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Mineral Nutrition in plants
An essential element is one which
(1) Is present in plant ash
(2) Is available in soil
(3) Is indispensable for growth
(4) Improves plants growth
Answer: (3) Is indispensable for growth
An essential element is one, which is indispensable for growth. D.I. Arnon and P.R. Stout gave criteria of essentiality of an element in 1939.
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Photosynthesis in Higher Plants
If a photosynthesising plant releases oxygen containing more than the normal amount of $^{18}$O, it is concluded that the plant has been supplied with
(1) $C_6H_{12}O_6$ containing $^{18}$O
(2) $H_2O$ containing $^{18}$O
(3) $CO_2$ containing $^{18}$O
(4) Oxygen in the form of ozone
Answer: (2) $H_2O$ containing $^{18}$O
In 1940 Sam Ruben used an isotope of oxygen, $^{18}$O to find out where the oxygen atoms went in photosynthesis. Ruben fed plants water-containing $^{18}$O but because $^{18}$O is not a radioactive isotope of the most common form of oxygen, $^{16}$O. Ruben used a mass spectrometer to determine the fate of the $^{18}$O. The $^{18}$O was found in the oxygen gas produced by the plant and none in the glucose formed.
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Respiration in Higher Plants
Respiration is a process in which
(1) Energy is stored in the form of ADP
(2) Energy is released and stored in the form of ATP
(3) Energy is not released at all
(4) Energy is used up
Answer: (2) Energy is released and stored in the form of ATP
Cellular respiration is energy releasing enzymatically controlled catabolic process, which involves a step-wise oxidative breakdown of organic substances inside living cells.
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Plant Growth & Development
Which one of the following nutrients is concerned with the growth of the plants in view of their role in synthesis of auxin?
(1) S
(2) Mn
(3) Zn
(4) K
Answer: (3) Zn
Zinc is essential for the synthesis of tryptophan-a precursor of auxins.
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Digestion and Absorption
Another term for digestion is
(1) Dehydration synthesis
(2) Hydrolysis
(3) Absorption
(4) Assimilation
Answer: (2) Hydrolysis
Digestion is the process of breaking down of the covalent bonds in the organic food molecules (Carbohydrates, lipids, proteins and nucleic acids) by hydrolysis. It is catalysed by digestive enzymes. The simpler and smaller molecules thus produced can then get entry into the surrounding cells.
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Breathing & Exchange of Gases
The gas-exchange surfaces of larger aquatic animals are
(1) Tracheae
(2) Malphigian tubules
(3) Gills
(4) Book lungs
Answer: (3) Gills
Typically gills are respiratory structures in aquatic animals (both vertebrates and invertebrates). Gills possess a large surface area for extensive gas exchange.
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Body Fluids and circulation
In the sinuses of an open circulatory system, blood is NOT segregated from the
(1) Cytoplasm
(2) Interstitial fluid
(3) Digestive cavity
(4) Urine
Answer: (2) Interstitial fluid
When the blood does not remain confined to the blood vessels and flows into spaces and channels, called lacunae and sinuses in the tissues, it is termed as the open circulatory system. The open circulatory system is common to molluscs and arthropods.
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Excretory products and their elimination
A nephridium of an earthworm drains materials directly from the
(1) Gut
(2) Coelom
(3) Lymph
(4) Blood
Answer: (2) Coelom
In Annelids like Nereis, earthworm, leech, etc., the tubular coiled structures, the nephridia are excretory organs, which drains materials directly from the coelom.
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Locomotion and Movement
Axial skeleton in man is made up of
(1) 126 bones
(2) 100 bones
(3) 103 bones
(4) 80 bones
Answer: (4) 80 bones
The axial skeleton consists of the skull, the spine, the ribs and the sternum (breastbone) and includes 80 bones.
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Neural control and Coordination
Nerve cells are devoid of
(1) Nucleus
(2) Sarcolemma
(3) Axon
(4) Cytoplasm
Answer: (2) Sarcolemma
The sarcolemma is the name of the cell membrane of a muscle fibre or muscle cell.
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Chemical Coordination
Which of the following hormones is a modified amino acid ?
(1) Prostaglandin
(2) Estrogen
(3) Epinephrine
(4) Progesterone
Answer: (3) Epinephrine
The hormones epinephrine and norephinephrine secreted by the adrenal medulla and thyroxine by thyroid gland are derived from the amino acid tyrosine.
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Reproduction in Organisms
In which of the following grafting is extremely useful?
(1) Citrus
(2) Apples
(3) Rubber
(4) All of these
Answer: (4) All of these
Grafting is routinely used for the propagation of rubber, apple, citrus,pear, mango and guava.
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Sexula Reproduction in Flowering Plants
Scion is a term in relation to
(1) Layering
(2) Cutting
(3) Grafting
(4) Micropropagation
Answer: (3) Grafting
Scion is a portion of a plant, usually a piece of young stem, which is inserted into a rooted stock in grafting.
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Human Reproduction
Oviparity is typically found in
(1) Whale
(2) Bat
(3) Penguin
(4) Mouse
Answer: (3) Penguin
Oviparity is the production of undeveloped eggs, which are laid or spawned by the female.
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Principles of Inheritance and Variation
Mendel was born in
(1) Austria
(2) Germany
(3) Britain
(4) Sweden
Answer: (1) Austria
Gregor Mendel was born in Heinzendorf, Austria on July 22,1822.
