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Tuesday, 21 April 2015

FSc Notes Biology Part 1 Chapter 11 Bioenergetics

         FSc Notes Biology Part 1 Chapter 11 Bioenergetics

Q 1. What is thylakoid?
Ans. In photosynthetic organisms, chloroplasts have vesicles a wall of which bears photosynthetic pigments, called thylakoid. They vary in form and arrangement in different groups of organisms.

Q 2. What is the function of stomata?
Ans. Stomata are pores present in the epidermis of plants in large numbers, particularly in leaves, through which gaseous exchange takes place.

Q 3. Define bioenergetics.
Ans. The study of energy transfer in living beings is called bioenergetics.

Q 4. Give approximate estimate of chloroplasts in a green leaf.
Ans. The number of chloroplasts is about half a million per square millimeter of the leaf surface.

Q 5. What does the absorption spectrum of a pigment mean?
Ans. A graph showing the absorption of light of different wavelength by a pigment is called its absorption spectrum.

Q 6. How does light affect opening and closing of stomata?
Ans. The stomata open in light and close in darkness.

Q 7. Where does Krebs cycle take place in the cell?
Ans. The Krebs cycle takes place in the mitochondria of the cell.

Q 8. What is the net production of ATP during glycolysis?
Ans. The net production of ATP during glycolysis is two molecules of ATP.

Q 9. What is FAD abbreviation for?
Ans. Fad is abbreviation for flavin adenine dinucleotide.

Q 10. Name two solvents of chlorophyll?
Ans. The solvents of chlorophyll are carbon tetrachloride and alcohol.

Q 11. Write down the first step in Krebs cycle?
Ans.  The first step in the Krebs cycle is the union of acetyl CoA with oxaloacetate to form citrate.

Q 12. Give definition of glycolysis.
Ans. Glycolysis is the conversion of glucose by means of enzymes and co-enzymes till the formation of pyruvic acid.

Q 13. What does a photo system of photosynthesis cell consist of?
Ans. A photo system consists of a light gathering antenna complex and a reaction center.

Q 14. How much of the total photosynthesis take place in water and on land?
Ans. Of the total photo synthesis 90 % takes place in water and 10 % on land.

Q 15. What is the source of energy used on earth?
Ans.  Almost all the energy used on earth comes directly from the sun.

Q 16. Write down the summarized equation for photosynthesis.
Ans.                                     Light
         6CO2  +  12H2O -------------->   C6H12O6  +  6O2  +  6H2O
Q 17. What is the source of oxygen released during photosynthesis in plants?
Ans. The source of oxygen released during photosynthesis in plants is the water.

Q 18. Write down molecular formula of chlorophyll's 'a' and 'b'.
Ans.  Chlorophyll 'a' C55H72O5N4Mg
          Chlorophyll 'b'C55H70O6N4Mg

Q 19. What are the end products of light reactions?
Ans. These are ATP and NADPH.

Q 20. What are the different kinds of chlorophyll and where are these found?
Ans. Chlorophyll a,b,c and d are found in eukaryotic photosynthetic plants and algae while the other found in photosynthetic bacteria are known as bacteria chlorophylls.

Q 21. What is the approximate number of chloroplasts in each mesophyll cell of the leaf?
Ans. It is about 20 to 1000 per mesophyll cell.

Q 22. Which wavelength of the light spectrum are least absorbed by the chlorophyll?
Ans. Green and yellow wavelength are least absorbed by the chlorophylls.

Q 23. What are the colors of chlorophylls 'a' and 'b'?
Ans. The colors of chlorophyll 'a' is blue-green while that of chlorophyll 'b' is yellow-green.

Q 24. What is the role of accessory pigments in light absorption?
Ans. The accessory pigments absorb light and transfer the energy to chlorophyll "a" which then initiates the light reactions.

Q 25. Who obtained first action spectrum and when?
Ans. A German biologist T.W. Engelmam obtained first action spectrum in 1883 using spirogyra.

