Yr 1 1st Term Biology PDF

Subject : BIOLOGY Term: FIRST TERM Session : 2023/2024 School: CHRISLAND SECONDARY SCHOOLS Class : YEAR 10 Educator :  TABLE OF CONTENT 1ST TERM WEEK 1: SCIENCE OF LIVING THINGS WEEK 2: SCIENCE OF LIVING THINGS WEEK...

Subject : BIOLOGY Term: FIRST TERM Session : 2023/2024 School: CHRISLAND SECONDARY SCHOOLS Class : YEAR 10 Educator :  TABLE OF CONTENT 1ST TERM WEEK 1: SCIENCE OF LIVING THINGS WEEK 2: SCIENCE OF LIVING THINGS WEEK 4: CLASSIFICATION AND WEEK 3: CLASSIFICATION OF LIVING THINGS IDENTIFICATION OF LIVING THINGS WEEK 5: ORGANIZATION OF LIFE WEEK 6: PLANT NUTRITION WEEK 7: MID- TERM WEEK 8: PLANT NUTRITION WEEK 9: ANIMAL NUTRITION WEEK 10: REVISION WEEK 11: WEEK 12: WEEK 13:  OBJECTIVES At the end of the lesson, students should be able to:  Define Science  Give a comprehensive definition of Biology  State the branches of Biology  Highlight the relevance of Biology to man  Enumerate the scientific methods of enquiry.  Science is an organised body of knowledge which uses a systematic approach of study.  This systematic approach is called scientific method.  Biology is the SCIENTIFIC study of living things.  The study of life.  The word Biology came from two greek words-’’Bios’’ meaning Life and ‘’Logos’’ meaning study. The three major branches of Biology are 1. Botany: Study of plants. 2. Zoology: Study of animals. 3.Microbiology: Study of micro-organisms Leeuwenhoek is considered as the father of microbiology. No. Branches Description This involve the identification and classification of 1 Taxonomy the living species. 2 Histology Histology is the study of the behavior of tissues 3 Anatomy The study of the internal body parts. The study of the external body parts of different 4 Morphology living species. 5 Cytology The study of the functions and structure of cells. Molecular The study of different activities of protoplasm, 6 Biology including their functions, structures etc. The study of the functions and processes of 7 Physiology different body parts. 8 Embryology It is the study of embryonic development The study of the relation of living organism with 9 Ecology their living environment. No. Branches Description The study of the inheritance/heredity from 10 Genetics generation to generation. 11 Evolution The study of life & its existence. It studies fossil fuels and develops techniques to 3 Palaeontology identify these resources underneath. 14 Haematology It is the study and treatment of blood. 15 Virology This branch is all about the study of viruses  Find out the meaning of :  --Parasitology  --Biochemistry  --Agronomy  --Araneology  --Dermatology  --Entomology  -- Eugenics I. Observations, II. Identifying a problem/asking questions. II. Put forward a possible hypothesis (scientific guess) III. Designing and conducting experiments to test the hypothesis. IV. Analyse results and draw conclusions. V. Accept, reject or modify hypothesis. VI. Share the results with other scientists who also test the hypothesis, and verify it.  Vii) The hypothesis becomes a THEORY after it has been tested and found to be repeatedly correct within the limits of available evidence.  Viii) Theory becomes A LAW OR PRINCIPLE if it has been extensively tested and proven to be true. NOTE: HYPOTHESIS------A hypothesis is a reasonable explanation for an observed natural phenomenon.  An experiment must be designed to eliminate all bias so as to avoid making false conclusions.  To do this, all factors(variables) affecting the result of the experiment must be kept constant(Control) except the one that is being tested.(Test experiment)  Such experiments are known as Controlled experiments.  In reporting any experiment, always ensure that you include the following features: 1. Aim: State the purposes of the experiment. 2. Apparatus: List the apparatus/material used. 3. Method: Describe in detail every step you took in performing the experiment [ possibly with diagrams] 4. Observation: Record all reactions or all that happened from the beginning to the end of the experiment. 4. Observation: Record all reactions or all that happened from the beginning to the end of the experiment. 5. Precautions: List all the steps you took to ensure you got accurate/fair result. 6. Conclusions: Draw conclusions from the results you obtained and your observation.  The usefulness of Biology to Man includes: 1. Development of medicine and vaccines. 2. Production and improvement of the quality of food. 3. Control of pollution, pests and diseases. 4. In-vitro fertilization,. 5. Biotechnology : genetic engineering, 6. Organ transplant; blood transfusion 7. Production of hormones e.g Insulin, etc 1. Define science 2. Mention the five basic Scientific methods. 3. What is scientific enquiry/investigation? 4. Explain briefly how you can carry out scientific enquiry 1. Describe an experiment [with diagrams],using the format of reporting an experiment: Aim, Apparatus,Method,Observation,Precaution and Conclusion. 2. Mention ANY 5 [ five] scientific laws /principles, stating the originators. Biology in SSCE consists of two papers 1. Paper 1 Practical 2. Paper 2 Objective and Theory. Papers and their weighting Marks Percentage Practical 80 40% Obj. 60 30% Theory 60 30% 200 100%  Living things are capable of carrying out the basic life functions. 1. M--Movement 2. R--Respiration 3. N—Nutrition/ Feeding 4. I—Irritability/ Sensitivity 5. G--Growth 6. E--Excretion 7. R—Reproduction Non-living things on the other hand are not able to carry out all these basic functions Movement is the change in position of parts or the whole body. Organisms move in order to search for food, mate, shelter, escape from danger, respond to stimuli etc. Respiration Respiration is the chemical break down of food(glucose) to release energy. There are two stages of respiration 1. External respiration or breathing 2. Internal or Tissue or Cellular respiration. Tissue respiration are of two types. 