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Molecular basis of Inheritance
The first undoubted evidence about DNA being the genetic materiall came from
(1) Transformation of rough coated strain of Diplococcus pneumoniae into smooth coated strain
(2) The establishmmennt of DNA as the chief chemical constituent of chromosomes
(3) The establishment of DNA is a self-replicating substance
(4) Transduction of bacteria by action of bacteriophage
Answer: (2) The establishmmennt of DNA as the chief chemical constituent of chromosomes
Transformation is a permanent genetic change induced in cell following incorporation of new DNA.
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Evolution
Believers of spontaneous generation theory assumed that
(1) Organisms arose from other organism
(2) Organism arose from air
(3) Organism arose abiogenetically
(4) Organism arose simultaneously
Answer: (3) Organism arose abiogenetically
According to Theories of spontaneous generation, life has originated from non-living matter abiogenetically, i.e. without the intervention of living things.
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Human Health and Diseases
Which one of the following diseases is due to an allergic reaction?
(1) Hay fever
(2) Enteric fever
(3) Skin cancer
(4) Goitre
Answer: (1) Hay fever
Hay fever. Inflammation in the nasal passage and eyes caused by an allergic reaction to flowers and their pollen and scent, also to dust.
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Strategies for Enhancement in Food Production
Mule is produced by
(1) Selection
(2) Inbreeding
(3) Interspecific hybridisation
(4) Cross-breeding
Answer: (3) Interspecific hybridisation
Mule refers to hybrid offspring of a male donkey and a female horse. Mules are usually sterile.
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Microbes in Human Welfare
Streptomyces fradiae produces
(1) Aureomycin
(2) Neomycin
(3) Terramycin
(4) Erythromycin
Answer: (2) Neomycin
Neomycin was first isolated in 1949 by the American microbiologist Selman Waksman from a strain of the bacterial species Streptomyces fradiaeSee Answer
Biotechnology: principles and Processes
Identify the vector suitable for cloning long DNA fragments
(1) Phage vector
(2) Bacterial plasmid
(3) Yeast plasmid
(4) Cosmids
Answer: (4) Cosmids
Cosmids are DNA vectors that allow the insertion of long fragments of DNA (up to 50 kbases).
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Biotechnology and its Application
What is true of plasmids ?
(1) They are found in viruses
(2) They are main parts of chromosomes
(3) They are widely used in gene transfer
(4) They contain genes for vital activities
Answer: (3) They are widely used in gene transfer
Plasmids are extra chromosomal circular DNA replicates independently. Plasmids that can get associated temporarily with nucleoid are known as episomes.
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Organisms and Populations
The plant life of a given region, habitat or geological stratum irrespective of the numerical strength of each species is called
(1) Vegetation
(2) Community
(3) Flora
(4) Population
Answer: (3) Flora
All the plant life normally present in a given habitat at a given time is called flora.
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Ecosystem
The pyramid of number of individuals per unit area in grassland ecosystem will be
(1) Erect
(2) Inverted
(3) Both (1) and (2)
(4) None of the above
Answer: (1) Erect
Pyramid of numbers show relationship between the numbers of primary producers and consumers of different orders. Examples: Upright pyramids of numbers-grassland ecosystem; cropland ecosystem. Inverted pyramid of numbers-Tree.
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Biodiversity and Conservation
The endangered largest living lemur Indri indri is found in
(1) Madagascar
(2) Mauritius
(3) Sri Lanka
(4) India
Answer: (1) Madagascar
The endangered largest living lemur Indri indri is found in Madagascar
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Environmental Issues
Gases referred to as "Green house gases" are
(1) $CO_2$, $O_2$, $NO_2$, $NH_3$
(2) Chlorofluorocarbons, $CO_2$, $NH_3$, $N_2$
(3) $CH_4$, $N_2$, $CO_2$, $NH_3$
(4) Chlorofluorocarbons, $CO_2$, $CH_4$, $NO_2$
Answer: (4) Chlorofluorocarbons, $CO_2$, $CH_4$, $NO_2$
Greenhouse gases. Atmopheric gases such as carbon dioxide, methane, chlorofluorcarbons,nitrous oxides, ozone and water vapour that slow the passage of re-radiated heat through the Earth's atmosphere by absorbing infrared radiation.
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Living World
The system of plant classification proposed by Carolus Linnaeus was artificial because
(1) It is based on evolutionary relationship of plants
(2) It is based on similarities and differences in floral and other morphological characters only
(3) It took into account the physiological facts along with the morphological characters
(4) None of the above
Answer: (2) It is based on similarities and differences in floral and other morphological characters only
Linnaeus was the first to recognise the significance of flower and fruit structure. This system of classification is mainly based on the number, size and union of stamens and carpels, so this system is often called sexual system of classification.