Q 26. What is Z.scheme in photosynthesis?
Ans. The path of electrons through the photo systems during non-cyclic photo-phosphorylation is known as Z-scheme from its shape.

Q 27. What is chemiosmosis in photosynthesis?
Ans. The synthesis of ATP by obtaining the energy through electrons of the electron transport chain is called chemiosmosis.

Q 28. Who and when was awarded Nobel Prize for his work on dark reactions in photosynthesis?
Ans. Melvin Calvin was awarded Nobel Prize in 1961 for his work on dark reactions on photosynthesis.

Q 29. Name the chain of acids which are formed in a cycle, starting from the citrate, during the Krebs cycle of respiration.
Ans. The chain is from citrate to a-ketoglutorate to succinate to fumarate to malate and finally to oxaloacetate.

Q 30. Define grana.
Ans. In chloroplasts group of disc-shaped, flattened vesicles stacked like coins in a pile, vesicle membranes bearing photosynthetic pigments are called grana. They are most highly developed in chloroplasts of higher plants.

Q 31. Compare which medium, water or air is better for oxygen?
Ans.  Feature                  Water                           Air
         Oxygen contents      10 ml O2 / liter               200 ml O2 / liter
         Rate of diffusion       less                                More (8000 times water)
         Viscosity                  More (50 times)             Less
          Density                   More (8000 times)         Less
          Ventilation               Difficult                          Easy

Q 32. Compare different phases of breathing?
Ans.  Feature               Inspiration                          Expiration
         Other name           Inhalation                             Exhalation
         Basic Mechanism  Passive expansion of lungs    Passive contraction of lungs
         Definition              Taking in of air                     Removal of air from lungs outside body
         Diaphragm            Contracts, moves down       Relaxes, moves up, become more
                                      becomes less dome-like      dome-like 
         Rib Muscles          Contract                              Relax
         Rib cage             Moves upward and forward    Moves downward and inward
         Volume of thorax   Increases                              Decreases
         Pressure on lungs   Decreases                            Increases
         Air moves              Into lungs                             Out of lungs

Q 33. Write down the differences between photorespiration and Calvin cycle.
Ans.   Photorespiration                                     Calvin Cycle
           Oxygen is fixed                                       Carbon dioxide is fixed
          Carbon dioxide is produced                    Oxygen is produced
          Oxygenase is involved                             Carboxylase is involved
          It retards growth                                     It promotes growth

Q 34. Describe respiratory disorders briefly.
Ans.  Disease: Respiratory distress syndrome
Feature: Syndrome of premature infants with gestation period less than 7 months
Cause: Decreased surfactant production
Symptom: No gaseous exchange
Disease: Cancer
Feature: Malignant tumor of lung cancer
Cause: Smoking
Disease: Tuberculosis
Feature: Pulmonary tuberculosis, contagious
Cause: Mycobacterium tuberculosis, poor people, malnutrition, poor living conditions
Symptom: Cough, fever
Disease: Asthma
Feature: Allergic reaction of respiratory tract
Cause: Pollen, spores, humidity, pollution
Symptom: Severe paroxysm of difficult breathing followed by a period of complete relief with recurrent attacks
Disease: Emphysema
Feature: Breakdown of alveoli
Cause: Smoke
Symptom: Smoker's cough. decrease in absorptive area, breathlessness, increased airway resistance

Q 35. How much carbon dioxide is present in venous and arterial blood?
Ans. Arterial blood contains about 50 ml of carbon dioxide per 100 ml of blood while venous blood contains about 54 ml.

Q 36. How does air always remain in the lungs of human beings?
Ans. About 1.5 liter air always remain in the lungs of human beings.

Q 37. What are the products which are produced during photorespiration?
Ans. Glycolate, glycine, serine.

Q 38. How much a water medium is denser than air medium for exchange of respiratory gases?
Ans. Water medium is 8000 times denser than air medium for exchange of respiratory gases.

