Sunday, 4 June 2017

THREE EQUATIONS OF MOTION
The three equations of motion v = u + at ; s = ut + (1/2) at2 and v2 = u2 + 2as can be derived with the help of graphs as described below.
1. Derive v = u + at by Graphical Method
Consider the velocity – time graph of a body shown in the below Figure.Velocity–Time graph to derive the equations of motion.
The body has an initial velocity u at point A and then its velocity changes at a uniform rate from A to B in time t. In other words, there is a uniform acceleration 'a' from A to B, and after time t its final velocity becomes 'v' which is equal to BC in the graph. The time t is represented by OC. To complete the figure, we draw the perpendicular CB from point C, and drawAD parallel to OCBE is the perpendicular from point Bto OE.
Now, Initial velocity of the body,u
=
OA...... (1)
And, Final velocity of the body, v
=
BC........ (2)
But from the graph BC
=
BD + DC
Therefore, v
=
BD + DC ......... (3)
Again DC
=
OA
So, v
=
BD + OA
Now, From equation (1), OA
=
u
So, v
=
BD + u ........... (4)
We should find out the value of BD now. We know that the slope of a velocity – time graph is equal to acceleration, a.
Thus, Acceleration, a
=
slope of line AB
or a
=
BD/AD
But AD
=
OC = t,
so putting t in place of AD in the above relation, we get:
a
=
BD/t
or BD
=
at
Now, putting this value of BD in equation (4) we get :
v
=
at + u
This equation can be rearranged to give:
v
=
u + at
And this is the first equation of motion. It has been derived here by the graphical method.
2. Derive s = ut + (1/2) at2 by Graphical Method
Velocity–Time graph to derive the equations of motion.
Suppose the body travels a distance s in time t. In the above Figure, the distance travelled by the body is given by the area of the space between the velocity – time graph AB and the time axis OC,which is equal to the area of the figure OABC. Thus:
Distance travelled
=
Area of figure OABC
=
Area of rectangle OADC + Area of triangle ABD
We will now find out the area of the rectangle OADCand the area of the triangle ABD.
(i) Area of rectangle OADC
=
OA × OC
=
u × t
=
ut ...... (5)
(ii) Area of triangle ABD
=
(1/2) × Area of rectangle AEBD
=
(1/2) × AD × BD
=
(1/2) × t × at (because AD = tand BD = at)
=
(1/2) at2...... (6)
So, Distance travelled, s
=
Area of rectangle OADC + Area of triangle ABD
or s = ut + (1/2) at2
This is the second equation of motion. It has been derived here by the graphical method.
3. Derive v2 = u2 + 2as by Graphical Method
Velocity–Time graph to derive the equations of motion.
We have just seen that the distance travelled s by a body in time t is given by the area of the figure OABCwhich is a trapezium. In other words,
Distance travelled, s
=
Area of trapezium OABC
Now, OA + CB = u + v and OC = t. Putting these values in the above relation, we get:
 ...... (7)
We now want to eliminate t from the above equation. This can be done by obtaining the value of t from the first equation of motion. Thus, v = u + at (First equation of motion)
And, at = v – u or 
Now, putting this value of t in equation (7) above, we get: 
or 2as
=
v2 – u2 [because (v + u) × (v – u) = v2 – u2]
or v2
=
u2 + 2as
This is the third equation of motion.

Wednesday, 24 May 2017

Biological Classification

Multiple Choice Questions
Single Correct Answer Type
Q1. All eukaryotic unicellular organisms belong to
(a) Monera (b) Protista (c) Fungi (d) Bacteria
Ans: (b) Monera—Kingdom of prokaryotes
• All eukaryotic unicellular organisms belong to protista.
Q2. The five kingdom classification was proposed by
(a) R.H. Whittaker . (b) C. Linnaeus
(c) A. Roxberg (d) Virchow
Ans: (a) This phylogenetic classification was proposed by R.H. Whittaker (1969). He created new kingdom ‘Fungi’. The five kingdom classification are as follows: 1. Plantae, 2. Animalia, 3. Protista. 4. Monera and 5. Fungi.
Whittaker has used 5 criteria for the 5 kingdom classification and are as follows:
1. Reproduction,
2. Cell structure,
3. Phylogenetic relationships,
4. Mode of nutrition,
5. Thallus organisation
Q3. Organisms living in salty areas are called as
(a) Methanogens (b) Halophiles
(c) Heliophytes (d) Thermoacidophiles
Ans: (b)
• Halophiles: Bacteria living in extremely salty areas.
• Thermoacidophiles: Bacteria living in hot springs/deep sea water.
E.g.: Thermococcus
• Methanogens: Bacteria living in marshy areas and produce methane gas.