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Biological Classification
The Gram's stain used for bacterial staining
(1) Safranin and iodine
(2) Crystal violet and cotton blue
(3) Cotton blue and iodine
(4) Crystal violet and iodine
Answer: (4) Crystal violet and iodine
Differential staining procedures divide bacteria into separate groups based on staining properties. The Gram stain, developed in 1884 by the Danish physician Christian Gram, is the most widely employed staining method in bacteriology. It is a differential staining procedure because it divides bacteria into two classes: Gram-negative and Gram-positive. In the first step of the Gram staining procedure, the smear is stained with the basic dye crystal violet. It is followed by the treatment with an iodine solution functioning as a mordant. That is, the iodine increases the interaction between the cell and the dye so that the cell is stained strongly. The smear is next stained decolourised by washing with alcohol or acetone. Gram-positive bacteria retain the crystal violet, whereas Gram-negative bacteria lose their crystal violet and become colourless. Finally, the smear is counterstained with safranin. Safranin colours Gram-negative bacteria pink to red and leave Gram-positive bacteria dark purple.
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Plant Kingdom
When two mature cells of Chlamydomonas fuse together it is known as
(1) Homogamy
(2) Hologamy
(3) Syngamy
(4) Autogamy
Answer: (2) Hologamy
Condition of having gametes similar to somatic cells or fusion between mature individuals of a species is called hologamy.
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Animal Kingdom
A species of Amoeba is called 'proteus' because it
(1) Has abundance of proteins
(2) Constantly changes its body shape
(3) Does not change its body shape
(4) Has protoplasm
Answer: (2) Constantly changes its body shape
The name Amoeba proteus has been derived from two Greek words Amoeba from amoibe, which means change and proteus after the name of the mythical sea-god Proteus, who could change shape.
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Morphology of Flowering Plants
Partial root parasite is
(1) Santalum
(2) Loranthus
(3) Viscum
(4) Cuscuta
Answer: (1) Santalum
Sandalwood tree (Santalum album) is an example of partial root parasite found abundantly in karnataka.
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Anatomy of Flowering Plants
The meristem in the roots is
(1) Terminal
(2) Intercalary
(3) Absent
(4) Sub-terminal
Answer: (4) Sub-terminal
The meristem in the root is subterminal because it is covered by the root cap.
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Structural Organisation in Animals
The cells forming the peritoneal lining of the coelom comprise the
(1) Squamous epithelium
(2) Columnar epithelium
(3) Glandular epithelium
(4) Ciliated epithelium
Answer: (1) Squamous epithelium
The peritonium is thin membrane that lines the abdominal and pelvic cavities and covers most abdominal viscera. It is composed of layer of mesothelium supported by a thin layer of connective tissue.
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Cockroach
Which one of the following regions of the alimentary canal in Periplaneta is characterised by the presence of a peritrophic membrane?
(1) Mesenteron
(2) Crop
(3) Gizzard
(4) Ileum
Answer: (1) Mesenteron
The internal lining of the wall of midgut or mesenteron in cockroach is an endodermal epithelium of columnar cells. The epithelium is internally covered, not by a cuticle, but by a thin transparent peritrophic membrane formed of chitin and protein.
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Structure of a Cell
Prokaryotic cell is one, which does not have
(1) Proper nucleus
(2) Endoplasmic reticulum & Mitochondria
(3) Proper nucleus and most of cell organelles
(4) Cell Wall
Answer: (3) Proper nucleus and most of cell organelles
Prokaryote is an organism in which the genetic material is not enclosed in a cell nucleus. Bacteria are prokaryotes.
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Biomolecules
Which of the following micronutrients has a role in electron transport and chlorophyll synthesis?
(1) Chlorine
(2) Zinc
(3) Manganese
(4) Iron
Answer: (4) Iron
Iron is constituent of ferredoxin and cytochromes; required for synthesis of chlorophyll.
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Cell Cycle
Histone proteins are synthesized in
(1) M-phase
(2) S-phase
(3) G$_1$ phase
(4) G$_2$ phase
Answer: (2) S-phase
Histone is a protein associated with nucleic acid in chromatin of eukaryotic cells. Histones are characterised by high levels of the basic amino acids arginine and lysine. Histones are not found in association with the DNA of prokaryotes. The bulk of the histones are synthesised during S phase of the cell cycle.
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Transport in Plants
What is the most suitable temperature for absorption of water by root hairs?
(1) 40-45$^o$ C
(2) 20-35$^o$ C
(3) 5-10$^o$ C
(4) 10-15$^o$ C
Answer: (2) 20-35$^o$ C
The optimum temperature for water absorption is between 20$^o$ C to 35$^o$ C
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Mineral Nutrition in Plants
Which one of the following essential elements can land plants normally take exclusively or directly from the air?
(1) Carbon
(2) Nitrogen
(3) Phosphorous
(4) Hydrogen
Answer: (1) Carbon
Plants obtain carbon from carbon dioxide in the atmosphere, oxygen and hydrogen primarily from the water they take in through their roots; nitrogen from mainly biologically fixed ions present in the soil and their other nutrients from the soil.
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Photosynthesis in Higehr plants
The maximum evolution of oxygen is by
(1) Crops
(2) Phytoplanktons of the sea
(3) Forests
(4) Great land area
Answer: (2) Phytoplanktons of the sea
Algae of oceans carry out nine-tenth of all photosynthesis of the world.