Q 39. Write difference between Aerobic and Anaerobic respiration.
Ans.  Aerobic Respiration                             Anaerobic Respiration
          Free O2 is required                             Reaction occurs in the absence of free O2
          Glucose is completely oxidized            Some intermediate components are formed due to
          into CO2 and H2O                             incomplete oxidation e.g., lactic acid and alcohol
          Relatively larger amount of energy        Small amount of energy is formed (2 ATP)
          (38 ATP) is released
          In addition to glycolysis, Krebs           Only glycolysis occurs
          cycle and ETC also occur

Q 40. List four features of lead which show that it is able to carry out photosynthesis effectively.
Ans. Feature                                          Significance
        Flatness of lamina                            Maximum light absorption
        Thickness of lamina                         Deep penetration of light and efficient, rapid interval diffusion
                                                              of gases (CO2, O2) throughout the leaf
        Supported on petiole and green       Exposure to sunlight and air
        Cuticle                                            Reduce loss of water by transpiration
        Mesophyll tissue; with chloroplasts,  The photosynthetic tissue
        more in palisade than in spongy:
        Palisade mesophyll                          Characteristic arrangement chloroplast can orient themselves
                                                               according to incident light. Also act as screen against intense
                                                               light. Main photosynthetic tissue
        Spongy mesophyll                           Loose arrangement of cells and air spaces absorption and rapid
                                                              diffusion of CO2 to mesophyll cells; photosynthetic tissue.

Q 41. How does light affect opening of stomata?
Ans. Guard cells are the only photosynthesizing cells of lower epidermis. So in the presence of light, photosynthesis starts and water is used. More water moves into guard cells form surroundings cells, they become turgid, and the inner thick walls bend outwards at the center, thus they produce an opening or pore. It would happen when osmotic potential of guard cells becomes less then that of surrounding epidermal cells. It means light is the driving force for opening of stomata.

Q 42. What causes the variation of osmotic potential in the guard cells?
Ans. Photosynthesis causes the variations of osmotic potential in the guard cells, by use and disuse of water. If photosynthesis is going on, water is being used causing an increase in osmotic potential and movement of water into guard cells. On the other hand when there is no photosynthesis, there will be no use of water so it accumulates in guard cells, thus decreasing osmotic potential and water may move out of the guard cells.

Q 43. Compare cyclic and non-cyclic phosphorylation.
Ans.  Non-Cyclic                                             Cyclic
         Electrons are not reused                           Electrons are reused
         It involves both PS I and II                       It involves only PS I
         It is long circuit                                         It is short circuit
         It is normal process                                  It occurs when ATP are less and NADPH more.
         It generates both ATP and NADPH          It generates only ATP
         Oxygen is released                                    Oxygen is not released

Q 44. Write down the differences between light and dark reaction.
Ans.  Light Reaction                                        Dark Reaction
         Occur in grana of chloroplast                  Occurs in matrix of chloroplast
         Light is required                                      Light is not required
         O2, ATP and NADPH2 are the               In Calvin cyclic, ATP and NADPH2
         end products                                          used to prepare carbohydrates

Q 45. Compare Haemoglobin with Myoglobin?
Ans. Hemoglobin                                            Myoglobin
        It is found in blood                                  It is found in muscles
        It transfers oxygen from lungs to blood     It transfers oxygen from hemoglobin to
        and then to tissues                                   aerobic respiring muscle cells
        It cannot store oxygen                              It can store oxygen
        It consists of four polypeptide chains        It consists of one polypeptide chain
        associated with an iron containing             associated with an iron containing ring
        ring structure                                            structure

Q 46. Define organismic and cellular respiration.
Ans. Organismic Respiration: It is also known as breathing or ventilation during which moist surface absorbs oxygen from the surrounding and carbon dioxide is removed. Organismic respiration in fact provides the basis of cellular respiration.
Cellular Respiration: The cellular respiration is directly involved in the production of energy, necessary for all living activities. Cellular respiration is the process by which cell utilizes oxygen, produce carbon dioxide, extracts and conserves the energy from food molecules in biologically useful form such as ATP. Cellular respiration in cells consists of three steps i.e., glycolysis, Krebs cycle and electron transport chain.The glycolysis takes place in the cytoplasm while other two steps are carried out in the mitochondria.

