A HANDBOOK OF PLUS TWO BOTANY Based on
A HANDBOOK OF PLUS TWO BOTANY Based on the Latest SCERT Grading Curriculum CLASS XII (Higher Secondary, VHSE & CBSE) M. M. SABU M. Sc, M. Phil. , B. Ed. (St. Peter's Higher Secondary School Elanji, Ernakulam District) Onscreen presentation: Brainwave, Thiruvananthapuram 1
CONTENTS Unit-wise Weightage & Year Plan for Learning Distribution of scores for higher secondary examination - Botany UNIT ONE: REPRODUCTION Chapter 1. Reproduction in Organisms 2. Sexual Reproduction in Flowering Plants UNIT TWO: BIOLOGY IN HUMAN WELFARE 3. Strategies for Enhancement in Food Production UNIT THREE: BIOTECHNOLOGY 4. Biotechnology: Principles and Processes 5. Biotechnology and its Applications UNIT FOUR: ECOLOGY 6. Organisms and Populations 7. Ecosystem 8. Environmental Issues Higher Secondary Examination March 2012 Questions & Answers 5 67 182 244 326 381 506 607
CHAPTER -1 REPRODUCTION IN ORGANISMS 06 07 08 09 12 15 16 17 19 22 28 28 29 31 36 Chapter - 1 3 Life Span Reproduction Asexual reproduction Mode of asexual reproduction in organism Important Vegetative Propagules: Sexual reproduction Reproductive phase Cyclic Changes in reproductive phase of mammals Events in sexual reproduction Homothallic and Heterothallic Gamete transfer in seed plants II. Fertilisation (Syngamy) External fertilisation and internal fertilisation Post fertilisation events PREVIOUS YEARS' HSE QUESTIONS
Life Span Life span is a period for which an organisms lives i. e. , from birth to natural death and it is not necessarily correlated with the sizes of organisms. The life span of different animals and plants is as follows: - One day - 4 -5 months - 200 years - 3000 -4000 years - 26 Years - 20 -30 years - 65 years - 90 years - 100 years Parrot Tortoise Fruit fly Butterfly Crow Crocodile Rice plant Rose bush Cow Banana tree - 140 years - 150 years - 10 -12 days - 1 -2 weeks - 15 years - 60 years - 3 -4 months - 4 years - 20 -30 years - 10 years Chapter - 1 4 Mayfly Wheat Banyan (Ficus) Sequoia Monkey Dog Horse Elephant Eagle Man
5 5 Chapter - 1 The male gamete is small, motile with one or two flagella, commonly called antherozoid or sperm. The female gamete is large, non-motile without any flagella. It is called egg or ovum. Majority of sexually reproducing organisms produce heterogametes. eg. , Homo sapiens.
Chapter - 1 6 Homothallic and Heterothallic Homothallic (Monoecious) / Bisexual / Hermaphrodite Organisms with both male and female reproductive structures in the same individual are called Homothallic. eg. , several fungi. Hermaphrodites: Bisexual animals which possess both male and female reproductive organs are called hermaphrodites. Eg. Earthworms, sponge, tapeworm and leech. Monoecious: A plant bearing male and female flowers is known as monoecious. Eg. Cucurbits and coconuts Heterothallic / dioecious / unisexual If the male and female reproductive structures are seen in different thalli, the plants are said to be heterothallic. Heterothallic plants are dioecious and unisexual. In animals 6 cockroach is unisexual.