• Heliophytes: Sun loving plants
Q4. Naked cytoplasm, multinucleated and saprophytic are the characteristics of
(a) Monerans (b) Protists (c) Fungi (d) Slime moulds
Ans: (d) Slime moulds are saprophytic protists, without cell walls. The spores
of slime moulds possess true walls. Thalloid multinucleate body of a slime mould is called plasmodium. Spores are dispersed by air currents.
E.g.: Acellular slime mould—Physarum, Cellular slime mould—Dictyostelium.
Q5. An association between roots of higher plants and fungi is called .
(a) Lichen (b) Fern (c) Mycorrhiza (d) BGA
Ans: (c) Lichens are symbiotic associations, i.e. mutually useful associations, between algae and fungi. This relationship is best known as helotism.
Q6. A dikaryon is formed when
(a) Meiosis is arrested
(b) The two haploid cells do not fuse immediately
(c) Cytoplasm does not fuse
(d) None of the above
Ans: (b) In some fungi the fusion of two haploid cells immediately results in diploid cells (2n). However, in other fungi (ascomycetes and basidiomycetes), an intervening dikaryotic stage (n + n, i.e. two nuclei per cell) occurs. Such a condition is called a dikaryon and the phase is called dikaryophase of fungus. A dikaryotic cell has two dissimilar haploid nuclei.
Q7. Contagium vivum fluidum was proposed by
(a) D. J. Ivanowsky (b) M. W. Beijerinck
(c) Stanley (d) Robert Hooke
Ans: (b) D.J. Ivanowsky (1892) discovered the virus and has recognised certain microbes as causal organism of the mosaic disease of tobacco. M.W. Beijerinck (1898) demonstrated that the extract of the infected plants of tobacco could cause infection in healthy plants and called the fluid as Contagium vivum fluidum (infectious living fluid). W. M. Stanley (1935) first time showed that viruses could be crystallised and crystals consist largely of proteins.
Q8. Association between mycobiont and phycobiont are found in
(a) Mycorrhiza (b) Root (c) Lichens (d) BGA
Ans. (c) Association between mycobiont and phycobiont are found in lichens.
Q9. Difference between virus and viroid is
(a) Absence of protein coat in viroid but present in virus
(b) Presence of low molecular weight RNA in virus but absent in viroid
(c) Both (a) and (b)
(d) None of the above
Ans: (a) Viroids are smaller than viruses and the cause of potato spindle tuber disease, chrysanthemum stunt disease. It was found to be a free RNA and lacked the protein coat that is found in viruses, hence the name viroid.
Q10. With respect to the fungal sexual cycle, choose the correct sequence of events.
(a) Karyogamy, plasmogamy and meiosis
(b) Meiosis, plasmogamy and karyogamy
(c) Plasmogamy, karyogamy and meiosis
(d) Meiosis, karyogamy and plasmogamy
Ans: (c) The sexual cycle involves the following three steps:
1. Fusion of protoplasms between two motile or non-motile gametes called
plasmogamy.
• Plasmogamy is fusion of two haploid cells without nuclear fusion.
2. Fusion of two nuclei is called karyogamy.
3. Meiosis in zygote resulting in haploid spores.
Q11. Viruses are non-cellular organisms but replicate themselves once they infect the host cell. To which of the following kingdom do viruses belong to?
(a) Monera (b) Protista (c) Fungi (d) None of these
Ans: (d) Viruses did not find a place in classification since they are not truly ‘living’ if we understand living as those organisms that have a cell structure. Viruses are neither prokaryotes nor eukaryotes. They are inert outside their specific host cell and cannot multiply of their own because they lack cellular machinery to use its genetic material. Viruses can only multiply in host or living cell.
Q12. Members of Phycomycetes are found in
(1) Aquatic habitats
(ii) On decaying wood
(iii) Moist and damp places
(iv) As obligate parasites on plants Choose from the following options.
(a) None of the above (b) (i) and (iv)
(c) (ii) and (iii) (d) All of the above
Ans: (d) Members of Phycomycetes are found in aquatic habitats, on decaying wood, moist and damp places and as obligate parasites on plants.
Very Short Answer Type Questions
Q1. What is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement?
Ans: Cyanobacteria (BGA) are autotrophic microbes. Cyanobacteria are widely distributed in aquatic and terrestrial environments. Nostoc, Ariabaena and Oscillatoria are BGA that can fix atmospheric nitrogen. These organisms can fix atmospheric nitrogen in specialised cells called heterocysts, e.g., Nostoc and Anabaena. In paddy fields cyanobacteria serve as an important biofertiliser. BGA also add organic matter to the soil and increase its fertility.
Q2. Suppose you accidentally find an old preserved permanent slide without a label. In your effort to identify it, you place the slide under microscope and observe the following features:
a. Unicellular ‘
b. Well defined nucleus
c. Biflagellate—one flagellum lying longitudinally and the other transversely.
What would you identify it as? Can you iiamethe kingdom it belongs to?