1. Aerobic tissue respiration-which requires oxygen. 2. Anaerobic tissue respiration- which does not require oxygen.  Nutrition is the obtaining, intake and use of food for energy, growth, and repairs of body tissues.. Irritability/Sensitivity. Irritability is the ability to respond to stimuli. Stimuli are changes which occur in the environment. Example of stimuli, Heat, Light, Gravity, Chemical substances, Hunger, Thirst, Touch etc Types of responses include 1. Tropism/ tropic movement. 2. Nastism/Nastic movement. 3. Taxism/Taxis movement. Excretion is the removal of waste products of metabolism from the body of an organism. Growth Growth is an irreversible increase in size ( height, weight etc). Reproduction Reproduction is the ability of an organism to produce young ones of the same kind. There are two types of reproduction 1. Sexual reproduction 2. Asexual reproduction.  Charac Plants Animals teristic s i Movemen No locomotion. Animals exhibit. t They move in locomotion. response to stimuli. 2 Nutrition Autotrophic nutrition Heterotrophic nutrition. ( Can manufacture [Use already-made food} their food) 3 Irritability a). Respond to a)Respond to stimuli stimuli slowly. quickly. b.) No sense organ Characte Plants Animals ristics 4. Growth Growth is apical Growth is intercalary and and unlimited limited. 5 Excretion a)Excretory organs a)Excretory organs are are absent present b)Most excretory b)They pass out their wastes are stored excretory wastes. 6 Cells Chloroplast and Cell Chloroplast and Cell wall wall are present are absent  Viruses are much smaller than bacteria. Can only be seen with the electron microscope.  They are the link between non-living and living matter because : 1. Outside a living cell they assume a crystalline non-living form. 2. They do not have cells or cell membrane , cell organelles and do not carry out the basic life functions. 3. They, however reproduce but inside another living cell (called the host). 4. They have DNA or RNA which contain hereditary information. NOTE: A Virus that attacks bacteria is called a Bacteriophage  A virus may be spherical, rod-shaped , tadpole-shaped, etc A virus consists of: 1. An outer coat made up of protein called CAPSID. 2. An inner core made up of genetic material DNA or RNA. Other structures a virus could have are: Envelope: consists of lipids. Tail--used for attachment. DNA: Deoxyribonucleic Acid RNA: Ribonucleic Acid  .  Animal diseases caused by Viruses 1. Measles 2. Poliomyelitis 3. Small pox 4. Chicken pox 5. Influenza 6. Yellow fever 7. Common cold 8. AIDS 9. Ebola, etc 1. Mosaic disease of tobacco, cassava, potato, tomato etc 2. Groundnut rossete 3. Swollen shoot of cocoa etc  Assignment 1. What is classification 2. Mention one scientist associated with classification 3. What is hierarchy in classification Classification means grouping or sorting. The science of classification is termed taxonomy/ systematics Organisms are classified based on common characteristics.  m/j 2017 no1  Carl Linnaeus was called the father of taxonomy. Hierarchies / Levels of classification. 1. Kingdom 2. Phylum(plu: phyla)/ Division in plants 3. Class 4. Order 5. Family 6. Genus(plu= genera) 7. Species. The highest level is the KINGDOM while the least level is the SPECIES A species is made up of organisms that are similar and interbreed freely, i. e, only one type of organism..  Binomial nomenclature is a system of giving two names to an organism. This system was developed by Carl Linnaeus. The first name is the generic (genus) name and begins with a capital letter. The second name is the Specific (species) name and begins with a small letter. The names are underlined separately or printed in italics. E.g.1. Man-----------------------Homo sapiens 2. Domestic dog-----------Canis familiaris 3. Maize plant--------------Zea mays 4. Grasshopper-------------Zonocerus variegatus 5. Lion-------------------------Panthera leo 6. Cat--------------------------Felis sylvestris 7. Rice-------------------------Oryza sativa 8. Rat---------------------------Rattus rattus 9. Common Lizard---------------- Agama agama 10. Pawpaw---------------------Carica papaya  All living things are classified into five kingdoms, namely: 1. kingdom Monera 2. Kingdom Protista (Protoctista) 3. Kingdom Fungi 4. Kingdom Plantae (all plants) 5. Kingdom Animalia (all animals)  Procaryotes  Cells that do not have well-defined nucleus, i.e nuclear membrane is absent e.g Bacteria. The nucleus is a strand of DNA.  Eucaryotes  Cells that have well-defined nucleus, i.e nuclear membrane is present e.g protists, fungi, plants and animals. - Examples include Bacteria, Blue-Green algae etc -Unicellular, -Procaryotic (prokaryotic) -Possess cell wall but not made of cellulose -They reproduce asexually by Binary fission ---They are unicellular and eukaryotic --Have simple cell structure Examples are Amoeba, Paramecium, Chlamydomonas, Euglena, etc Plant-like protists have cell walls and chloroplasts and are classified as Protophyta e.g Chlorella Animal-like protists do not have have cell walls and chloroplasts and are classified as Protozoa e.g are Amoeba, Paramecium, Plasmodium, Trypanosoma, etc They both have: - definite shape; - chloroplasts containing chlorophyll used to absorb light; - Paramylum granules; - Pyrenoid to store food in the form of starch. For Euglena  Gullet for feeding  Has flagellum for locomotion in water  Has Myonemes for movement.  