Dioecious: When the male and female flowers are found on different plants, the plants are said to be dioecious Eg. Papaya and data palm. Chapter - 1 7 (a) Bisexual animal (Earthworm) (b) Unisexual animal (Cockroach) 7
(c) Monoecious plant (Chara) (d) Dioecious plant (Marchantia) (e) Bisexual flower (Sweet potato) Unisexual Flowers: Flowers having either male or female reproductive structures are called unisexual flowers. They are of two types staminate & pistillate. Chapter - 1 8
Staminate (Male flower): The flower having male reproductive structure {stamens) is called staminate flower. Pistillate (female flower): The flower having female reproductive structure (Pistil) is called pistillate flower. 9 Gametes are always haploid (n). In haploid organisms, the gametes are produced by mitotic division, eg. , monera, . fungi, algae and bryophytes. In diploid organisms, the gametes are produced by meiotic division, eg. , pteridophytes, gymnosperms, angiosperms, most of the animals including human beings. Chapter - 1 Cell division during gamete formation
Chromosome numbers in Meiocytes (diploid, 2 n) and Gametes (haploid, n) of some organisms Chromosome Number in meiocyte (2 n) in gamete (n) Human beings 46 23 House fly 12 6 Rat 42 21 1 Dog 78 39 0 Cat 38 19 Fruit fly 8 4 Ophioglossum (a fern) 1260 630 Apple 34 17 Rice 24 12 Maize 20 10 Potato 48 24 Butterfly 380 190 10 Onion 32 16 Name of organism Chapter - 1
11 Chapter - 1 1 1 2. Gamete transfer v In most of the organisms male gamete is motile and the female gamete is stationary v Both the gametes are motile in some fungi and algae v In lower plant group like algae, bryophytes, and pteridophytes the gamete transfer occurs through water medium. v Large member of male gametes are produced to compensate the loss during the transfer.
(ii) (iii) Bacteria Virus S. No 1 2 Diseases caused Brown rust of wheat, red rot of sugarcane, late blight of potato Black rot of crucifers Tobacco mosaic, turnip mosaic Methods of Breeding for Disease Resistance There are two methods for carrying out breeding: (i) Conventional breeding techniques (hybridisation and selection) (ii) Mutation breeding Chapter - 3 (i) Causative Organism Fungi
(i) Conventional breeding method v It is carried out by the following steps: (a) Screening of germplasm for disease resistance. (c) Selection and evaluation of hybrids. (d) Testing and release of new varieties into the market. v Following are some of the varieties developed by above mentioned method: Chapter - 3 1 3 (b) Hybridisation of selected plants.
Chapter - 3 1 4 Crop Variety Resistance to Diseases Wheat Himgiri Leaf and stripe rust, hill bunt Brassica Pusa swarnim (Karan rai) White rust Cauliflower Pusa shubhra, Pusa snowball K-l Black rot, curl blight black rot Cowpea Pusa komal Bacterial blight Chilli Pusa sadabahar Chilly mosaic virus, tobacco mosaic virus, leaf curl
1. Questions 1 5 NCERT TEXT BOOK QUESTIONS Explain in brief the role of animal husbandry in human welfare.
CHAPTER - 4 BIOTECHNOLOGY: PRINCIPLES AND PROCESSES 246 249 252 253 262 263 266 267 269 275 281 292 297 Chapter - 4 1 6 Principles of biotechnology Creation of recombinant DNA Use of Gene Cloning Tools of recombinant dna technology Style of DNA Cleavage Separation and Isolation of DNA Fragments Cloning Vectors p. BR 322 Features of a cloning vector Gene transfer Processes of recombinant DNA technology Bioreactors PREVIOUS YEARS' HSE QUESTIONS 16
Chapter - 4 1 7 Biotechnology deals with technique of using live organisms or enzymes from organisms to produce products and processes useful to humans. Old biotechnology deals with the techniques in biotechnology based on the natural capabilities of micro -organisms, eg: preparation of wine, beer, and other alcoholic beverages, vinegar, cheese, curd etc. All are microbe-mediated processes. Modern Biotechnology Modern biotechnology deals with the techniques based on genetic engineering. The important techniques included under modern biotechnology are: 1. 'test tube' baby.