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Respiration in Plants
The energy yield as a result of total oxidation of 1 glucose molecule during cellular respiration is to convert
(1) 34 molecules of ADP into 34 molecules of ATP
(2) 30 molecules of ADP into 30 molecules of ADP
(3) 38 molecules of ADP into 38 molecules of ATP
(4) 32 molecules of ADP into 32 molecules of ADP
Answer: (3) 38 molecules of ADP into 38 molecules of ATP
Oxidation of one molecule of glucose in aerobic respiration results in the formation of 38 ATP molecules. In most eukaryotic cells 2 ATP molecules are consumed in transporting 2 NADH produced during glucolysis, into the mitochondria for further oxidation. Thus, in such cells, there is net gain of 36 ATP instead of 38 ATP molecules.
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Plant Growth and Development
Leaf fall occurs when the content of
(1) Auxin increases
(2) Auxin decreases
(3) Abscisic acid decreases
(4) Gibberellic acid decreases
Answer: (2) Auxin decreases
Auxin is a controlling factor in abscission. Reduction in the auxin content in leaves and fruits results in their abscission. Application of auxin like 2,4-D, IAA, NAA to the leaves and fruits prevent their premature falling
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Digestion and Absorption
The main function of prolonged chewing is to rupture
(1) Membranes
(2) Cell Wall
(3) Connective tissues
(4) Muscle bundle
Answer: (2) Cell Wall
Chewing is especially important for most fruits and raw vegetables, because these have indigestible cellulose wall around their nutrient portions, which must be broken, before enzymes can act upon the food.
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Respiration in Animals
Carbonic anhydrase is present in high concentration in
(1) Plasma
(2) Erythrocytes
(3) Leucocytes
(4) Neurons
Answer: (2) Erythrocytes
Carbonic anhydrase is an enzyme, present in red blood cells. It catalyses the reaction between carbon dioxide and water to form carbonic acid, which subsequently dissociates. This reaction is one of the fastest known and controls the elimination of carbon dioxide from the body and the pH of urine. It also facilitates the transfer of carbon dioxide from the tissues to the blood and from the blood to the alveoli (air sacs) of the lungs.
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Body Fluids and Circulation
In which of the following groups of animal the heart pumps only deoxygenated blood
(1) Fishes
(2) Reptile
(3) Birds
(4) Amphibians
Answer: (1) Fishes
In fishes, heart is two chambered with an auricle and ventricle; it receives venous blood only and pumps blood to gills only for oxygenation. Hence, referred to as the venous heart or branchial heart.
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Excretory Products and their Elimination
In the Ornithine cycle, the enzyme arginase breaks down arginine into
(1) Citrulline and Urea
(2) Ornithine and Ammonia
(3) Ornithine and Urea
(4) Citrulline and Ammonia
Answer: (3) Ornithine and Urea
The enzyme arginase catalyses the hydrolysis of arginine to ornithine and urea and is important in the urea cycle.
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Locomotion and Movement in Animals
Skull of man is made up of
(1) 10 bones
(2) 22 bones
(3) 30 bones
(4) 24 bones
Answer: (2) 22 bones
The skull of man is made up of 22 bones of varying shapes and sizes. The cranium consists of eight flat plate-like bones that surround and protect the brain. Some of these contribute to the formation of the facial skeleton. The remaining 14 bones, including the mandible, form the face. The mandible is the only movable bone in the skull; the rest are connected by immovable joints called sutures.
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Neural Control and Coordination
The interstitial tissue of nervous tissue is
(1) Satellite cells
(2) Neuroglia
(3) Schwann cells
(4) All of the above
Answer: (2) Neuroglia
Neuroglia are supporting cells, which form packing around the neurons. There are present three types of neuroglia: astrocytes, oligodendrocytes and microgliocytes.
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Chemical Control and Coordination
Most of the steroid hormones are synthesised from
(1) Insulin
(2) Tyrosine
(3) Glycogen
(4) Cholesterol
Answer: (4) Cholesterol
The hormones secreted by the adrenal cortex, testes, ovaries and placenta are composed of steroids.
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Reproduction in Organisms
Apomixis in plant means development of a plant
(1) From root cuttings
(2) Without fusion of gametes
(3) From fusion of gametes
(4) From stem cutting
Answer: (2) Without fusion of gametes
Apomixis is a form of asexual reproduction, including vegetative propagation. The term is very often used in narrower sense to mean the production of seeds without fertilisation. In this restricted sense the term is synonymous with agamospermy. An apomictic plant is an organism, which chiefly reproduces this way. Apomixis is a natural way of cloning plants through seed. It offers plant breeders a unique system for developing new and distinctive cultivars in many species. Apomixis is widespread among several plant families including Gramineae, Compositae and Rosaceae.
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Sexual Reproduction in Flowering Plants
Which of the following is propagated by means of cuttings?
(1) Sugarcane
(2) Coffee
(3) Citrus
(4) All of these
Answer: (4) All of these
Cuttings are small pieces of stem, root or leaves which when placed in the soil can sprout to form new plants. Stem cuttings are commonly used in sugarcane, coffee, citrus, tea, Duranta, Rosa and Clerodendron.
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Human Reproduction
Each ejaculate of a man contains about how many sperm ?
(1) 200
(2) 2000
(3) 200,000
(4) 200,000,000
Answer: (4) 200,000,000
The normal human male usually produces 200,000,000 sperms per ejaculation, assuring an adequate number for fertilisation to take place. Fewer than 100 ever reach the vicinity of the egg. However only one sperm normally enters an egg.
