December 2022

General Principles of Classification Classification is the science that puts organisms into distinct groups to make their study easy and systematic. Modern scientific classification is based on structure and functions. Organisms with similar anatomical and morphological characteristics are placed in one group while those with different structures are grouped separately. Modern studies in genetics and cell biochemistry are used to give additional help in classifying organisms. There are seven major taxonomic groups. The kingdom is the largest group. Others are phylum (division for plants) class, order, family, genus and species, the smallest. Binomial Nomenclature Living organisms are named using Latin or Latinised names. Every organism has two names. This double naming is called binomial nomenclature. This system of naming was devised by Carolus Linnaeus in the 18th Century. The first name is the generic name – the name of the genus. The second name is the name of the species. The generic name starts with a capital letter while that of the species starts with a small letter. The names are written in italics or are underlined in manuscripts. Examples: Bean =Phaseolus vulgaris. Phaseolus is the generic name, vulgaris is specific name. Dog =Canis familiaris. Canis is the generic name ,familiaris the specific name. General Characteristics of Kingdoms Organisms are classified into five kingdoms. Monera, Protoctista, Fungi, Plantae Animalia  Viruses do not fit neatly into any of the above kingdoms. They are simple and not cellular. They are metabolically inactive outside the host cell. Most of them can be crystallised like chemical molecules. Therefore they do not exhibit the characteristics of living organisms. Examples of Organisms in Each Kingdom and Their Economic Importance Kingdom Monera General Characteristics Unicellular and microscopic Some single cells ,others colonial Nuclear material not enclosed within nuclear membrane-prokaryotic Have cell wall but not of cellulose. Have few organelles which are not membrane bound Mitochondria absent Mostly heterotrophic, feeding saprotrophically or parasitically,some are autotrophic. Reproduction mostly asexual through binary fission Most of them are anaerobes but others are aerobes Most move by flagella Examples include  Escherichia coli, Vibrio cholerae and Clostridium tetani. Spherical known as Cocci. Rod shaped – e.g. Clostridium tetani Spiral shaped  e.g. sprilla Coma shaped- Vibrios -e.g., Vibrio cholerae.   Economic importance of bacteria Benefits to man include: They are used in food processing e.g., Lactobacillus used in processing of cheese, yoghurt. Involved in synthesis of vitamin Band K, in humans and breakdown of cellulose in herbivores. Genetic Engineering Bacteria are easily cultured and are being used for making antibiotics, aminoacids and enzymes e.g. amylase, and invertase e.g., Escherichia coli.      Nutrient cycling: Saprophytes They are involved in decomposition of dead organic matter. They are useful in the nitrogen cycle. Nitrogen fixing and nitrifying bacteria. They increase soil fertility. Modem sewage works use bacteria in treatment of sewage. Cleaning oil spills in oceans and lakes. Harmful Effects Bacteria cause disease: To humans (e.g. Cholera). To animals (e.g. Anthrax). Bacteria cause food spoilage. Others cause food poisoning e.g. Salmonella. Denitrifying bacteria reduce soil fertility e.g., Pseudomonas denitrificans. Kingdom Protoctista Examples include ; Algae such as spirogyra, Chlamydomonas, euglena, Sargassum And protozoa such as amoeba, paramecium and Trypanosoma. General Characteristics They are said to be eukaryotic since their nucleus is bound by a membrane Most are mobile, and use flagella, cilia and pseudopodia. Some are sessile. They reproduce mainly asexually, by binary fission, fragmentation and sporulation. Some reproduce sexually by conjugation. Some are heterotrophic e.g. paramecium. Others are autotrophic e.g. spirogyra. Economic importance of protoctista Algae are the primary producers in aquatic food chains. They release a lot of oxygen to the atmosphere. Some cause human diseases like malaria and amoebic dysentry ,sleeping sickness Some are source of food for humans e.g. sargassum is a source of iodine Skeletons of diatoms used in paint making. Spirogyra: They have spiral chloroplast. They are green, thread-like filaments Chlamydomonas: This is a unicellular green algae and has a cup shaped chloroplast. They move towards light using the flagella Cilia assist the organism to move. The shape is due to the presence of a thin flexible pellicle. Kingdom Fungi Multicellular fungi are made of thread-like structures called hyphae (singular hyphae) that form a mycelium. .e.g.Saccharomyces cereviseae(bread yeast). Others include Penicillium, Rhizopus, and edible mushroom Economic Importance of Fungi Beneficial Effects Some fungi are used as food e.g. mushrooms. Some are decomposers which enhance decay to improve soil fertility – recycling of nutrients e.g., toadstools. Some are useful in brewing and bread making e.g., yeast. Yeast is used as food – a rich source of Vitamin B. Some are useful in production of antibiotics e.g., Penicillium griseofulvin. Used in sewage treatment e.g., Fusarium spp. Harmful Effects Some cause food poisoning by producing toxic compounds e.g. Aspergillus flavus which produces aflatoxins. Some cause food spoilage, fabric and wood spoilage through decomposition. Some cause diseases to humans e.g., athlete’s foot and ringworms. Others cause diseases to plants e.g., potato blight (Irish potatoes) rust in tomatoes and smuts in cereals.   Kingdom Plantae General Characteristics They are multicellular and eukaryotic. They are photosynthetic and have a pigment chlorophyll. Their cells have cellulose cell walls. They reproduce sexually, others asexually. Kingdom Plantae has three major divisions: Bryophyta, Pteridophyta Division Bryophyta These include mosses and liverworts. Plant body is not differentiated into root, stem and leaves. They have simple structures which resemble leaves and stems. They have rhizoids for absorbing water and anchoring the plant to substratum. Life cycle consists of two morphologically different plants, the gametophyte and sporophyte. The two alternate. They show alternation of generations. The gamete producing gametophyte is the persistent plant. The sporophyte is attached to the gametophyte and is nutritionally dependent on it. They lack vascular system. Sexual reproduction is dependent on water.   Division Pteridophyta: These include ferns and horsetails.      General Characteristics They have root and shoot system. Leaves are compound known as fronds, they have a vascular system. They show alternation of generations whereby the spore bearing sporophyte is the main plant. Spores are borne in clusters