Chapter - 4 1 8 2. Synthesising a gene and using it. 3. Developing a DNA vaccine. 4. Correcting a defective gene. In 1978, the European Federation of Biotechnology (EFB) has given a definition that encompasses both traditional biotechnology and modern molecular biotechnology. The definition given by EFB is as follows: "The integration of natural science and organisms, cells, parts thereof, and molecular analogues for products and services. " I. PRINCIPLES OF BIOTECHNOLOGY The two core techniques that enabled the birth of modern biotechnology are:
Chapter - 4 1 9 The naturally-occurring plasmid in E. coli is called Col E 1 and in Agrobacterium tumifaciens is called Ti plasmid. Naturally-occurring plasmids may not possess all the properties of a suitable cloning vector. Therefore, it may be reconstructed by inserting certain other genes. The important commercial artificiallyreconstructed plasmid from the natural plasmid of E. coli (Col Ej) are p. BR 322, p. UC-18, etc. p. BR 322 It is an artificially-reconstructed plasmid vector from the plasmid of E. coli (Col E 1) During its reconstruction, 3 genes are added to Col E 1 1. ori - It is the gene for starting replication. 2. tet. R - It is the gene for tetracycline resistance.
3. Chapter - 4 2 0 amp. R- It is the gene for ampicillin resistance. tet R and amp. R are called the selectable markers. p. BR 322 is the first artificial cloning vector developed in 1977 by Boliver and Rodriguez from E. coli plasmid. 'p' refers to plasmid, 'B' to Boliver are 'R' to Rodriguez.
Chapter - 4 2 1 E-coli cloning vector p. BR 322 showing restriction sites (Hind III, Eco RI, Bam HI, Sal I, Pvw II, Pst I, C 7 a I), ori and antibiotic resistance genes (amp 11 and tet. R) and rop codes for the proteins involved in the replication of the plasmid.
The ligation of foreign DNA is carried out at a restriction site (cloning site) present in one of the two antibiotic resistance genes, eg. in the vector p. BR 322, alien DNA is ligated in the area of Bam HI site of tetracycline resistance gene. Such recombinant plasmid will lose tetracycline resistance due to insertion of foreign DNA. Selection of recombinants v Selection of recombinants formed can be done by one of the following methods. (a) Inactivation of antibiotics v If a foreign DNA ligates at the Bam HI site of tetracycline resistance gene in the vector p. BR 322, the recombinant plasmid loses the tetracycline resistance due to insertion of foreign DNA. v Chapter - 4 2 2
Chapter - 4 2 3 4. Insertion of recombinant DNA into the host cell or host organism The ligated DNA is introduced into the recipient cells by making them 'competent' to receive (take-up) DNA present in its surrounding. v If recombinant DNA carrying antibiotic resistance (e. g. ampicillin) is transferred into E. coli cells, the host cell is transformed into ampicillin resistant cells. v The ampicillin resistant gene (amp. R) in this case is called a selectable marker. v On growing transformed cells on agar plates containing ampicillin, only transformants will grow and untransformed recipient cells will die.
CHAPTER - 5 BIOTECHNOLOGY AND ITS APPLICATIONS 327 Biotechnological applications in agriculture Production of pest-resistant plants Biotechnological applications in medicine Gene therapy Molecular diagnosis Transgenic ANTJV: LS Ethical issues Biopiracy PREVIOUS YEARS' HSE QUESTIONS 328 331 337 341 344 347 351 353 355 Chapter - 5 2 4 Applications of Biotechnology 24
Chapter - 5 2 5 Applications of Biotechnology The important applications of biotechnology arc: (i) therapeutics (ii) diagnostics (iii) genetically modified crops for agriculture (iv) processed food (v) bioremediation (vi) waste treatment (vii) energy production Critical research areas in biotechnology There are 3 critical research areas in biotechnology. They are: 1. Catalyst: To supply best catalyst (microbe or pure enzyme) in the form of organism with better characteristics.