Ans: Dinoflagellates are unicellular eukaryotes. Most of them have two flagella; one lies longitudinally and the other transversely in a furrow between the wall plates. Dinoflagellates belongs to kingdom protista.
Q3. How is the five-kingdom classification advantageous over the two kingdom classification?
Ans: Two Kingdom system of classification with Plantae and Animalia kingdoms.
1. Two kingdom classification did not distinguish between the prokaryotes and eukaryotes. E.g.: It brought together the prokaryotic bacteria and blue green algae with other groups (like plant, fungi and animals) which were eukaryotic.
2. Two kingdom classification did not distinguish between the unicellular and multicellular organisms. E.g:: Chlamydomonas (unicellular) and Spirogyra (multicellular) were placed together under algae.
3. This system did not distinguish between autotrophic/photosynthetic (green algae and plants) and the heterotrophic/non-photosynthetic organisms (fungi).
Five Kingdom Classification:
1. Fungi were placed in a separate kingdom—kingdom fungi.
2. It has put together organisms which were placed in different kingdoms in earlier classifications.
Kingdom Protista brought together Chlamydomonas, Chlorella (earlier placed in algae within plants and both having cell walls) with Amoeba and Paramoecium (earlier plaeed in the animal kingdom and both lacking cell walls).
3. Animal and plant kingdoms become more homogenous than they are in the two kingdom classification. So, it is the advantageous over the two kingdom classification.
Q4. Polluted water bodies have usually veryhigh abundance of plants like Nostoc and Oscillitoria. Give reasons.
Ans: Polluted water bodies (Ponds, ditches and rivers etc.) have usually nutrient contents (such as nitrate, phosphates) domestic sewage primarily contains biodegradable organic matter. Presence of large amount of nutrients in waters also causes excessive growth of Planktonic (free floating algae) called an algal bloom, which imparts a distinct colour to water bodies.
Algal bloom causes deterioration of the water quality and fish mortality. Some bloom forming algae mainly Nostoc and Oscillitoria are extremely toxic to human beings and animals.
Q5. Are chemosynthetic bacteria—autotrophic or heterotrophic?
Ans: Chemosynthetic bacteria oxidise various inorganic substances such as nitrates, nitrites and ammonia and use the released energy for their ATP production. So chemosynthetic bacteria are autotrophic in nature.
Q6. The common name of pea is simpler than its botanical (scientific) name Pisum sativum. Why then is the simpler common name not used instead of the complex scientific/botanical name in biology?
Ans: As we know that pea (vernacular name or local name) is simpler than its botanical (scientific) name Pisum sativum. These local names would vary from place to place, even within a country. Probably one would recognise the confusion that would be created if we did not find ways and means to talk to each other, to refer to organisms we are talking about.
Hence, there is a need to standardise the naming of living organisms such that a particular organism is known by the same name all over the world.
Q7. A virus is considered as a living organism and an obligate parasite when inside a host cell. But virus is not classified along with bacteria or fungi. What are the characters of virus that are similar to non-living objects?
Ans: Virus are living organisms inside a host cell. But virus is not classified along with bacteria or fungi because they having an inert crystalline structure outside the living cell. They are inert outside their specific host cell and cannot multiply of their own because they lack cellular machinery to use its genetic material.
Q8. In the five kingdom system of Whittaker, how many kingdoms are eukaryotes?
Ans: In the five kingdom system of Whittaker, four kingdoms (Protista, fungi,
plantae and animalia) belong to eukaryotes.
Short Answer Type Questions
Q1. Diatoms are also called as ‘pearls of ocean’, why? What is diatomaceous earth?
Ans: The diatoms are the unique organisms, because of their distinctive cell walls. The walls are embedded with silica and thus the walls are indestructible. It show sculpturing and ornamentation that why Diatoms are also called as ‘Pearls of Ocean’.
Diatoms have left behind large amount of cell wall deposits in their habitat; this accumulation over billions of years is referred to as ‘diatomaceous earth’. Being gritty this soil is used in polishing, filtration of oils and syrups. Diatoms are the chief ‘producers’ in the oceans.
Q2. There is a myth that immediately after heavy rains in forest, mushrooms appear in large number and make a very large ring or circle, which may be several metres in diameter. These are called as ‘Fairy rings’. Can you explain this myth of fairy rings in biological terms?
Ans: After heavy rains in forest, moisture and nutrients pass down in soil and activates the growth of mushroom mycelium. The basidiocarps of Agaricus (mushroom) arise from the mycelium present in the soil. They appear in a circle like a ring. As these basidiocarps resemble buttons and grow in rings, they are known as fairy rings.
Q3. Neurospora—an ascomycetes fungus has been used as a biological tool to understand the mechanism of plant genetics much in the same way as Drosophila has been used to study animal genetics. What makes Neurospora so important as a genetic tool?