Q 47. Why are the carotenoids usually not obvious in the leaves? They can be seen in the leaves before leaf fall. Why?
Ans. The carotenoids are usually not obvious in the leaves as their yellowish color is covered by dark green color of chlorophyll. But just before leaf fall, the chlorophyll is destroyed and carotenoids can be seen.

Q 48. How is the formation of Vitamin A linked with eating of carrot?
Ans. Carrots contain carotenoids which are the precursors of vitamin A. This is why the formation of vitamin A is linked with eating of carrot.

Q 49. Explain the roles of the following in aerobic respiration: (a) NAD and FAD (b) Oxygen.
Ans.  NAD and FAD are the co-enzymes which help enzymes to carry out the reactions during aerobic respiration, whereas oxygen accepts the H atoms and make water in the last step of respiratory chain.

Q 50. Sum up how much energy (as ATP) is made available to cell from a single glucose molecule by the operation of glycolysis, the formation of acetyl CoA the citric acid cycle, and the electron transport chain.
Ans. For each glucose molecule that is completely broken down to CO2 and H2O molecules by the sequential actions of glycolysis, the Krebs cycle, and respiratory electron transport, 38 ATP molecules can be formed. 2 ATP molecules are obtained during glycolysis, 2 during Krebs cycle and 34 during respiratory chain.

Q 51. Trace the fate of hydrogen atoms removed from glucose during glycolysis when oxygen is present in muscle; compare this to the fate of hydrogen atoms removed from glucose when the amount of the available oxygen is insufficient to support aerobic respiration.
Ans. When oxygen is present in muscle cells, the hydrogen atoms removed from glucose during glycolysis are carried to respiratory chain but in the absence of oxygen they are used in alcoholic or lactic acid fermentation.

Q 52. What is the difference between an action spectrum and absorption spectrum?
Ans. Action Spectrum: Different wavelengths are not only differently absorbed by photosynthetic pigments but are also differently effective in photosynthesis. Plot showing relative effectiveness of different wavelengths of light in arriving photosynthesis is called action spectrum of photosynthesis.
Absorption Spectrum: A graph plotting absorption of light of different wavelength by a pigment is called absorption spectrum of the pigment. The peaks represent the light that is absorbed by the pigment, while the valleys represent the light that is reflected or transmitted.

Q 53. What is the net production of ATP during glycolysis?
Ans. 10 ATP are produced but 2 ATP are used in the beginning so there is a net gain of 8 ATP molecules.

Q 54. What is the main difference between photo-phosphorylation and oxidative phosphorylation?
Ans. Synthesis of ATP in the presence of light is called photo-phosphorylation while synthesis of ATP int the presence of oxygen is called oxidative phosphorylation.

Q 55. What is the location of ETC and chemiosmosis in photosynthesis and cellular respiration?
Ans. Thylakoid membranes in photosynthesis, and mitochondrial membranes in cellular respiration.

Q 56. How did the evolution of photosynthesis affect the metabolic pathway?
Ans. With the emergence of photosynthesis on earth, molecular oxygen began to accumulate slowly in the atmosphere. The presence of free oxygen made possible the evolution of respiration. Respiration releases great deal of energy, and some of this energy is used in the formation of adenosine triphosphate (ATP) molecules. ATP is a kind of chemical link between catabolism and anabolism.