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Reproductive Health
In reproduction of a test tube baby
(1) Fertilisation is done outside body
(2) Foetus is grown in a test tube
(3) Fertilisation is done inside body
(4) None of these
Answer: (1) Fertilisation is done outside body
Patient's eggs and her partner's sperm are collected and mixed together in a laboratory to achieve fertilisation outside the body. The embryos produced may then be transferred into the female patient.
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Principles of Inheritance and Variation
In F$_2$ generation of monohybrid cross the cause of 1:2:1 phenotypic raio is
(1) Epistatics
(2) Inhibition
(3) Quantitative Inheritance
(4) Incomplete Dominance
Answer: (4) Incomplete Dominance
Incomplete dominance in Mirabilis jalapa (four-O' clock plant) was reported by Carl Correns in 1905.
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Molecular Basis of Inheritance
The DNA is the genetic material was proved conclusively by
(1) J.D. Watson
(2) Hershey and Chase
(3) Alfred Griffith
(4) Boveri and Sutton
Answer: (2) Hershey and Chase
Alfred Day Hershey was awarded the Nobel Prize in 1969 for the famous "blender's experiment". Hershey and his assistant Martha Chase showed that only DNA and not protein, was injected into a bacterial cell by an infecting phage particle. The DNA was sufficient to transfer to the bacteria all the genetic information needed to produce more phage.
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Evolution
A fossil is a
(1) Laboratory preserved animal
(2) Dead animal of the past
(3) Inorganic relic of the past
(4) Stuffed animal
Answer: (2) Dead animal of the past
Fossil is the remains or traces of any organism that lived in the geological past. In general only the hard parts of organisms become fossilized (e.g., bones, teeth, shells and wood) but under certain circumstances the entire organism is preserved.
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Human Health and Disease
Messenger molecules, released by virus infected cells that bind to the surfaces of healthy cells and stimulate them to synthesise proteins that prevent viral reproduction are called
(1) Interferons
(2) Cytotoxins
(3) Antibiotics
(4) Anticancer protein
Answer: (1) Interferons
Interferons are a group of proteins called cytokines produced by white blood cells, fibroblasts, or T-cells as part of an immune response to a viral infection or other immune trigger. The name of the proteins comes from their ability to interfere with the production of new viral particles.
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Strategies for Enhancement in Food Production
Plants protect themselves from fungi by producing
(1) Protoxins
(2) Phytoalexins
(3) Prolactins
(4) All the above
Answer: (2) Phytoalexins
Phytoalexins are low molecular weight antimicrobial compounds produced by plants after infection or metabolic stress. They are part of a plant's multicomponent response mechanism for disease resistance and the speed and magnitude of their accumulation is important in determining disease resistance to fungal and bacterial diseases.
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Microbes in Human Welfare
Which group is responsible for formation and flavour of yoghurt?
(1) Bacillus megaterium and Xanthomonas sp.
(2) Bacillus subtilis and E.coli
(3) Rhizobium meliloti and Azotobacter
(4) Lactobacillus casei and Streptococcus thermophilus
Answer: (4) Lactobacillus casei and Streptococcus thermophilus
Yoghurt is a fermented dairy product made by adding bacterial cultures to milk, which causes the transformation of the milk's sugar, lactose into lactic acid. This process gives yoghurt its refreshingly tart flavour and unique pudding-like texture.
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Biotechnology: Principles and processes
Extensively used tool in genetic engineering of crop plants is
(1) Agrobacterium tumefaciens
(2) Protoplasm fusion
(3) Transposons
(4) Microinjection
Answer: (1) Agrobacterium tumefaciens
Plant transformation mediated by Agrobacterium tumefaciens, a soil plant pathogenic bacterium, has become the most used method for the introduction of foreign genes into plant cells and the subsequent regeneration of transgenic plants.
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Biotechnology and its Applications
Biopiracy is related to which of the following?
(1) Traditional knowledge
(2) Biomolecules and regarding bioresources, genes isolated from bioresources
(3) Bioresources
(4) All the above
Answer: (4) All the above
Biopiracy refers to the exploitation, through use of biopatents of bioloical resources or bioresources of other nations without proper authorisation from the countries concerned.
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Organisms and Populations
Noosphere is the term used for
(1) The Environment
(2) The Biosphere
(3) The Natural Ecosystem
(4) A Community
Answer: (2) The Biosphere
Noosphere is referred to a human-dominated environment. It is another name that has been given to the biosphere since man has changed it from a naturally self-sufficient system to a system of resources for himself.
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Ecosystem
The ecology of individual organisms or species is called
(1) Synecology
(2) Autecology
(3) Habitat ecology
(4) Population ecology
Answer: (2) Autecology
Autecology is the study of an individual species in its environment.
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Biodiversity and Conservation
Red Data Book provides data on
(1) Biota of Red Sea
(2) Effect of red light on photosynthesis
(3) Red pigmented plants
(4) Threatened species
Answer: (4) Threatened species
Red Data Book: A catalogue published by the International Union for the Conservation of Nature and Natural Resources (IUCN) that lists rare species and those in danger of extinction.
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Environmental Issues
Exposure of plants to high fluoride concentration results in necrosis or chlorosis characteristic in
(1) Petiole but not in lamina
(2) Leaf tip and leaf margins
(3) Stem tips only
(4) Mid rib and Lamina
Answer: (2) Leaf tip and leaf margins
Exposure of plants to high fluoride concentration results in chlorosis and necrosis at the tips and margins of leaves.