Ans: Neurospora is used as a genetic tool because it is easy to grow and has a haploid life cycle that makes genetic analysis simple since recessive traits will show up in the offspring. Beadle and Tatum exposed Neurospora crassa to X-rays, causing mutations. This led them to propose the “one gene, one en2yme” hypothesis that specific genes code for specific proteins.
Q4. Cyanobacteria and heterotrophic bacteria have been clubbed together in Eubacteria of kingdom Monera as per the “Five Kingdom Classification” even though the two are vastly different from each other. Is this grouping of the two types of taxa in the same kingdom justified? If so, why?
Ans: Cyanobacteria and heterotrophic bacteria have been clubbed together in Eubacteria of Kingdom Monera as per the “Five Kingdom Classification” because they do not have nuclear envelope and membrane bound organelles. Their genetic material is naked. They have 70S type of ribosomes. So, cyanobacteria and heterotrophic bacteria are prokaryotes and belong, to Kingdom Monera.
Q5. At a stage of their cycle, ascomycetes fungi produce the fruiting bodies like apothecium, perithecium or cleistothecium. How are these three types of fruiting bodies different from each other?
Ans: An apothecium is a wide, open, saucer-shaped or cup-shaped fruit body. It is sessile and fleshy. A cleistothecium is a globose, completely closed fruit body with no special opening to the outside. Perithecium are flask shaped structures opening by a pore or ostiole (short papilla opening by a circular pore).
Q6. What observable features in Trypanosoma would make you classify it under Kingdom Protista?
Ans: Trypanosoma is classified under the Kingdom Protista because it is unicellular eukaryotes. It has well defined nucleus with nuclear envelope, membrane bound organelles, 80S ribosomes and flagella with 9 + 2 organisation.
Q7. Fungi are cosmopolitan, write the role of fungi in your daily life.
Ans: Dough which is used for making bread, is fermented by fungi Saccharomyces cerevisiae (Baker’s yeast).
Roquefort cheese are ripened by growing a specific fungi on them, which gives them a particular flavour.
Microbes mainly yeasts used for the production of beverages like wine, beer, whisky, brandy or rum. For this purpose the yeast (Saccharomyces cerevisiae) used for fermenting malted cereals and juices to produce ethanol and commonly called Brewer’s yeast
Antibiotics produced by Fungi:
1.
Penicillin
Penicillium notatum and Penicillium chrysogenum
2.
Griseofulvin
Penicillium griseofulvum
3.
Cephalosporin
Cephalosporium acremonium
4.
Gentomycin
Micromonospora purpurea
  • Cyclosporin A is produced by Trichoderma polysporum (Fungus). Cyclosporin A is used as an immunosuppressive agent in organ transplant patients.
  • Statins produced by Monascus purpureus(Yeast). Statins used as blood- cholesterol lowering agent.
  • Mushrooms, morels (Morchella) and truffles are edible fungi.
  • Fungi causes several diseases in plants and animals including human beings.
Long Answer Type Questions
Q1. Algae are known to reproduce asexually by variety of spores under different environmental conditions. Name these spores and the conditions under which they are produced.
Ans: Asexual reproduction is by the production of different types of spores, the most common being the zoospores. They are flagellated (motile) and on germination gives rise to new plants.
Types of asexual reproduction:
1. Zoospores: Motile and formed in favourable condition.
2. Aplanospores: Thin walled, non-motile and formed in unfavourable condition.
3. Hypnospore: Thick walled, non-motile and formed in unfavourable condition.
4. Akinete: Under unfavourable condition, entire cell becomes thick.
5. Palmella stage: In condition of drought, protoplast is surrounded by gelatinous covering.
Q2. Apart from chlorophyll, algae have several other pigments in their chloroplast. What pigments are found in blue-green, red and brown algae that are responsible for their characteristic colours?
Ans: Apart from chlorophyll, algae have several other pigments in their chloroplast like carotenoids, xanthophylis (fucoxanthin) and r-phycoerythrin. In blue- green algae phycocyanin and r-phycoerythrin pigments are present beside chlorophyll a.
• Brown algae possess chlorophyll a, c, carotenoids and xanthophylls. They vary in colour from olive green to various shades of brown depending upon the amount of the xanthophyll pigment, fucoxanthin present in them.
• Red algae possess chlorophyll a, d and phycoerythrin in their body. The members of rhodophyceae are commonly called red algae because of the predominance of the red pigment, r-phycoerythrin in their body.
Q3. Make a list of algae and fungi that have commercial value as source of food,
chemicals, medicines and fodder.
Ans:
A. Economic importance of Algae:
1. Many species of Porphyra, Laminaria and Sargassum are among the 70 species of marine, algae used as food. Chlorella and Spirullina are unicellular algae, rich in proteins and are used as food supplements even by space travellers.
2. Certain marine brown and red algae produce large amounts of hydrocolloids (water holding substances) or phycocolloids, e.g.: algin (brown algae) and carrageen (red algae) are used commercially. Agar, one of the commercial products obtained from Gelidium and Gracilaria are used to grow microbes and in preparations of ice-creams and jellies.