Q 57. How does absorption spectrum of chlorophyll a differ from that of chlorophyll b?
Ans. The molecular formula fro chlorophyll a and b are:
               Chlorophyll A C55H72O5N4Mg
               Chlorophyll B C55H70O6N4Mg
Due to this slight difference in their structure, the two chlorophylls show slightly different absorption spectra and hence different colors. Some wave length not absorbed by chlorophyll a are very effectively absorbed by chlorophyll b and vice-versa. Such differences in structure of different pigments increase the range of wavelength of the light absorbed. Chlorophyll a is blue-green while chlorophyll b is yellow-green.

Q 58. Write difference between Chlorophyll a and Chlorophyll b.
Ans. Difference                        Chlorophyll A                    Chlorophyll B
        Molecular formula           C55H72O5N4Mg                   C55H70O6N4Mg
        Functional group              -CH3                                   -CHO
        Occurrence                       All photosynthetic                In association with
                                                  organism except                  chlorophyll a in all green
                                                  photosynthetic bacteria         plants and green algae
        Forms                               Differ slightly in their red       No such different forms
                                                 absorbing peaks e.g.,
                                                 670,680,690,700 nm
        Color                                Blue-green                             Yellow-green

Written By: Asad Hussain

Monday, 6 April 2015

FSc Notes Biology Part 1 Chapter 8 Fungi

           FSc Notes Biology Part 1 Chapter 8 Fungi

Q 1. What is hypha?
Ans. Hypha is a long, slender, branched and thread like filament of fungal body.

Q 2. What are fungi?
Ans. The eukaryotic organisms which have cell wall but cannot synthesize their food are called fungi.

Q 3. What is mycelium?
Ans. Mycelium is body of fungi which represent group of hyphae.

Q 4. What do you mean by Bio-remediation?
Ans.  Bioremediation means degrading or removal of environmental poisons or pollutants by the help of organisms.

Q 5. What is haustoria?
Ans. There are special hyphae produced in parasitic fungi. These hyphae penetrate into the host tissue and absorb food.

Q 6. What is the advantage of incomplete septa in septate hyphae?
Ans. Septa of many septate fungi have a pore through which cytoplasm flows from cell to cell, carrying materials to growing tips.

Q 7. Why yeasts are different from other fungi?
Ans. Yeasts are different from other fungi as they are unicellular.

Q 8. Name sexual and asexual spores of Ascomycota.
Ans. Sexual spores are called ascospores borne in asci while asexual spores are called conidia in Ascomycota.

Q 9. What are the main types of mycorrhiza?
Ans. (i) Endomycorrhizae: In which fungal hyphae penetrate the outer cell of the plant root, forming coils, swellings and minute branches, and also extend out into surrounding soil.
(ii) Ectomycorrhizae: In which the hyphae surround and extend between the cells but do not penetrate the cell wall of the roots. These are found in pines, firs etc.

Q 10. Why is green mould more likely to contaminate an orange kept in refrigerator than the bacteria?
Ans.  Fungi can tolerate temperature extremes 5-6 C below freezing and hence are more likely to contaminate an orange kept in a refrigerator than the bacteria.

Q 11. How fungi gets its nutrients?
Ans.  (i) Most fungi are decomposers i.e., obtain food from dead organisms. e.g., Yeast, Agaricus.
(ii) Some fungi are parasites i.e., obtain food from living host. e.g., rust and smut.
(iii) Some are predators e.g. Arthrobotrys.

Q 12. What do you mean by term karyogamy?
Ans. The fusion of nuclie in different mycelia is called karyogamy.

Q 13. What are yeasts?
Ans. Yeasts are unicellular microscopic fungi which are non-hyphal in structure.

Q 14. What is parasexuality?
Ans. The exchange of portion of chromosomes of two nuclei lying in the same hyphae.

Q 15. What are the benefits of mycorrhizae?
Ans.  The fungal hyphae of mycorrhizae increase the amount of soil contact and total surface area for absorption and help in direct absorption of minerals and nutrients from the soil.