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Digestion and Absorption
A bolus is
(1) A mass of crushed food moistened with saliva
(2) The semisolid material resulting from partial digestion in the stomach
(3) The milky emulsified fat absorbed from small intestine
(4) Indigestible materials that helps in movement and absorption
Answer: (1) A mass of crushed food moistened with saliva
A bolus is a ball of chewed food bound together with saliva that is formed in the mouth by the action of the tongue. The bolus is shaped to a size that allows it to pass into the oesophagus after being swallowed.
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Breathing and Exchange of gases
Vocal cords occur in
(1) Pharynx
(2) Glottis
(3) Bronchial tube
(4) Larynx
Answer: (4) Larynx
Larynx is an organ, situated at the front of the neck above the windpipe, which contains the vocal cords, responsible for the production of vocal sounds.
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Body Fluids and Circulation
The cells constituting walls of the blood capillaries are known as
(1) Parietal cells
(2) Haemocytes
(3) Oxyntic cells
(4) Endothelial cells
Answer: (4) Endothelial cells
The cells constituting walls of the blood capillaries are known as endothelial cells.
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Excretory Products and their Elimination
Which of the following is the part of kidney?
(1) Pelvis
(2) Ileum
(3) Seminiferous tubules
(4) Cystic duct
Answer: (1) Pelvis
The human kidney measures about 10 cm in length, about 5 cm in breadth and about 9 cm in thickness. On the concave side of the kidney, there is a longitudinal opening called the hilum and to this area the blood vessels, nerves and ureter join kidneys at extensive, flat, funnel shaped space called the renal pelvis.
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Locomotion and movement
Foramen magnum is found on
(1) Lateral side of skull
(2) Neural canal
(3) Anterior side of skull
(4) Posterior side of skull
Answer: (4) Posterior side of skull
Foramen magnum is the large opening at the hind-end of a vertebrate skull through which the spinal cord passes to the brain.
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Neural control and coordination
The largest number of cell bodies of neurons in our body is found in
(1) Brain
(2) Spinal cord
(3) Tongue
(4) Retina
Answer: (1) Brain
The adult human brain contains more than a thousand million neurons. It has been estimated that in the cerebral cortex alone.
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Chemical coordination
Hypothalamic releasing hormones reach the anterior pituitary gland by way of
(1) The posterior pituitary gland
(2) Lymphatic vessels
(3) Blood vessels
(4) Axons
Answer: (3) Blood vessels
Neurons in the hypothalamus secrete releasing hormones into veins that carry the releasing hormones directly to the vessels of the adenohypophysis. Thus by-passing the normal circulatory route
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Some Basic Concepts of Chemistry
What is the weight of oxygen required for the complete combustion of 2.8 kg of ethylene?
(1) 2.8 kg
(2) 6.4 kg
(3) 9.6 kg
(4) 96 kg
Answer: (3) 9.6 kg
$C_2H_4(28g) + 3O_2(96g) → 2CO_2 + 2H_2O $
For complete combustion,
2.8 kg of $C_2H_4$ requires = $\frac{96}{28} × 2.8 × 10^3$ g = $9.6 × 10^3$ g = 9.6 kg of $O_2 $
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Structure of Atom
$Be^{2+}$ is isoelectronic with which of the following ions?
(1) $H^+ $
(2) $Li^+ $
(3) $Na^+ $
(4) $Mg^{2+} $
Answer: (2) $Li^+ $
Species - No. of electrons
$Be^{2+}$ - 2
$H^+$ - 0
$Li^+$ - 2
$Na^+$ - 10
$ Mg^{2+}$ - 10 See Answer
Classfification of Elements & Periodicity in Properties
The element Z = 114 has been discovered recently. It will belong to which of the following family/group and electronic configuration?
Answer: (1) Carbon family, $[Rn] 5f^{14} 6d^{10} 7s^2 7p^2$
The electronic configuration of the element with Z = 114 (Flerovium) is $[Rn] 5f^{14} 6d^{10} 7s^2 7p^2$.Hence, it belongs to carbon family which has the same outer electronic configuration.
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Chemical Bonding & molecular Structure
Which of the following, set of molecules will have zero dipole moment?
Which one of the following is the correct order of interactions?
(1) Covalent $<$ hydrogen bonding $<$ van der Waals’ $<$ dipole-dipole
(2) van der Waals’ $<$ hydrogen bonding $<$ dipole-dipole $<$ covalent
(3) van der Waals’ $<$ dipole-dipole $<$ hydrogen bonding $<$ covalent
(4) Dipole-dipole $<$ van der Waals’ $<$ hydrogen bonding $<$ covalent.
Answer: (2) van der Waals’ $<$ hydrogen bonding $<$ dipole-dipole $<$ covalent
The strength of interaction follows the order : van der Waals’ $<$ hydrogen-bonding $<$ dipole-dipole $<$ covalent. It is so because bond length of H-bond is larger than that of a covalent bond.And also covalent bond is strongest because, the greater the extent of overlapping, the stronger is the bond formed.
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Thermodynamics
In a closed insulated container a liquid is stirred with a paddle to increase the temperature, which of the following is true?