Has pellicle that gives it a definite shape;  Has eye spot to detect light intensity;  Has contractile vacuole for osmo-regulation and excretion  It does not have a cell wall For Chlamydomonas Presence of: Flagella;  eye spot;  contractile vacuole -They are multicellular except Yeast which is unicellular. --Do not have chlorophyll ---Possess cell wall made of chitin. -Body, called MYCELIUM is made up of fine delicate threads called HYPHAE(Sing: Hypha). -Mostly Saprophytic , but some are parasitic in nutrition. Examples include, Yeast , Mushroom, Mould, Mucor, etc. -Reproduction is sexual or asexual(Sporulation in most fung budding in Yeast). Assignment Draw and label: 1. Rhizopus 2. Yeast cell  1. They are important decomposers. They help to return nutrients to the soil, i.e they recycle nutrients.  2. Yeast is used in the fermentation industries to produce alcohol  3. Yeast breaks sugar to produce carbon dioxide which make bread rise  4. Some fungi are edible e.g Mushroom  5. Some fungi cause diseases.  6. Some fungi are used to produce antibiotics e.g Penicillium  Main characteristics  --Multicellular  --Presence of cell wall  --Presence of chloroplast The kingdom Plantae consists of these phyla: 1. Phylum Thallophyta /Algae e.g Spirogyra , Seaweed, Red algae, etc 2. Phylum Bryophyta e. g. Liverworts, Mosses 3. Phylum Tracheophyta e.g ferns, spermatophytes SEE THE WHITE BOARD FOR THE DIAGRAM 1. They are aquatic and do not have vascular tissues (i.e, they are non-vascular) 2. Body may be flat (Thallus) or filamentous like Spirogyra 3. Do not have roots, stem and leaves. 4. May reproduce sexually and asexually. -Other examples: Seaweeds( red and brown algae) e.g Kelp Assignment Draw Spirogyra  SPIROGYRA --They do not have vascular tissues Have no true roots, they have rhizoids instead of roots, They have stem and leaf like structures.. May reproduce sexually or asexually -Example –Mosses, Liverworts. -Tracheophytes are the vascular plants, they possess conducting /vascular tissues (xylem for transporting water and phloem for transporting food). -They have true roots, stems and leaves. - -Have true roots, stem and leaves. -They are vascular plants. -Conducting tissues are not well developed -Reproduce with special gametes and spores. The spores are located in sporangia on the undersides of the leaves. A group of sporangia is called a SORUS (plu= sori). -Example- Ferns, Selaginella.  -These are seed producing plants -They are vascular plants. -They are of two types: 1. Gymnospermae 2. Angiospermae - They bear ‘naked seeds’ in cones. - They do not bear flowers and fruits. -They have true roots, stems and leaves. -Possess needle -like leaves. -Examples: Cycads, Ginkgo, Fir, Pine, cedars, etc.  -The flowering plants. -Have true roots, stem and leaves. -Seeds are enclosed in fruits. -Angiosperms are of two types: 1. Dicotyledons 2. Monocotyledons (considered the most advanced plants) Organ/ Monocotyledon Dicotyledon feature Seed One seed leaf(cotyledon) Two seed leaves/ two cotyledons Root Fibrous/Adventitious roots Tap roots Leaf a) Parallel veins a) Net veins b) Narrow b) Broad flower Floral parts are three or Floral parts are in fours or multiples of three fives Stem Vascular bundles are Vascular bundles are scattered arranged in a ring Secondary Absent Present growth or secondary thickening Examples Grasses,Rice, Maize, Bamboo, Bean , Mango, Hibiscus, Oil palm Melon  Lichens can not be classified into any kingdom because a lichen is made up of an alga and a fungus. The alga makes food which it shares with the fungus.  The fungus absorbs water and provide shelter or the alga, thereby, protecting it from drying up.  This association is called Mutualism/ Symbiosis.  Lichens are found on tree barks, rocks, etc  Animals are multicellular. They do not have cell wall and chloroplasts Common Terms 1. Acoelomate – organism has no body cavity 2. Pseudo-coelomate—has false body cavity 3. Coelomate- has true body cavity 4. Coelom –body cavity 5. Bilateral symmetry—can be divided into identical halves by only one plane that passes through the center of the animal’s body. 6. Radial symmetry--- can be divided into identical halves by any plane that passes through the center of the animal’s body. 7. Diploblastic– body wall has two layers 8. Triploblastic—body wall has three layers. 9. Invertebrates–---- animals without backbone 10. Vertebrates----– animals that have backbone Phylum Symmetry Coelom Cellular Prominent members organization Porifera/ Asymmetric Acoelomate No tissues Euspongia, Spongilla Sponges al (No symmetry) Coelentrata Radial Acoelomate Tissues Hydra , Jelly fish, Sea anemone, Corals Platyhelminthe Bilateral Acoelomate Organ Tapeworm, Flukes, s/ Flatworms Planaria Nematoda / Bilateral Pseudo- Organ Ascaris, Hookworm Roundworms coelomate Annelida Bilateral Coelomate Organ-System Earthworm, Leech Mollusca Bilateral Coelomate Organ-System Snail, Octopus, Squid, Oysters, Clam Arthropoda Bilateral Coelomate Organ-System Insects, Spider,  ADDITIONAL FEATURES OF INVERTEBRATE GROUPS  1. These are simple multicellular aquatic animals.  2. They are diploblastic (and cylindrical).  3. They are hermaphrodites (have male and female sex organs).  4 They also reproduce asexually by budding.  5. Possess stinging cells called nematoblasts for defence and capturing prey   --Possess, flat bodies, Tapeworm is segmented  --Have only one body opening serving as the mouth and the anus.  --Mainly hermaphrodites. Parasitic but few, like Planaria, are free living  Phylum Nematoda (Round worms) Possess soft, smooth cylindrical, unsegmented bodies. ----Body pointed at both ends ---Has two body openings, mouth and anus ----Mainly parasitic ---Sexes are separate - These are the true worms with body segments.  - They are segmented.  - Have moist skin rich in blood capillaries. Possess chetae on body segments for movement. They are mainly hermaphrodites -Examples: Earthworm, Leech, etc.  