Q 16. Name any four important fungal diseases of plants.
Ans.  (i) Rusts (ii) Smuts (iii) Powdery mildews (iv) Potato wilt

Q 17. Name any important fungal disease of humans.
Ans.  (i) Ringworm (ii) Aspergillosis (iii) Histoplasmosis (iv) Oral and vaginal thrush.

Q 18. Some enzymes of fungi are useful on one hand and harmful on other. Discuss.
Ans.  Some fungal enzymes are used in fermentation and brewing industry but digesting enzymes of some saprotrophic fungi spoil our food, plastic, paper and textile.

Q 19. What do you mean by Rust?
Ans.  It is a fungal disease of plants. As its color is brown like that of iron, so it is called as rust.

Q 20. What is the difference between dikaryotic and diploid?
Ans. Fungal cells having two nuclei of different genetic make up are called dikaryotic while having two sets of chromosomes in the nucleus of a cell or hypha is called diploid condition.

Q 21. Define obligate parasites.
Ans. Obligate parasites can grow only on their living host and cannot grow on available defined growth culture medium. For example many suit species.

Q 22. Differentiate between plasmogamy and karyogamy?
Ans. Fusion of cytoplasm is plasmogamy and fusion of nuclei is karyogamy.

Q 23. Define facultative parasite.
Ans. They can grow parasitically on their host as well as by themselves on artificial growth media.

Q 24. What are ascospores?
Ans. Most sac fungi have asci inside macroscopic fruiting bodies called ascospores, the visible morels.

Q 25. Write two differences between fungal and animal.
Ans. Fungi are different from animals as:
(i)They are non-motile.
(ii)They have absorptive mode of nutrition.

Q 26. What is ergotism?
Ans. Ergotism is caused by eating bread made from purple ergot-contaminated rye flour. The poisonous material in the ergot causes nervous spasm convulsion, even gangrene.

Q 27. What is the method of traping nematodes in arthrobotrys?
Ans. Some species of Arthrobotrys trap soil nematodes by forming constricting ring, their hyphae invading and digesting unlucky victim.

Q 28. How asexual reproduction takes place in fungi?
Ans. Asexual reproduction takes place by spores, conidia, fragmentation and budding.

Q 29. What is Rhodotorula?
Ans. Rhodotorula is a pink yeast which grows on shower curtains and other moist surfaces.

Q 30. Give a single characteristic that differentiates zygomycota from basidiomycota.
Ans. Zygospores are formed in zygomycota while basidiospores are the sexually reproducing spores in basidiomycota.

Q 31. What is the composition of fungal cell wall and how is this composition advantageous to fungi.
Ans. Cell wall of fungi is composed of chitin, which is more resistant to decay than are cellulose and lignin which make up plant cell wall.

Q 32. What do you mean by histoplasmosis?
Ans. It is serious infection of lungs caused by inhaling spores of a fungus, which is common in soil contaminated with bird's feces.

Q 33. Write two similarities of plants with fungi?
Ans. They resemble plants in some respects i.e.
(i) They have cell wall.
(ii) They lack centrioles and are non-motile.

Q 34. Write two dissimilarities of plants with fungi?
Ans. They differ plants as:
(i) Fungi are heterotrophs.
(ii) They lack cellulose in their cell walls and contain chitin.

Q 35. Differentiate between the members of Spore / Conidium.
Ans. Spore / Conidium: Spores are non-motile, small asexual structures produced inside the reproductive structures called sporangia, which are cut off from the hyphae by complete septa. Conidia are non-motile, asexual spores which are cut off at the end of modified hyphae called conidiophores, and not inside the
sporangia, usually in chains or clusters.

Q 36. Differentiate between the members of  Ascus / Basidium.
Ans. Ascus / Basidium: Basidiomycotes have sexual reproductive structure, the basidium, on which basidiospores are formed. Ascomycetes produce haploid sexual spores called ascospores inside their characteristic sac like structures called asci.