3. Bromine is obtained from red algae Polysiphonia. Macrocystis is the source of Potash. Laminaria and Fucus are the source of Iodine.
B. Economic importance of Fungi:
1. Mushrooms, morels (Morchella) and truffles are edible fungi.
2. Microbes mainly yeasts used for the production of beverages like wine, beer, whisky, brandy or rum. For this purpose the yeast {Saccharomyces cerevisiae) used for fermenting malted cereals and juices to produce ethanol and commonly called Brewer’s yeast.
• Cyclosporin A is produced by Trichoderma polysporum (Fungus). Cyclosporin A is used as an immunosuppressive agent in organ transplant patients.
• Statins produced by Monascus purpureus (Yeast). Statins used as the blood-cholesterol lowering agent.
Penicillin
Penicillium notatum and Penicillium chrysogenum
Griseofulvin
Penicillium griseofulvum
Cephalosporin
Cephalosporium acremonium
Gentomycin
Micromonospora purpurea
Q4. ‘Peat’ is an important source of domestic fuel in several countries. How is ‘peat’ formed in nature?
Ans: Species of Sphagnum, a moss, provide peat that have long been used as fuel and because of their capacity to hold water as packing material for trans-shipment of living material. Peat forms when plant material decaying fully by acidic and anaerobic conditions. Peat is soft and easily compressed. Under pressure, water in the peat is forced out. Upon drying, peat can be used as fuel.
Q5. Biological classification is a dynamic and ever evolving phenomenon which keeps changing with our understanding of life forms. Justify the statement taking any two examples.
Ans: Kingdom Protista brought together Chlamydomonas, Chlorella (earlier placed in algae within plants and both having cell walls) with Amoeba and Paramoecium (earlier placed in the animal kingdom and both lacking cell walls). Five kingdom classification has put together organism (like Chlamydomonas and Amoeba) which were placed in different kingdoms in earlier classifications. This change happened because the criteria for classification changed. 

LIVING WORLD


Multiple Choice Questions
Single Correct Answer Type
Q1. As we go from species to kingdom in a taxonomic hierarchy, the number of common characteristics
(a) Will decrease (b) Will increase
(c) Remain same (d) May increase or decrease
Ans: (a) As we go higher from species to kingdom, the number of common characteristics goes on decreasing. Lower the taxa, more are the characteristics that the members within the taxon share. Higher the category, greater is the difficulty of determining the relationship to other taxa at the same level.
Q2. Which of the following ‘suffixes’ used for units of classification in plants indicates a taxonomic category of family’?
(a) —Ales (b) —Onae (c) —Aceae (d) —Ae
Ans: (c)
(a) —Ales —» Order (plant) .
(b) —Onae —» Class (plant)
(c) —Aceae —> Family (plant)
(d) —Ae —> Phylum (plant)
Q3. The term ‘systematics’ refers to
(a) Identification and classification of plants and animals •
(b) Nomenclature and identification of plants and animals
(c) Diversity of kinds of organisms and their relationship
(d) Study of habitats of organisms and their classification
Ans: (c) Human beings were, since long, not only interested in knowing more about different kinds of organisms and their diversities, but also the relationships among them. This branch of study was referred to as systematics. Systematics takes into account evolutionary relationships between organisms.
Q4. Genus represents .
(a) An individual plant or animal
(b) A collection of plants or animals
(c) Group of closely related species of plants or animals
(d) None of these
Ans: (c) Genus comprises a group of related species which has more characters in common in comparison to species of other genera.
Q5. The taxonomic unit ‘Phylum’ in the classification of animals is equivalent to which hierarchical level in classification of plants?
(a) Class (b) Order (c) Division (d) Family
Ans: (c) Classes comprising animals like fishes, amphibians, reptiles, birds along with mammals constitute the next higher category called Phylum. All these classes are included in the phylum chordata. In case of plants, classes with a few similar characters are assigned to a higher category called Division.
Q6. Botanical gardens and zoological parks have
(a) Collection of endemic living species only
(b) Collection of exotic living species only
(c) Collection of endemic and exotic living species
(d) Collection of only local plants and animals
Ans: (c) Botanical gardens and zoological parks have collection of endemic and exotic living species.
Q7. Taxonomic key is one of the taxonomic tools in the identification and classification of plants and animals. It is used in the preparation of 
(a) Monographs (b) Flora
(c) Both (a) and (b) (d) None of these
Ans: (c) .
• Flora contains the actual account of habitat and distribution of plants
of a given area. These provide the index to the plant species found in a particular area. . .
• Manuals are useful in providing information for identification of names of species found in an area. Monographs contain information on any one taxon, i.e. any one genus or family at a particular time. They also help in correct identification.