They have soft, unsegmented bodies divided into distinct head, body mass and visceral organs. muscular foot for movement. There are two pairs of tentacles.  Body protected by hard calcareous shell, They are mainly hermaphrodites. -Examples: Land snail, squids, Slugs, Octopus, Oysters etc. 1.Presence of jointed appendages such as jointed legs, jointed antennae 2. Have segmented bodies 3. Bodies covered with exoskeleton made of chitin Functions—a) It prevents the animal from drying out(dessication) b) it protects it from mechanical injury 4. Body is divided into head, thorax and abdomen( head and thorax are fused in Arachnida and Crustacea) ECDYSIS/MOULTING: the process during which arthropods shed their exoskeleton (at intervals) to enable them grow.  It consists of four (4) classes namely: 1. Class Insecta e. g Cockroach, Grasshopper, Housefly, Mosquito, 2. Class Crustacea e. g Crab, Prawn, Lobsters, Water fleas 3. Class Arachnida e. g Spider, Scorpion, Tick, Mite 4. Class Myriapoda e. g Millipede and Centipede  1.Presence of jointed appendages such as jointed legs, jointed antennae  2. Have segmented bodies  3. Bodies covered with exoskeleton made of chitin  Functions—a) It prevents the animal from drying out(dessication)  b) it protects it from mechanical injury  4. Body is divided into head, thorax and abdomen( head and thorax are fused in Arachnida and Crustacea)   ECDYSIS/MOULTING: the process during which arthropods shed their exoskeleton (at intervals) to enable them grow.  - Insects are arthropods with 3 pairs of walking legs. - Have three body segments, head, thorax and abdomen - Three pairs of jointed legs. - Pair of compound eyes - A pair of wings - A pair of antennae or feelers - Examples:  Cockroach  Mosquito  Grasshopper  House fly, etc. CHARACTERISTIC INSECTA CRUSTACEA ARACHNIDA MYRIAPODA Body division Three Two Two Three (Head, Thorax (Cephalothorax and (Prosoma and (Head, Thorax and and Abdomen) abdomen) Opisthosoma) Abdomen Wings Present Absent Absent Absent Jointed walking legs 3 pairs 5 pairs 4 pairs Numerous Centipede- a pair per segment Milipede– two pairs per segment Swimming legs Absent Present Absent Absent (Swimmerets ) Jointed antennae 1 pair 2 Pairs None 1 pair Eyes A pair of A pair of stalked Eight simple eyes Most millipedes-have a compound eyes compound eyes pair of compund eyes made of several simple eyes[ocelli] Some centipedes- have simple eyes, some have compound eyes Eyes may even be absent Respiratory organ Tracheae Gills Book-lungs Tracheae Spinneret Absent Absent Present Absent –to produce silk threads -Mainly marine -Have spiny skin -Presence of tube feet for movement  These are animals with notochord at the embryo stage. SUBPHYLUM VERTEBATA Animals that have back bone or vertebral column It consists of the following: 1. Superclass Pisces/ Fish which is subdivided into: a. Class Osteichthyes(Bony fishes)–e,g Tilapia, Catfish, b) Class Chondrichthyes(Cartilaginous fishes ) e.g Shark, Rays, and Skates. 2. Class Amphibia, e.g. Toad, Frog, Newt, Salamander. 3. Class Reptilia, e.g. Lizard, Snakes, Crocodile 4. Class Aves/Birds, e.g. Parrots, Pigeon, etc. 5. Class Mammalia, e.g. Man, Bat, Whale, Lion, Rat, Dog, Hippopotamus, etc Characteristics ---Feed their young with milk from mammary glands ----They give birth to their young ones alive(Viviparous) i.e, they do not lay eggs except duck-billed Platypus and Echidna ----Have hairs or furs on the body ---Have external ears or pinnae(Sing: Pinna) ----Have heterodont dentition ----Have sweat and sebaceous glands  COMMON TERMS  Homoiothermic or homeothermic--- warm- blooded (can regulate body temperature)  Poikilothermic--- Cold-blooded (cannot regulate body temperature)  Viviparity----- Animal does not lay eggs i.e, gives birth to their young ones alive.  Oviparity—---- Animal lays eggs  Ovoviviparity—eggs hatch inside the mother before it is born e,g certain snakes Question: State four observable features of a cockroach Answer: - Three pairs of jointed legs. - A pair of compound eyes - A pair of wings - A pair of antennae or feelers  OBJECTIVES At the end of the lesson, students should be able to:  State the levels of organization of life and give examples in each case.  Highlight the advantages of complexity of structure in higher organisms  Discuss the disadvantages of complexity of structures in higher organisms.  Some organisms, like bacteria and protists, are unicellular (made entirely of one cell).  Some organisms, like fungi, plants, and animals, are multicellular (made of many cells).  In multicellular organisms, cells exhibit cell specialisation. They take on specific jobs and look different from each other. LEVEL OF DEFINITION and explanation EXAMPLES IN ANIMALS EXAMPLES IN ORGANISM ORGANIZATI PLANTS ON Macromolecul Made up of atoms and DNA, Proteins, Lipids, DNA, Proteins, e molecules etc Lipids, etc Organelle Made up of molecules and Mitochodria , Nucleus Mitochodria , macromolecules which carry Nucleus,Chloroplast out complex functions like respiration. Cell The basic unit of life. Blood cells, Muscle Epidermal cell, Amoeba, Made up of macromolecules cell, Egg cell, Sperm Mesophyll cell Paramecium, and organelles cell, Nerve cell, Euglena, Bacteria, Epithelial cell etc Tissue Made up of similar cells that Blood, Bone, Epidermis, Vascular Hydra, perform the same function Epithelium, tissues, Mesophyll, some algae and Muscle,Ligament, Parenchyma, fungi Cartilage, etc. Organ Made up of tissues that work Brain, Heart and Leaves, Stems, Flatworms, together to perform a specific Lungs, Eyes, Skin, etc Roots, Flowers, Roundworms, function rhizome, bulbs Mosses, etc Organ- Made up of organs that work Digestive system, Root system and Annelids, system together to perform a Nervous system, Shoot system Molluscs, ferns, specialized function. Excretory system, etc etc  NOTE--- THE ORGAN-SYSTEMS MAKE UP A COMPLEX MULTICELLULAR ORGANISM like Vertebrates,  Flowering plants. etc   ADVANTAGES OF COMPLEXITY IN HIGHER ORGANISMS   Death of a cell or cells cannot stop the function of the cells because of the large number of cells that perform a particular function..  