CHAPTER - 6 ORGANISMS AND POPULATION 382 385 388 389 396 407 410 414 426 433 444 457 458 462 463 465 470 471 Chapter - 6 2 6 Ecology Organisms and its environment Components of a habitat Major abiotic factors Responses to abiotic factors Adaptations Symptoms of altitude sickness Population growth forms / models Population interactions Gause's Competitive exclusion principle Parasitism Brood Parasitism Commensalism Mutualism Amensalism PREVIOUS YEARS' HSE QUESTIONS 26
Chapter - 6 2 7 Ecology is the branch of biology that deals with the study of interaction between organisms and their environment. The word ecology was given by a German biologist, Ernst Haeckel in 1869. The word is derived from the Greek word Oikos meaning 'home', and logos meaning to study'. Prof. Ramdeo Misra is considered as the "Father of Ecology in India" for his great contribution in the field of ecology in India. Levels of Organisation in Ecology is basically concerned with four levels of biological organisation, organisms, populations, communities and biomes
Chapter - 6 2 8 (i) Adaptation in Kangaroo rat v The Kangaroo rat in North American deserts is capable to meet its internal water requirement by oxidation of fat (metabolic water) where water is a by-product. v It has the ability to concentrate its urine (solid urine) for minimum loss of water through excretory products. (ii) Adaptation in desert plants (i) called cuticle, for minimum loss of water through transpiration.
Chapter - 6 2 9 Where d is the rate of change, N is the number of existing individuals, t is the time and r is the intrinsic rate of natural increase d. N/dt represents the rate of change in population size. By applying the basic calculus, we can derive the integral form of the exponential growth equation as, Nt = N 0 ert Where, Nt = Population density after time t N 0 = Population density at time zero (at beginning) r = intrinsic rate of natural increase (B-D) e = the base of natural logarithms (=2. 71828)
3 0 Darwin, who development theory of natural selection, calculated that even a slow-growing animal like elephant could reach unlimited numbers in the absence of checks. Chapter - 6 If any species is growing exponentially under unlimited resources it can reach enormous copulation densities in a short time.
Chapter - 6 3 1 Population growth curve: 'a' when responses are not limiting the growth, plot is exponential, 'b‘ when responses are limiting the growth, plot is logistic. 'K‘ is carrying capacity.
PREVIOUS YEARS' HSE QUESTIONS 1. Interspecific interaction arise from the interaction of populations of two different species. If we assign + for beneficial, - for detrimental and 0 for neutral interactions, copy and complete the following chart. 3 2 Species A --------------------+ Species B -------------------- Name of interaction Mutualism ----------Commensalism Amensalism -------------- Questions (HSE March 2012) (4 scores)
Ans: 2. Species B + + - 0 0 Name of interaction Competition Parasitism/Predation Given below is the bar diagram showing age structure of three different population. Observe the diagram carefully and answer the following questions. (a) Select the stable population (b) Compare the nature of population growth in A, B, and C (HSE March 2011) (3 ½ scores) Ans: (a) B Questions 3 3 Species A +
A Expanding Positive growth 2. B Stable O-growth C Declining -ve growth Given below is a table which shows the interspecific interaction. '+' sign indicates beneficial, '-' sign indicates detrimental and '0' indicates neutral. (a) Fill in the blanks Questions 3 4 Ans: (a) B
Species A 0 + Species B 0 Interaction Competition -------------- 3 5 (HSE March 2010) Ans: a) 0 - Amensalism, + 0 Commensalism b) Predation/ Parasitism 4. Given below a schematic representation with circles and squares, which shows four factors/processes influence the population density. Write the positive factors in circles and negative factors in squares. (HSE March 2010) (2 Scores) Questions b) Name the interactions where one species detrimental.