(1) $∆$E = W ≠ 0, q = 0
(2) $∆$E = W = q ≠ 0
(3) $∆$E = 0, W = q ≠ 0
(4) W = 0, $∆$E = q ≠ 0
Answer: (1) $∆$E = W ≠ 0, q = 0
The mathematical form of first law of thermodynamics : q = $∆$E + W Since the system is closed and insulated, q = 0 Paddle work is done on system. ∴ W ≠ 0. Temperature and hence internal energy of the system increases. ∴ $∆$E ≠ 0.
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Equilibrium
Given the reaction between 2 gases represented by $A_2$ and $B_2$ to give the compound $AB_{(g)}$.
$A_{2(g)}+B_{2(g)} ⇄ 2AB_{(g)}$
At equilibrium, the concentration of
$A_2=3.0×10^{-3}M$, of $B_2=4.2× 10^{-3}M$, of AB = 2.8 $×10^{-3}$M
If the reaction takes place in a sealed vessel at 527°C, then the value of $K_C$ will be
Answer: (2) Both oxidation and reduction
Redox reactions are those chemical reactions which involve both oxidation and reduction simultaneously.
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Hydrogen
The method used to remove temporary hardness of water is
(1) synthetic resins method
(2) Calgon’s method
(3) Clark’s method
(4) ion-exchange method.
Answer: (3) Clark’s method
Clark’s process is used to remove temporary hardness of water. In this method quick lime is added. The bicarbonates present in temporary hard water react with lime water to form insoluble calcium and magnesium carbonates which can be easily filtered off.
$Cao+H_2O → Ca(OH)_2$
$Ca(OH)_2 + Ca(HCO_3)_2 → 2CaCO_3 + 2H_2O$
$Mg(HCO_3)_2+2Ca(OH)_2 → 2CaCO_3 + Mg(OH)_2 + 2H_2O$
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The S-Block Elements
Ionic mobility of which of the following alkali metal ions is lowest when aqueous solution of their salts are put under an electric field?
(1) K
(2) Rb
(3) Li
(4) Na
Answer: (3) Li
The hydration enthalpy of alkali metal ions decreases with increase in ionic sizes i.e.,
$Li^+> Na^+>K^+>Rb^+>Cs^+$
Hence, lithium having maximum degree of hydration will be least mobile.
The order of ionic mobility is
$[Li_{(aq)}]^+> [Na_{(aq)}]^+>[K_{(aq)}]^+>[Rb_{(aq)}]^+$
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The p-Block Elements
The correct order of atomic radii in group 13 elements is
Organic Chemistry - Some Basic Principles & Techniques
An organic compound X(molecular formula $C_6H_7O_2N$) has six carbon atoms in a ring system, two double bonds and a nitro group as substituent, X is
(1) homocyclic but not aromatic
(2) aromatic but not homocyclic
(3) homocyclic and aromatic
(4) heterocyclic and aromatic.
Answer: (1) homocyclic but not aromatic
Hence, it is homocyclic (as the ring system is made of one type of atoms, i.e., carbon) but not aromatic.
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Hydrocarbons
Liquid hydrocarbons can be converted to a mixture of gaseous hydrocarbons by
(1) oxidation
(2) cracking
(3) distillation under reduced pressure
(4) hydrolysis
Answer: (2) cracking
The process of cracking converts higher alkanes into smaller alkanes and alkenes. This process can be used for production of natural gas.
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Environmental Chemistry
Which one of the following is not a common component of photochemical smog?
The pure crystalline substance on being heated gradually first forms a turbid liquid at constant temperature and still at higher temperature turbidity completely disappears. The behaviour is a characteristic of substance forming
(1) allotropic crystals
(2) liquid crystals
(3) isomeric crystals
(4) isomorphous crystals
Answer: (2) liquid crystals
Liquid crystals on heating first become turbid and then on further heating turbidity completely disappears.
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Solutions
How many g of dibasic acid (mol. weight 200) should be present in 100 mL of the aqueous solution to give strength of 0.1 N?
(1) 10 g
(2) 2 g
(3) 1 g
(4) 20 g
Answer: (3) 1 g
The strength of the solution is 0.1 N.
$\frac{w}{E}=\frac{V×N}{1000}$
Equivalent weight = 100
w = $\frac{100× 0.1× 100}{1000}$ = 1 g
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Electrochemistry
Consider the following relations for emf of an electrochemical cell
(i) EMF of cell = (Oxidation potential of anode) – (Reduction potential of cathode)
(ii) EMF of cell = (Oxidation potential of anode) + (Reduction potential of cathode)
(iii) EMF of cell = (Reductional potential of anode) + (Reduction potential of cathode)
(iv) EMF of cell = (Oxidation potential of anode) – (Oxidation potential of cathode)
Which of the above relations are correct?
(1) (iii) and (i)
(2) (i) and (ii)
(3) (iii) and (iv)
(4) (ii) and (iv)
Answer: (4) (ii) and (iv)
EMF of a cell = Reduction potential of cathode – Reduction potential of anode
= Reduction potential of cathode + Oxidation potential of anode
= Oxidation potential of anode – Oxidation potential of cathode.
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Chemical Kinetics
For a reaction between A and B the order with respect to A is 2 and the order with respect to B is 3. The concentrations of both A and B are doubled, the rate will increase by a factor of
Which one of the following characteristics is associated with adsorption?