They have the ability to perform complicated physiological functions.  There is division of labour between component parts.  It leads to efficiency of the organs and systems  It leads to increase in size because there are spaces between cells for growth  It increases adaptation to environment as they become resistant to adverse conditions.  Disadvantages of Complexity in Higher Organisms  Parts are interdependent, therefore, if one organ or organ-system is not functioning, the other organs or organ-systems cannot function properly.  Greater requirement for space, energy and environmental resources than single cell organisms..  There is a need for co-ordination of body parts and an efficient transport system. This is not required in unicellular organisms..  Complex organisms take more time to reproduce the younger ones.  It takes time for their younger ones to grow and mature.  ASSIGNMENT  1. State one function each of the following:  Red blood cell, White blood cell, Nerve cells, Epithelial cells, Sperm cell, Muscle cell  2a) Mention two types of tissues in : i) Plants ii) Man  Give two examples for each of the tissues you have listed in 2a.......: T1 WK 6  PLANT NUTRITION  Plants can make their food from simple inorganic substances. This is autotrophic nutrition  PHOTOSYNTHESIS  Definitions  1.. The process by which green plants make their food (glucose) from water and carbon dioxide in the presence of sunlight and chlorophyll  OR  2. The process by which green plants make their complex organic substances such as glucose from simple inorganic substances (such as water and carbon dioxide) in the presence of sunlight.  GENERAL EQUATION FOR PHOTOSYNTESIS   6 H2O + 6 CO2 sunlight C6H12O6 + 6 O2  Water Carbon Glucose Oxygen  Dioxide HOM E  CONDITION ROLE 1 WATER Source of hydrogen ions 2 CARBONDIOXIDE Reduced by hydrogen ions to glucose 3 SUNLIGHT Splits water molecules 4 CHLOROPHYLL Traps light energy 5 ENZYMES Catalyses the reactions 6 SUITABLE TEMPERATURE For optimum enzymatic actions  An experiment to show that photosynthesis occurs in green plants  Aim: to show that photosynthesis occurs in green plants  Apparatus--- Potted plant, Iodine solution, 70% Alcohol (Ethanol), white tile, water bath, Bunsen-burner, distilled water.  Method/ Procedure  Destarch the plant by putting it in a dark cupboard for 2 days  Place the plant in bright sunlight to enable it photosynthesize  After some hours, pluck a leaf and test it for starch as follows:  a) Put it in boiling water for half a minute to kill the protoplasm and burst the starch grains.  b) dip it in hot alcohol to decolourise it.  PRECAUTION  Hot alcohol must be in a water bath as it is flammable  Wash the leaf with warm water to soften it.  Place it on a white tile and add few drops of iodine solution to it   OBSERVATION---a blue-black colour is observed, indicating that starch is present  CONCLUSION-- photosynthesis occurs in green plants   MECHANISM OF PHOTOSYNTHESIS  Photosynthesis occurs in two main stages:  1, LIGHT REACTION OR LIGHT-DEPENDENT PHASE  It is also called ‘Photolysis of water’. It occurs during the day and It requires light.  Chlorophyll traps light energy and becomes energized  Light energy absorbed by chlorophyll is released to spilt water molecules into hydrogen ions and hydroxide/ hydroxyl ions.  2OH- + 2 OH- 2H2O + O2  Oxygen   Hydrogen ion is picked up by a coenzyme called NADP ( Nicotinamide Adenine Dinucleotide) to form NADPH  Hydroxide ions react with each other to form water and oxygen   2OH- + 2 OH- 2H2O + O2  Oxygen  The remaining energy trapped by chlorophyll is stored in ATP ( Adenosine Triphosphate). This is used in the dark phase.   DARK REACTION OR LIGHT-INDEPENDENT PHASE  It also occurs during the day but does not require light.  Hydrogen ion produced in the light phase reduces carbon dioxide into carbohydrate (glucose)  H+ + CO2 ( CH2O)n + H2O  Carbohydrate  IMPORTANCE OF PHOTOSYNTHESIS Photosynthesis is very important to both plants and animals in the following ways: (I) Production of food for both plants and animals. (II) It purifies the atmosphere by removing excess carbon dioxide from it. (III) It releases oxygen into the atmosphere for espiration by living things. (IV) Living thing need energy for metabolic activities. Photosynthesis is a means by which light energy is converted to usable energy (V) Photosynthesis provides building blocks for other food substances such as proteins, fats, oil, etc. HOM E EXPERIMENT II: TO SHOW THAT CARBONDIOXIDE IS NECESSARY FOR PHOTOSYNTHESIS Aim_ Apparatus: Procedure: - Set up the experiment as shown below. Expose it to sunlight for 2-6 hours. Obtain a leaf from each plant and test it for starch as stated in experiment 1. Observation:- Leaf from jar Y stains brown. Leaf from jar X turns blue black. Conclusion:- Carbon dioxide is necessary for photosynthesis. HOM E  EXPERIMENT III: TO SHOW THAT SUNLIGHT IS NECESSARY FOR PHOTOSYNTHESIS  Aim: To show that sunlight is necessary for photosynthesis.  Apparatus and Materials: well watered potted plant, black paper, / scalpel, pins/clip  Method / procedure: The set-up is as shown in the diagram below. Fix the black paper on the lower and upper surfaces 0f one of the leaves as shown in the diagram below.  