Ans: In Circle Natality (+), Immigration (+) v In square-mortality (-), Emigration (-) 5. Two students, Unni and Kannan studied inter specific interactions between different species. They made a table assigning a '+' for beneficial interaction, '-' for detrimental and '0' for neutral interaction. Can you help them by naming the interaction between species in different cases? Write one example for each interaction. (HSE SAY 2010) Questions 3 6 v
Chapter -7 3 7
1. ECOSYSTEM STRUCTURE AND FUNCTION The ecosystem consists of biotic and abiotic components and their interaction with each other results in a physical structure. v The flow energy takes place within these components of the ecosystem. Structure of ecosystem Each ecosystem has a characteristic physical structure. It is the result of the interaction of biotic and abiotic components in the ecosystem. An ecosystem has two structural features (i) species composition and (ii) stratification, Chapter -7 3 8 v
Chapter -7 3 9
2. PRODUCTIVITY The rate of biomass, or organic matter produced during a given period of time is called productivity. Productivity is of two main types (1) Primary Productivity and (2) Secondary Productivity, (1) Primary Productivity v The rate of biomass production per unit area over a time period by plant during photosynthesis is called primary productivity. v The productivity is expressed in terms of weight (g -2) or energy (K calm-2) Chapter -7 4 0
1. 2. 3. 4. Gaseous cycle The reservoir is the atmosphere The nutrient occurs as gas or vapour It is comparatively quick or fast Example: carbon cycle, nitrogen cycle Sedimentary Cycle The reservoir is the earth crust The nutrient is non-gaseous It is quite slow Example: phosphorus cycle, sulphur cycle Chapter -7 4 1 2) Sedimentary cycle In the sedimentary cycle, the reservoir for the nutrients is in the sediments of earth crust. Elements such as phosphorus, calcium, sulphur and potassium have sedimentary cycles. The sedimentary cycles are very slow and less perfect system in that the elements may get locked in the reservoir.
Chapter -7 4 2 Simplified model of carbon cycle in the biosphere
8. Thefollowingfigureshowsaphosphoruscyclemodelina terrestrial ecosystem. Answer the following questions. (a) ecosystem? (b) organisms? Questions 4 3
CHAPTER-8 ENVIRONMENTAL ISSUES 608 611 620 623 625 628 630 634 636 637 641 643 648 649 651 652 654 662 669 672 675 Chapter - 8 4 4 Pollution Kinds of pollution Controlling Vehicular Air Pollution: A Case Study of Delhi New Auto Fuel Policy Noise pollution Water pollution and its control Effects of water pollution Algal bloom Biomagnification Eutrophication A Case Study of Integrated Waste Water Treatment Solid wastes Remedy for plastic waste: A case study Agro-chemicals and their effects Organic Farming : A case study Organic farming Case Study of Organic Farming Radioactive wastes Greenhouse effect and global warming Ozone depletion in the stratosphere Deforestation Case Study of People's Participation in conservation of forests PREVIOUS YEARS' HSE QUESTIONS 44
Chapter - 8 4 5 1. POLLUTION ♦ Pollution is defined as an undesirable change in physical, chemical or biological characteristics of air, land, water or soil. ♦ Pollutants are the agents which bring about an undesirable change in the properties of air, water and soil. ♦ Environment (Protection) Act, 1986 to protect and improve the quality of environment (air, water and soil) Pollutants The substances or agents which bring about pollution are called pollutants.
Chapter - 8 4 6
Questions 4 7
Species A Species B + + Name of interaction 1 1 4 scores Competition + - Parasitism / predation 10. a. Recognition sequence /Restriction sites /Palindromic sequence / cloning sites. b. Ligase / DNA ligase / molecular glues c. Preparation of competent host Direct gene transfer by genegun (biolistics) Direct gene transfer by microinjection Using cloning vectors Using disarmed pathologens OR - Antibiotic resistance - selectable markers - explanation 1 1 I + 1 4 Scores 2 Questions 4 8 0 0
- Insertional inactivation - colour reaction - explanation 4 Scores Questions 4 9 2
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