Q 37. Differentiate between the members of  Dikaryotic / diploid.
Ans.  Dikaryotic / diploid: A fungal hypha / cell having 2 nuclei of different genetic types is called dikaryotic hypha / cell. A cell or organism having full set of chromosomes e.g., 46 or 23 pairs in man, is called diploid.

Q 38. Differentiate between the members of Ascocarp / Ascus.
Ans.  Ascocarp / Ascus: Ascus is the characteristic sac like structure in which ascoposores are formed by meiosis while ascocarp is the macroscopic fruiting body in which asci are present.

Q 39. Differentiate between the members of  Obligate parasite / Facultative parasite.
Ans.  Obligate parasite / Facultative parasite: Obligate parasites can grow only on their living host and cannot be grown on available defined growth culture medium e.g., various mildews and most rust species. Facultative parasite can grow parasitically on their host as well as by themselves on artificial growth media

Q 40. Differentiate between the members of Endomycorrhizae / Ectomycorrhizae.
Ans.  Endomycorrhizae, in which the fungal penetrate the outer cell of the plant root, forming coils, swellings and minute branches, and also extend out into surrounding soil.
Ectomycorrhizae, in which the hyphae surround and extend between the cells but do not penetrate the cell walls of the roots. These are mostly formed with pines, firs etc. However, the mycelium extends far out into the soil in both kinds of mycorrhizae.

Q 41. Differentiate between the members of  Plasmogamy / Karyogamy.
Ans.  Plasmogamy / Karyogamy: The fusion of nuclei is called karyogamy while the fusion of cytoplasm is called plasmogamy.

Q 42. What are Hyphae? What is the advantage of having incomplete septa?
Ans. Hyphae: Mycelium consists of long slender, branched, tubular, thread like filaments called hyphae. Hyphae spread extensively over the surface of substratum. Their cell walls are composed of chitin, so their wall is highly resistant to decay. Hyphae may be septate or non-septate.
Advantage of having incomplete Septa: Cytoplasm flow from cell to cell, carrying the materials to growing tips and enabling the hyphae to grow rapidly when food and water are abundant and temperature is favorable.

Q 43. What is the composition of fungal cell wall and how it is this composition advantageous to fungi?
Ans. Fungal cell wall are composed of chitin, so their wall is more resistant to decay than cellulose and lignin which make up plant cell wall.

Q 44. To which phyla do the yeasts belong? How they differ from other fungi?
Ans. Yeasts are unicellular microscopic fungi, derived from all the three different groups of fungi but mostly Ascomycetes, and reproducing mostly asexually by budding. However, yeasts reproduce sexually by forming asci / ascospores or basidia / basidiospores. They ferment carbohydrate to ethanol and carbon dioxide. They are non-hyphal.

Q 45. Name sexual and asexual spores of ascomycetes.
Ans. Sexual spores are ascospores while asexual spores are conidia.

Q 46. What are mycorrhizae?
Ans. Mycorrhizae are mutualistic association between certain fungi and roots of vascular plants. The fungal hyphae dramatically increase the amount of soil contact and the total surface area for absorption and help in the direct absorption of phosphorus, zinc, copper and other nutrients from the soil into the roots. Such plants show better growth than those without this association. The plant, on the other hand, supplies organic carbon to fungal hyphae.

Q 47. By what means can individuals in imperfect fungi be classified?
Ans. Individuals in imperfect fungi can be classified on the basis of DNA sequence, though sexual structures may not be found.

Q 48. Give a single characteristic that differentiates Zygomycota from Basidiomycota.
Ans. In Zygomycota, non-septate, multinucleate hyphae are present while in Basidiomycota, septate dikaryotic hyphae are found.

Q 49. State two paralleled characteristic of ascomycete and Basidiomycetes.
Ans.(i) Their sexual spores are called ascopsores.
(ii) Nuclear fusion in the basidium is followed by meiosis.