The experimental set up is exposed to sunlight for 2-6 hours. The paper is removed and the leaf is tested for starch. HOM E Observation:- Parts of leaf covered with black paper stains brown. Parts of leaf exposed to sunlight turn blue black. These results indicate that starch is produced only in areas that received sunlight. Conclusion: sunlight is necessary for photosynthesis. EXPERIMENT IV: TO SHOW THAT CHLOROPHYLL IS NECESSARY FOR PHOTOSYNTHESIS Aim: To show that chlorophyll is necessary for photosynthesis. Apparatus and Materials variegated plant, ethanol, beaker, boiling tube, water, heat source, Iodine solution. Method / procedure: Leave the variegated plant in sunlight for 2-6 hours. Remove one leaf and make a labelled diagram of it to show the green and non-green parts. Test the leaf for starch as stated in experiment 1 HOM E Diagrams: HOM E Conclusion: Starch is made only in areas of the leaf with chlorophyll, showing that chlorophyll is necessary for photosynthesis. EXPERIMENT V: TO SHOW THAT OXYGEN IS GIVEN OFF DURING PHOTOSYNTHESIS Aims: To show that oxygen is given off during photosynthesis. Apparatus and materials: Beaker, short stemmed funnel, 2 thick wooden cubes, plastic, sodium hydrogen carbonate powder, test tube, water plant e.g. Elodea. (Spirogyra can be used too), glowing splint. Diagram: HOM E Method / procedure: Set up the experiment as shown above. Expose it to sunlight for about 2 hours. (The supports ensure circulation of air. Sodium hydrogen carbonate adds carbon dioxide.) Test any gas collected in the test tube using a glowing splint. Observation: A gas is collected in the test tube. The gas re-lights a glowing splint or makes it glow brighter. Conclusion: Oxygen is given off during photosynthesis. HOM E  1.Glucose is used for energy, materials for growth, reproduction, etc 2. The rest is converted to : a). Starch--- store in tubers, seeds, etc b). Proteins- for balding membranes, cell structures, hormones, enzymes etc c) Cellulose--- for cellwalls, d) Lipids--- for membranes; stored in seeds. and so on.  LIMITING FACTORS The factors affecting the rate of photosynthesis are called limiting factors. Light intensity- As light intensity increases, the rate of photosynthesis increases until it remains constant. Carbon dioxide concentration---- An increase in carbon dioxide concentration generally increases the rate of photosynthesis until it is limited by another factor. Temperature- Increase in temperature leads to the increase in the rate of photosynthesis. Above the optimum temperature, enzymes are denatured and the rate of photosynthesis decreases. Number of available chloroplasts HOM E........ : T1 WK 8 Plants require mineral nutrients or elements for proper growth and development. The soil is the main source of mineral salts while gaseous elements such as oxygen, hydrogen and carbon are mainly derived from the atmosphere. These elements are grouped into two classes, depending on the quantity required by the plants. They are as follows: (1) Macro- nutrients or Major elements or Essential elements (2) Micro- nutrients or Trace elements or non-essential elements. Macro- nutrients- These are elements required in large quantities for healthy growth of plants. Examples are calcium, oxygen, nitrogen, hydrogen, sulphur, iron, etc. Micro- nutrients- These are elements required in small quantities for healthy growth of plants. Examples are copper, boron, molybdenum, cobalt, manganese. zinc HOM E ELEMENTS FUNCTIONS DEFICIENCY SYMPTOMS Sulphur Formation of certain pe cellroteins Slender stem in t Yellowing of leaves (Chlorosis) Nitrogen Component of nitrogenous bases, Extremely stunted growth, proteins, chlorophylls Leaves become yellow (chlorosis) Phosphorus Component of nucleic acids, , Purplish leaves, adenosine Mottled leavs triphosphate (ATP), several Poor weedy growth coenzymes HOM E........ T1Wk8 ELEMENTS MAJOR FUNCTIONS DEDFICIENCY SYMPTOMS Potassium Regulation of csertain cell activities Poor growth, Leaves turn orange and brown Calcium Important in formation of cell walls, Poor growth activates enzymes Reduced root development Magnesium Component of chlorophylls, Chlorosis (Yellowing of leaves), Poor growth Iron Plays a role in chlorophyll synthesis Chlorosis (Yellowing of leaves), Poor growth HOM E  Mineral salts are dissolved in soil water and absorbed by plant roots. They are obtained from: 1. Sulphates, Phosphates, Nitrates/Ammonium salts in the soil 2. Salts of calcium, potassium, magnesium and iron.  Plant and animals need food for energy supply to carry out the life processes [e.g. movement, growth].  There are two major types of nutrition:  1. Autotrophic nutrition  2. Heterotrophic nutrition Autotrophic nutrition– a type of nutrition in which the organism is able to manufacture its own food. There are two types of autotrophic nutrition: 1. Holophytic nutrition(Photosynthetic): Green plants manufacture their food from water and carbon [iv] oxide by making use of light energy in the presence of chlorophyll. 2. Chemosynthetic nutrition: the organisms use energy obtained by breaking down chemical compounds to manufacture their food from simple inorganic substances like water, carbondioxide, ammonia, hydrogen sulphide e.g sulphur bacteria, nitrifying bacteria,etc.  