Q8. All living organisms are linked to one another because
(a) They have common genetic material of the same type
(b) They share common genetic material but to varying degrees
(c) All have common cellular organization
(d) All of the above
Ans: (b) All living organisms—present, past and future are linked to one another by the sharing of the common genetic material, but to varying degrees.
Q9. Which of the following is a defining characteristic of living organisms?
(a) Growth (b) Ability to make sound
(d) Reproduction (d) Response to external stimuli 
Ans. (d) Response to external stimuli is a defining characteristic of living organisms.
Q10. Match the following and choose the correct option.
A.
Family
(0
tuberosum
B.
Kingdom
(ii)
Polymoniales
C.
Order
(iii)
Solarium
D.
Species
(iv)
Plantae
E.
Genus
(v)
Solanaceae
Options:
(a) D—(i), C—(ii), E—(iii), B—(iv), A-(v)
(b) E—(i), D—(ii), B—(iii), A—(iv), C-
(c) D-C), E—(ii), B—(iii), A—(iv), C-(v)
(d) E—(i), €—(ii), B—-(iii), A-(iv), D-(v)
Ans: (a)
D.
Species
(i)
tuberosum
C.
Order
(ii)
Polymoniales
E.
Genus
(iii)
Solatium
B.
Kingdom
(iv)
Plantae
A.
Family
(v)
Solanaceae
Very Short Answer Type Questions
Q1. Linnaeus is considered as Father of Taxonomy. Name two other botanists known for their contribution to the field of plant taxonomy.
Ans: Natural system of classification for flowering plants was given by George Bentham and Joseph Dalton Hooker, in three volume of Genera Plantarum.
Q2. What does ICZN stand for? 
Ans: ICZN stand for International Code of Zoological Nomenclature.
Q3. Couplet in taxonomic key means .
Ans: The keys are based on the contrasting characters generally in a pair called couplet. It represents the choice made between two opposite options. This results in acceptance of only one and rejection of the other.
Q4. What is a Monograph?
Ans: Monographs contain information on any one taxon, i.e. any one genus or family at a particular time.
Q5. Amoeba multiplies by mitotic cell division. Is this phenomena growth or reproduction? Explain.
Ans: In single-celled organisms, we are not very clear about the usage of these two terms—growth and reproduction.
Q6. Define metabolism.
Ans: The sum total of all the chemical reactions occurring in our body is metabolism.
Q7. Which is the largest botanical garden in the world? Name a few well known botanical gardens in India.
Ans: Largest famous botanical garden of world is Royal Botanical Garden, Kew (London), England. Largest botanical garden of India is Indian Botanical Garden, Sibpur, Howrah, Kolkata, West Bengal. National Botanical Research Institute is situated at Lucknow (India).
Short Answer Type Questions
Q1. A ball of snow when rolled over snow increases in mass, volume and size. Is this comparable to growth as seen in living organisms? Why?
Ans: No, this is not comparable to growth as seen in living organisms. Non-living objects like snow ball also grow if we take increase in body mass as a criterion for growth. However, this kind of growth exhibited by non-living objects is by accumulation of material on the surface (accretion). In living organisms, growth is from inside. ‘
Q2. In a given habitat we have 20 plant species and 20 animal species. Should we call this as ‘diversity’ or ‘biodiversity’? Justify your answer. –
Ans: In a given habitat we have 20 plant species and 20 animal species. We can call this as ‘biodiversity’. Each different kind of plant, animal or organism that we see, represents a species. This refers to biodiversity or the number and types of organisms present on earth.
Q3. International Code of Botanical nomenclature (ICBN) has provided a code for classification of plants. Give hierarchy of units of classification botanists follow while classifying plants and mention different ‘Suffixes’ used for the units.
Ans:
Taxon
Suffixes
Kingdom
T
No definite suffix
Division
T
phyta/spermae
Class
T
nae/opsida
Order
r
ales
Family
T
aceae
Genus
T
No definite suffix
Species
No definite suffix
 
Q8. Brinjal and potato belong to the same genus Solarium, but to two different species. What defines them as separate species?
Ans. “Species is a group of potentially interbreeding groups that are reproductively isolated from other such groups”. Brinjal and potato belong to the same genus Solarium, but to two different species as they are reproductively isolated.
Q9. Properties of cell organelles are not always found in the molecular constituents of cell organelles. Justify.
Ans. All living phenomena are due to underlying interactions. Properties of tissues are not present in the constituent cells. Similarly, properties of cellular organelles are not present in the molecular constituents of the organelle but arise as a result of interactions among the molecular components comprising the organelle. These interactions result in emergent properties at a higher level of organization. This phenomenon is true in the hierarchy of organisational complexity at all levels.
10. The number and kinds of organism is not constant. How do you explain this statement?
Ans. The number and kinds of organisms are variable according to the seasonal changes like, population of certain insects increases during rainy season. The IUCN Red List (2004) documents the extinction of 784 species (including 338 vertebrates, 359 invertebrates and 87 plants) in the last 500 years.