Written By: Asad Hussain

Thursday, 2 April 2015

FSc Notes Biology Part 1 Chapter 10 Kingdom Animalia

   FSc Notes Biology Part 1 Chapter 10 Kingdom Animalia

Q 1. What is flame cell?
Ans. It is cup shaped cell with a bunch of cilia which work in its lumen. It is concerned with excretion. Flame cells are usually connected together by canals which ultimately open to the exterior of the animal.

Q 2. What are tetrapods?
Ans. All the animals having four limbs are called tetrapods. This super class is divided into following classes:
  1. Class Amphibia
  2. Class Aves
  3. Class Reptilia
  4. Class Mammalia

Q 3. Name the glass sponge of antarctica which is more than meter tall.
Ans. Its name Scolymastra joubini.

Q 4. What are nematocytes?
Ans. The nematocytes are the organs of offense and defense in the coelenterates.

Q 5. Quote examples of jawless fishes.
Ans. These are lampreys and hagfishes.

Q 6. Give example of a legless amphibian.
Ans. It is the Caecilian.

Q 7. Who proposed the word mammal?
Ans.  Linnaeus proposed the word mammal.

Q 8. How many aortic arches are formed in birds and mammals?
Ans. Only a single aortic arch is formed, right in birds  and left in mammals.

Q 9. Name a phylum which is exclusively marine.
Ans. It is phylum Echinodermata and Oxidaria.

Q 10. How do annelids respire?
Ans. The annelids respire through skin.

Q 11. State an example of a free living flat worm.
Ans.  Planaria is a free living flat worm.

Q 12. Name the intermediate host in the life cycle of tapeworm.
Ans. It is pig or cattle.

Q 13. What is the coelom of arthropods known as ?
Ans. The coelom of arthropods is known as the haemocoel.

Q 14. What is the cause of malaria?
Ans. The cause of malaria is a protozoan known as Plasmodium.

Q 15. What does the term calcareous mean?
Ans.  The term calcareous means made up of calcium carbonate.

Q 16. What are the molluscs with coiled shells known as?
Ans.  These are called gas tropods.

Q 17. Why has the name craniata been given to Vertebrate?
Ans. Since the vertebrates posses cranium, the vertebrate is also known as Craniata.

Q 18. State examples of bony fishes.
Ans. These are trout, perch plaice.

Q 19. Name two flight less birds.
Ans. These are ostrich and kiwi.

Q 20. What is the other name of external ear of mammals?
Ans. The external ear of mammals is called pinna.

Q 21. Name the early mammal like reptile which was found as fossil in Texas.
Ans. Its name is Varanope.

Q 22. What is hydrostatic skeleton?
Ans. Arrangement in animal or organ conferring rigidity by distension with fluid as movement of Oligochaeta, Polychaeta and Nematoda.

Q 23. What is book lung?
Ans. It is respiratory organ of some air breathing arachnids, consisting of projections containing blood and arranged like leaves of a book in a depression of body wall.

Q 24. Where is the food masticated in birds?
Ans. The food in birds is masticated in a thick muscular structure known as the gizzard.

Q 25. Name the protective embryonic membranes of reptiles.
Ans. These are the amnion, allantios and chorion.

Q 26. Distinguish oviparous animals from viviparous ones.
Ans. The animals which lay eggs are called oviparous e.g., birds while those which give birth to the young ones are known as viviparous. e.g., mammals.

Q 27. The teeth of some mammals asmon are known in two sets. Name them.
Ans. These are deciduous or milk set and the permanent teeth.

Q 28. In which geological period did the mammals become dominant?
Ans. The mammals became dominant in cenozoic period.

Q 29. How is malaria spread?
Ans. Malaria is spread by the bite of the female Anopheles mosquito.

Q 30. Differentiate between Anamniotes and Amniotes.
Ans. Anamniotes: The animals without fetal membrane for exp Cyclostomata, Chondrichthyes, Osteichthyes and Amphibia known as anamniotes.
Amniotes: The animals with fetal membranes for exp reptilia, aves and mammals are called amniotes.

Written By: Asad Hussain