In heterotrophic nutrition, the organism feeds on already-made food, i.e, it cannot make its own food. TYPES OF HETEROTROPHIC NUTRITION a) Holozoic nutrition b) Parasitic nutrition c) Saprophytic nutrition d) Carnivorous plants e) Mutualism or Symbiosis  a. Holozoic nutrition It involves feeding on solid organic substances. Food is ingested, digested and assimilated into the body It includes: i) Carnivorous feeding : Organism feeds on flesh only e.g. lion, cats, dogs, etc. ii) Herbivorous feeding : Organism feeds on plants only e.g. goat, sheep, Rabbit, etc. iii) Omnivorous feeding: Organism feeds on both plants and flesh e.g. man. Scavenging is a type of carnivorous feeding b) Parasitic nutrition: It is the type in which one organism called the parasite obtains food from another organism ( called the host) which suffers or dies in the process. Examples of parasites are: i)Plant parasites 1. Complete or total p arasites e.g Dodder (Cassytha filiformis) It cannot make its food so it depends on the host for water, mineral salts and food 2. Incomplete or partial parasites e.g mistletoe, It can make its food so it only depends on the host for water and mineral salts. Plant parasites have special sucking roots with Haustoria which penetrates the host’s stem ii)Animal parasites: 1. Endoparasites– which live within the host’s body e.g Tapeworm, flukes, plasmodium, roundworms, ticks, liver flukes, fleas, bugs, etc.. 2. Ectoparasites– which live outside the host’s body e.g ticks, lice, fleas, bugs, aphid, cotton stainer etc. HOM E c) Saprophytic nutrition : The organism obtains its food from dead and decaying organic matter, e.g. Putrefying bacteria, Saprophytic fungi, etc. The organism is called a decomposer. These are plants that obtain nitrogen by digesting the proteins in the bodies of insects. This is because they live in soils that are poor in nitrogen/ nitrates. They have bright colours to attract insects, structures for trapping insects and digestive juices , etc. Examples include Venus flytrap, Sundew(Drosera), Pitcher plant, Bladderwort (Utricularia), Butterwort, etc.  This is an association between two organisms called symbionts in which they derive benefits such as food, shelter and protection from each other.  Examples are 1) Legumes and nitrogen-fixing bacteria(Rhizobium), Plant provides shelter, bacterium makes nitrates/ ammonium compounds by fixing atmospheric nitrogen  2. Lichen (made. up of a fungus and an alga)  Refer to the previous notes  3 Bacteria in the intestines of herbivores and termites  Herbivore or the termite provides shelter and food source, Bacteria produce cellulose-digesting enzymes, etc  4. Sea anemone and hermit crab,  Having sea anemones living on its shell gives the crab an active defense against predators. All it has to do is retreat into the shell and let the stinging tentacles of the anemone ward off an attacker.  Riding around on the crab’s shell is advantageous for the anemones too.  The two animals share food, and being mobile allows an anemone to disperse its offspring more efficiently. ......: T2 An enzyme is an organic or a biological catalyst which speeds up chemical reactions in the living cells but is not used up in the process. Types of Enzymes Enzymes may be classified as:(i) Intracellular enzymes (ii) Extracellular enzymes. Characteristics of enzymes (i) Enzymes are catalysts (ii) Enzymes are proteins (iii) They are soluble (iv) They are specific for a particular substrate i.e, Pepsin can only act on proteins while Ptyalin will only act on starch.. (v) They are affected by the pH (acidity or alkalinity) of their surrounding. E.g Pepsin only works in an acidic medium (vi) They are sensitive to the temperature of their environment. At high temperatures , they are denatured or destroyed and at low temperatures, they do not function. In humans, the optimum temperature for an enzyme is 370C. (vii) They are usually involved in reversible reactions. (viii) They remain unchanged at the end of a chemical reaction. (ix) They can be activated by co-enzymes or inhibited by inhibitors. HOM E 1. Digestive enzymes ---help in breaking down foods to tiny absorbable units e.g proteins to amino acids, fats and oil into fatty acids and glycerol, carbohydrates into simple sugars such as glucose, fructose and galactose. 2.Respiratory enzymes ---involved in cellular respiration  BALANCED DIET Balanced diet is a diet that contains all classes of food substances in the right proportion and quantity. Classes of food Carbohydrates, Proteins, Fats and oils(Lipids), Vitamins, Mineral salts, Water. A balanced diet must contain roughages/ fibres as well. Importance of Balanced Diet  (1) It makes us to be healthy and resistant to diseases  (2) It provides energy for normal activities  (3) It prevents malnutrition diseases such as kwashiorkor in children  (4) It leads to growth and normal development of the body. 1. CARBOHYDRATES  Composition and Sources: carbohydrate is made up of carbon, hydrogen and oxygen. The ratio of hydrogen to oxygen is 2:1 as in the case of water. They have a general formula CX(H2O)Y.  Sources include yam, rice, bread, maize, millet, etc.  Types of Carbohydrates (i) Monosaccharide: They are referred to as reducing sugars or simple sugars. e.g. fructose, galactose and glucose (C6H12O6). (ii) Disaccharide: They are equally called complex sugars or non-reducing sugars. e.g. maltose, lactose and sucrose (C12H22O11). (iii) Polysaccharide: they are made up of many units of glucose linked together. They have the formula (C6H10O5)n.  Importance of Carbohydrates (1) Provides energy. (2) Used to build certain body parts e.g. exoskeleton in arthropods. (3) Components of mucus which is a lubricant in our body. 2.PROTEINS They contain carbon, hydrogen, and oxygen nitrogen, phosphorous and sometimes sulphur. Sources include egg-white(albumen), beans, soya beans, lean meat, fish, etc. Importance of proteins (1)To build new cells (growth) (2)Used for the repair of worn out tissues or cells (3)Used for the production of hormones and enzymes (4)For formation of membranes and other structures in the cell (5)Protect delicate organs DEFICIENCY OF PROTEINS 1. Kwashiorkor 2. Marasmus HOM E  They contain carbon, hydrogen and oxygen just like carbohydrates but of low oxygen ratio. They contain more calories of energy than carbohydrates.  Sources include butter, groundnut, palm oil etc.  