Long Answer Type Questions
Q1 .What is meant by living? Give any four defining features of life forms.
Ans: Growth, reproduction, cellular organisation, ability to sense environment and mount a suitable response, metabolism, ability to self-replicate, self-organise, interact and emergence are unique features of living organisms.
Some other characteristics of living organisms are life-span, movements, adaptations, variations and homeostasis, etc. Living organisms are self- replicating, evolving and self-regulating interactive systems capable of responding to external stimuli.
1. Metabolism: There are thousands of metabolic reactions occurring simultaneously inside all living organisms, be they are unicellular or
, multicellular. The sum total of all the chemical reactions occurring in our body is metabolism. All plants, animals, fungi and microbes exhibit metabolism. No non-living objects exhibit metabolism. Metabolic reactions can be demonstrated outside the body in cell free system. An isolated metabolic reaction(s) outside the body of an organism performed in a test tube is neither living nor non-living.
Hence, while metabolism is a defining feature of all living organisms without exception, isolated metabolic reactions in vitro are not living things but surely living reactions.
2. Cellular Organisation: All living organisms are composed of cells and products of cells. Hence, cellular organization of the body is the defining feature of life forms.
3. Consciousness: Perhaps, the most obvious and technically complicated feature of all living organisms is this ability to sense their surroundings or environment and respond to these environmental stimuli which could be physical, chemical or biological. All organisms, from the prokaryotes to the most complex eukaryotes can sense and respond to environmental cues.
All organisms handle chemicals entering their bodies. All organisms ‘ therefore are aware of surroundings. Plants respond to external factors like light, water, temperature, other organisms, pollutants, etc. Photoperiod affects reproduction in seasonal breeders, both plants and animals. Consciousness, therefore, becomes the defining property of living organisms.
4. Interactions: All living phenomena are due to underlying interactions. Properties of tissues are not present in the constituent cells. Similarly, properties of cellular organelles- are not present in the molecular constituents of the organelle but arise as a result of interactions among the molecular components comprising the organelle. These interactions result in emergent properties at a higher level of organization. This phenomenon is true in the hierarchy of organisational complexity at all levels.
Q2. A scientist has come across a plant which he feels is a new species. How will he go about its identification, classification andnomenclature? .
Ans: Obviously, nomenclature or naming is only possible when the organism is described correctly. This is identification. Reference collections of plant specimens are collected into herbarium and identified. Most plant parts are dried, pressed, mounted on herbarium sheets and stored.
 . Classification is the process by which anything is grouped into convenient categories based on some easily observable characters. The earliest systems of classification used only gross superficial morphological characters such as habit, colour, number and shape of leaves, etc. They were based mainly on vegetative characters or on the androecium structure (system given by Linnaeus). Such systems were artificial.
• Natural classification systems is based on natural affinities among the organisms and consider, not only the external features, but also internal features, like ultra-structure, anatomy, embryology and phytochemistry. Natural system of classification for flowering plants was given by George Bentham and Joseph Dalton Hooker, in three volume of Genera Plantarum.
• At present phylogenetic classification systems basad on evolutionary relationships between the various organisms are acceptable. This assumes that organisms belonging to the same taxa have a common ancestor. First phylogenetic system was proposed by Engler and Prantlin monograph ‘Die NaturlichenPflanzenFamilien’.
• In order to facilitate the study, number of scientists have established procedures to assign a scientific name to each known organism. This is acceptable to biologists all over the world. The system of providing scientific names is called Binomial nomenclature.
• Each name has two components—the Generic name and the specificepithet. This system of providing a name with two components is called Binomial nomenclature. This naming system given by Carolus Linnaeus is being practiced by biological all over the world. This naming using a two word format was found convenient.
Q3. Brassica compestris Linn
a. Give the common name of the plant.
b. What do the first two parts of the name denote?
c. Why are they written in italics?
d. What is the meaning of Linn written at the end of the name? 
Ans: a. Mustard
b. The first word in a biological name represents the genus while the second component denotes the specific epithet.
c. Both word in a biological name, when handwritten, are separately underlined, or printed in italics to indicate their Latin origin.
d. Name of the author appears after the specific epithet, i.e. at the end of
the biological name and is written in an abbreviated form, e.g., Brassica compestris Linn. It indicates that this species was first described by Linnaeus.
Q4. What are taxonomical aids? Give the importance of herbaria and museums. How are Botanical gardens and Zoological parks useful in conserving biodiversity?
Ans: Taxonomic studies of various species of plants, animals and other organisms are useful in agriculture, forestry, industry and in general in knowing our bio-resources and their diversity. ,
• Herbarium is a store house of collected plant specimens that are dried, pressed and preserved on sheets. Further, these sheets are arranged according to a universally accepted system of classification.