(1) $∆$G and $∆$H are negative but $∆$S is positive.
(2) $∆$G and $∆$S are negative but $∆$H is positive.
(3) $∆$G is negative but $∆$H and $∆$S are positive.
(4) $∆$G, $∆$H and $∆$S all are negative.
Answer: (4) $∆$G, $∆$H and $∆$S all are negative.
As the molecules of the adsorbate are held on the surface of the solid adsorbent, entropy decreases i.e., $∆$S = –ve. As $∆$G = $∆$H – T$∆$S For the adsorption to occur, $∆$G = –ve and it is possible only if $∆$H = –ve.
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General Principles & Processes in Isolation of Elements
Roasting of sulphides gives the gas X as a byproduct. This is a colourless gas with choking smell of burnt sulphur and causes great damage to respiratory organs as a result of acid rain. Its aqueous solution is acidic, acts as a reducing agent and its acid has never been isolated. The gas X is
(1) its atom has a stable electronic configuration
(2) it has low atomic radius
(3) its electronegativity is fairly high
(4) dissociation energy of its molecule is fairly high
Answer: (4) dissociation energy of its molecule is fairly high
$N_2$ molecule contains triple bond between N atoms having very high dissociation energy (946 kJ mol$^{–1}$) due to which it is relatively inactive.
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The D & F - Block Elements
Which of the following pairs has the same size?
(1) $Fe^{2+}, Ni^{2+} $
(2) $Zr^{4+}, Ti^{4+}$
(3) $Zr^{4+}, Hf^{4+} $
(4) $Zn^{2+}, Hf^{4+}$
Answer: (3) $Zr^{4+}, Hf^{4+} $
$Hf^{4+}$ and $Zr^{4+}$ belong to group IVB. But, $Hf^{4+}$ has same size as $Zr^{4+}$ due to the addition of 14 lanthanide elements before it in which electrons are added into the f-subshell which poorly shield the outer electrons and contraction in size occurs.
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Coordination Compounds
Which of the following ligands is expected to be bidentate?
(1) $CH_3NH_2$
(2) $CH_3CN$
(3) Br
(4) $C_2O_4^{2-}$
Answer: (4) $C_2O_4^{2-}$
When a ligand has two groups that are capable of bonding to the central atom, it is said to be bidentate. Thus, the only ligand,which is expected to be bidentate is $C_2O_4^{2-}$
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Haloalkanes & Haloarenes
When chlorine is passed through propene at 400°C, which of the following is formed?
(1) PVC
(2) Allyl chloride
(3) Propyl chloride
(4) 1, 2-Dichloroethane
Answer: (2) Allyl chloride
$CH_3CH=CH_2+Cl_2-HCl → ClCH_2CH=CH_2$
At 400°C temperature, substitution occurs instead of addition.
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Alcohols, Phenols & Ethers
When vapours of a secondary alcohol is passed over heated copper at 573 K, the product formed is
The oxidation of toluene to benzaldehyde by chromyl chloride is called
(1) Etard reaction
(2) Riemer–Tiemann reaction
(3) Wurtz reaction
(4) Cannizzaro’s reaction
Answer: (1) Etard reaction
The oxidation of toluene ($C_6H_5CH_3$) with chromyl chloride ($CrO_2Cl_2$) in $CCl_4$ or $CS_2$ to give benzaldehyde is called Etard reaction. In this reaction, the chromyl chloride first forms a brown complex, which is separated and then decomposed with $H_2O$ to give benzaldehyde ($C_6H_5CHO$).
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Amines
Which of the following reactions is appropriate for converting acetamide to methanamine?
(1) Hoffmann hypobromamide reaction
(2) Stephen’s reaction
(3) Gabriel phthalimide synthesis
(4) Carbylamine reaction
Answer: (1) Hoffmann hypobromamide reaction See Answer
Biomolecules
Which one given below is a non-reducing sugar?
(1) Glucose
(2) Sucrose
(3) Maltose
(4) Lactose
Answer: (2) Sucrose
All monosaccharides whether aldoses or ketoses are reducing sugars. Disaccharides such as sucrose in which the two monosaccharide units are linked through their reducing centres i.e., aldehydic or ketonic groups are non-reducing.
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Polymers
Natural rubber has
(1) alternate cis- and trans-configuration
(2) random cis- and trans-configuration
(3) all cis-configuration
(4) all trans-configuration
Answer: (3) all cis-configuration
Natural rubber is cis-polyisoprene.
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Chemistry in Everyday Life
Mixture of chloroxylenol and terpineol acts as
(1) antiseptic
(2) antipyretic
(3) antibiotic
(4) analgesic
Answer: (1) antiseptic
Dettol which is a well known antiseptic is a mixture of chloroxylenol and a-terpineol in a suitable solvent.
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Biomolecules
Fructose reduces Tollens’ reagent due to
(1) asymmetric carbons
(2) primary alcoholic group
(3) secondary alcoholic group
(4) enolisation of fructose followed by conversion to aldehyde base
Answer: (4) enolisation of fructose followed by conversion to aldehyde base
Under alkaline conditions of the reagent, fructose gets converted into a mixture of glucose and mannose (Lobry de Bruyn van Ekenstein rearrangement) both of which contain the –CHO group and hence, reduce Tollens’ reagent to give silver mirror test.
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