Importance of lipids (1) Formation of membranes (2) Help in the maintenance of body temperature/ provide warmth (3) Provide energy to animals than carbohydrates.  Calcium, Phosphorous  Sodium Potassium, chlorine  Iron ,cobalt  Iodine  Manganese  Fluorine Calcium Milk, Component of bones Rickets in children cheese, and teeth, Softening of bones egg, helps in blood in cereals, clotting, muscle adults(Osteomalacia) meat, contraction, , vegetables Loss of muscle , fruits coordination etc. Phosphoro Milk, Formation of bones Rickets, us cheese, and teeth, osteomalacia Cereals, Component of eggs, fish, nucleic acids, meat etc. Sodium Maintain blood Improper muscle Potassium osmotic pressure, contraction; Table salt, chlorine Muscle contraction; Nervous disorder vegetables Conduction of nerve , fish, impulses; fruits, etc. Note– Excess sodium can lead to hypertension( High blood pressure) HOM E Minerals Sources Functions Deficiency symptoms Iron Liver, eggs, Formation of Anaemia; Cobalt cereals, pulses, haemoglobin in leafy red blood cells. vegetables, fruits etc. Iodine Sea foods, leafy Production of Goiter, vegetables, thyroxine. iodized salt etc. Manganese Liver, kidney, Normal Reproductive peanuts, etc reproductive failure; functions, menstrual cofactor for irregularities enzymes Fluorine Sea fish, Healthy teeth Dental caries. cheese, etc and gums Or tooth decay HOM E  Vitamins are required in small quantities.  These are:  (I) Water soluble vitamins, Vitamins B-complex and vitamin C  (II) Fat soluble vitamins, Vitamins A, D,E and K. VITAMINS SOURCES FUNCTIONS EFFECTS OF DEFICIENCY Vitamin A Palm oil, Good vision, good Night blindness (Retinol) fats, liver, skin and egg yolk, Xerophthalmia milk, vegetables, -Skin problems. etc. Vitamin B1 Whole Coenzyme for cellular Beriberi (Thiamine) grains, lean respiration pork, liver, eggs, dried Nervous coordination. beans,. Vitamin B2 Dairy Healthy skin, eye and Dermatitis, (Riboflavin) products, mucus membrane fish, Cracking of lips vegetables, and corners of eggs, beef, mouth,. cereals. Vitamin B6 , fish, Formation of amino Anaemia HOM vegetables, acids E Vitamin B3 Yeast, beans, Needed for cellular Pellagra (a skin (Nicotinic acid) milk, palm respiration disease) and wine, yam, digestive problems. vegetables, etc. Vitamin B12 Kidney, liver, Formation of red blood Pernicious anaemia (Cynacobalamin) fish, milk, cells etc. Vitamin C Fresh fruits Healthy dentine , Scurvy(bleeding (Ascorbic acid) and Aids wound healing. gum), poor wound vegetables Helps to resist infections healing and low resistance to infections Vitamin D Fish, milk, Strong bones and teeth. Rickets and (Calciferol ) egg, liver, osteomalacia. sunlight. Vitamin E Green Promotion of fertility in Sterility and (Ergosterol) vegetables, mammals. premature egg, butter, abortion. liver, etc. Vitamin K Green Aids blood clotting Haemorrhages i.e. (Phylloquinone) vegetables, inability of blood to especially HOM clot in time. cabbage and E  6. WATER Composition: Water is composed of hydrogen and oxygen. Sources of water Metabolic water from food, drinking water from rivers, taps, rain pond, etc. Importance of water (I) Water is the medium for metabolic reactions in the cells. (II) For the digestion of food. (III) Maintaining body temperature. (IV) About 80% of the body is water. (V) It aids excretion. (VI) It acts as a medium of transportation of nutrients. HOM E  Roughage is indigestible fibrous material derived form vegetables, fruits, carbohydrates and proteins.  Function– aids bowel movement by providing bulk to the food/ it prevents constipation.  Lack of roughage in the diet Causes constipation.  FOOD TESTS FOOD TEST OBSERVATION INFERENCE Carbohydrates: , add few drops blue-black Starch is (1) Starch of iodine colour. present. solution. (2) Reducing Add some Yellow/Orange/ Glucose or sugars/Simple benedict’s brick- red reducing sugar sugars (e.g. solution or precipitate is present glucose) Fehling solutions A and B, and heat. (3) Non- Add few drops Yellow/Orange/ Sucrose / reducing/ of dil. HCl and brick- red Complex/ non- Complex sugars boil, precipitate reducing sugar (e.g. sucrose) Add dil.NaOH is present. Add NOTE– HCl hydrolyses Benedict’s complex sugars to simple sugars or Fehling NaOH neutralizes excess acid. solutions, HOM E FOOD TEST OBSERVATION INFERENCE PROTEINS (a) Add Millon’s A white Protein is 1.Millon’s test reagent to egg precipitate which present albumen and quickly turns heat brick red. 2. Biuret Test. Add Biuret Purple or violet Protein is solution (made colour. present. of sodium hydroxide (NaOH) and Copper II Sulphate (CuSO4) solutions in drops, shake 3. Xanthproteic Add conc. A white Protein is test Trioxonitrate (v) precipitate present. acid(HNO3), heat, forms, which cool and add turns yellow on ammonia heating. HOM E FOOD TEST OBSERVATION INFERENCE FATS AND (a)Drop oil on a spot on Paper becomes Fat /Oil is OIL a filter paper, translucent. present Sudan III (b) Add few drops of Red colour is Fat /Oil is test Sudan (III) solution to observed. Black present. oil in a test tube, boil precipitate is the solution. formed on boiling. Emulsion Add some ethanol or White emulsion Fat / Oil is test for sodium hydroxide present fats solution. Add some water and shake, WATER Dip a blue, dry cobalt Paper changes Water is present. chloride paper in a food from blue to item. pink. HOM E  ASSIGNMENT: CLASS ACTIVITIES: 1.Mention the six classes of 1. State six modes of food, state one function of nutrition each 2. Explain any four of the 2. Write one function and nutrition types stated in one deficiency symptom of: question one. a)Vitamins 3. Give two examples each A,D,K,B1,B3,B12,C of the following b) Iron, Calcium,Iodine, organisms: Fluorine, Sodium. (i) Autotrophs (ii)Parasites (iii) Symbionts (iv) Commensals (v) Insectivorous plants. HOM E