• The herbarium sheets carry a label providing information about date and place of collection, English, local and botanical names, family, collector’s name, etc. Herbaria also serve as quick referral systems in taxonomical studies.
• Biological museums are generally set up in educational institutes such as schools and colleges. Museums have collections of preserved plant and animal specimens for study and reference. Specimens are preserved in the containers or jars in preservative solutions. Plant and animal specimens may also be preserved as dry specimens.
• Insects are preserved in insect boxes after collecting, killing and pinning. Larger animals like birds and mammals are usually stuffed and preserved. Museums often have collections of skeletons of animals too.
• Biodiversity conservation may be in-situ as well as ex -situ. However when there are situations where an animal and plant is endangered or threatened and need urgent measure to save it from extinction, ex-situ conservation is the desirable approach.
• In ex-situ conservation threatened animals and plants are taken out from natural habitat and placed in special place where they can be protected and given special care. Zoological park, botanical garden and wildlife safari park serve these purpose.
Q5. Define a taxon. What is meant by taxonomic hierarchy? Give a flow diagram from the lowest to highest category for a plant and an animal. What happens to the number of individuals and number of shared characters as we go up the taxonomical hierarchy? 
Ans: Taxon is a taxonomic group of plants and animals with similar traits of any ranking. These taxonomic groups/categories are distinct biological entities and not merely morphological aggregates.
Classification is not a single step process but involves hierarchy of steps in which each step represents a rank or category. Since the category is a part of overall taxonomic arrangement, it is-called the taxonomic category and all categories together constitute the taxonomic hierarchy.
As we go higher from species to kingdom, the number of common characteristics goes on decreasing. Lower the taxa, more are the characteristics that the members within the taxon share. Higher the category, greater is the difficulty of determining the relationship to other taxa at the same level. As we go higher from species to kingdom, the number of individuals goes on increasing.
Q6. A student of taxonomy was puzzled when told by his professor to look for a key to identify a plant. He went to his friend to clarify what ‘Key’ the professor was referring to? What would the friend explain to him?
Ans: In reference of this question, ‘Key’ Stands for taxonomic keys. Key is the taxonomical aid used for identification of plants and animals based on the similarities and dissimilarities. The keys are based on the contrasting characters generally in a pair called couplet. It represents the choice made between two opposite options. This results in acceptance of only one and rejection of the other. –
Each statement in the key is called a lead. Separate taxonomic keys are required for each taxonomic category such as family, genus and species for identification purposes. Keys are generally analytical in nature.
Q7. Metabolism is a defining feature of all living organisms without exception. Isolated metabolic reactions in vitro are not living things but surely living reactions. Comment.
Ans: All-living organisms are made of chemicals.
• There are thousands of metabolic reactions occurring simultaneously inside all living organisms, be they are unicellular or multicellular. The sum total of all the chemical reactions occurring in our body is metabolism. All plants, animals, fungi and microbes exhibit metabolism.
• No non-living objects exhibit metabolism. Metabolic reactions can be demonstrated outside the body in cell free system. An isolated metabolic reaction(s) outside the body of an organism, performed in a test tube is neither living nor non-living. ‘
Hence, while metabolism is a defining feature of all living organisms without exception, isolated metabolic reactions in vitro are not living things but surely living reactions.
Q8. Do you consider a person in coma-living or dead?
Ans: Human being is the only organism who is aware of himself, i.e. has self-consciousness. We sense our environment through our sense organs (like ear, nose, eye, etc.). When it comes to human beings, it is all the more difficult to define the living state.
We observe patients lying in coma in hospitals virtually supported by machines which replace heart and lungs. The patient is otherwise brain- dead. The patient has no self-consciousness. So on this basis the person is considered as dead, but there are thousands of metabolic reactions occurring in the body, hence on the basis of metabolism the person is considered as living. So we can say that the person that lying in coma is neither living nor dead.
Q9. What is the similarity and dissimilarity between “whole moong daal” and “broken moong daal” in terms of respiration and growth? Based on these parameters classify them into living or nonliving?
Ans: Whole moong daal has intact embryo which respire at slow rate during dormancy phase. When whole moong daal absorb water it resumes growth and germinate to form a new plant.
Broken moong daal does not have intact embryo, so it cannot respire and do not germinate/grow. As whole moong daal can grow hence it is living while broken moong daal cannot grow hence non-living.
Q10. Some of the properties of tissues are not the constituents of its cells. Give three examples to support the statement.
Ans: Bone is a specialised connective tissue which is made up of osteocytes (bone cells). Bones provide mechanical support which is not provided by osteocytes.
• Dry surface of skin is a compound epithelium tissue that is made up of epithelial cells. Epithelial tissue protect skin from chemical and mechanical stresses while this property is not found in epithelial cells.
• Blood is a specialised connective tissue which is made up of RBCs, WBCs and Platelets. Blood help in the transport of nutrients inside the body while blood cells do not play a role in transport of nutrients.