TOPIC 1 : CLASSIFICATION II – Click to view TOPIC 2 : ECOLOGY – Click to view TOPIC 3 : REPRODUCTION IN PLANTS AND ANIMALS – Click to view TOPIC 4 : GROWTH AND DEVELOPMENT – Click to view

PART I: EXCRETION Excretion is a process by which living organisms separate and eliminate waste products of metabolism from their bodies Metabolic wastes are toxic to cells if allowed to accumulate, and could also alter the normal conditions for cell function, killing the cells Secretion is the release of certain useful substances produced by cells, such as enzymes and hormones Egestion is the removal of indigestible and undigested materials from food vacuoles or alimentary canal   EXCRETION IN PLANTS Plants lack complex excretory organs because: Their wastes accumulate very slowly The main wastes originate from carbohydrate metabolism and are often reused by the plant e.g carbon (IV) oxide, oxygen and water Wastes in form of gases are removed by simple diffusion thro stomata and lenticels Some wastes are stored in non toxic forms in certain tissues or organs which later drop off with age e.g resins, alkaloids Economic Importance of Plant Excretory Products Tannins in barks of Acacia are used in leather tanning Caffeine in coffee berries and tea leaves are used to prepare stimulant drinks Quinine from the bark of cinchona tree and Aloe leaves is an antimalarial agent Papain from raw pawpaw fruit skins is a proteolytic substance used in food industry to soften beef Colchicine is an alkaloid used to induce non-disjunction in genetic breeding expts and to treat cancer Rubber is made from latex of rubber plant, used in making tyres and shoes   Excretion and Homeostasis in Unicellular Organisms Protozoans like Amoeba, Paramecium, remove CO2 and nitrogenous wastes by simple diffusion across their bodies. This is possible because these organisms have large surface area to volume ratio, which allows diffusion rate to be very fast. Wastes diffuse along a diffusion gradient from the cytoplasm across the cell membranes into the surrounding water medium Protozoans remove excess water and dissolved solutes from their bodies by using their contractile vacuole. These substances accumulate in the contractile vacuole, which swells and moves towards the cell membrane then bursts releasing the contents to the outside   EXCRETION IN ANIMALS Animals need an elaborate system of excretion because they have more complex bodies and have numerous cells and thus diffusion alone is not enough to remove wastes Excretory tissues and organs include flame cells in flat worms, nephridia in round worms, malpighian tubules in insects, gills, lungs , liver, kidneys and skin in vertebrates The Mammalian Skin The main functions of the skin are: Defence: protective barrier against entry of microorganisms, mechanical damage, and UV from the sun Regulation of body temperature Excretion: salts, excess water, some urea Reception of stimuli: heat, cold, pain, touch, pressure Vitamin D synthesis on exposure to sunlight Fat storage in adipose tissue   Structure-Function Relationship of the Mammalian Skin Cornified layer: outermost layer of the skin is made of flattened dead cells filled with tough flexible substance called keratin, protects against mechanical damage and entry of bacteria, and reduces loss of water by evaporation Granular layer is the middle layer of skin made of living cells with granules, it gives rise to the cornified layer Malpighian layer is the innermost layer of the skin, made up of actively dividing cells that give rise to new epidermis, the cells have pigment granules called melanin that gives colour to skin, and also absorbs UV rays that are harmful to skin Blood vessels supply nutrients and oxygen to skin tissues and remove waste products, blood also regulates body temperature Lymphatic vessels drain excess tissue fluid Nerve endings detect external stimuli, creating awareness within the body to initiate appropriate responses Sweat glands consist of coiled secretory cells extending into long tubules that open to the surface of the skin as sweat pores. The cells absorb excess water, mineral salts, some urea, lactic acid and CO2 from the surrounding cells and tissues, and secreted to form sweat. This flows through the sweat duct into the skin surface. Sweat glands are involved in temperature regulation thro loss of water by evaporation from skin surface Hair shafts originate from hair follicles located in the Malpighian layer. Erector pili muscles attached to the follicle at one end and to the epidermis on the other end contract and relax to alter the angle btn the hair shaft and the skin. This varies the amount of air trapped btn the hair and the skin, which is important in temperature regulation Sebaceous glands are closely associated with hair follicles; they secrete sebum to keep hair and epidermis flexible and waterproof. Sebum contains antiseptic substances to protect against bacteria. Subcutaneous layer is a layer of fat beneath the dermis; it binds the skin to muscles and other organs deep in the body, stores fats and insulates against heat loss. The Mammalian Kidneys Structure and Function of the Kidneys The functions of kidneys are excretion, osmoregulation, ionic balance and regulation of pH Mammals have 2 kidneys located at the dorsal part of the abdominal cavity in the lumbar region Above each kidney are the adrenal glands that secrete hormones A kidney is convex on one side and concave on the other side. The concave side has a depression called hilum where renal artery enters to supply blood and renal vein leaves to remove blood From the hilum also leaves a large thick walled tube called ureter that links the kidney to the urinary bladder. The ureter transports urine from the kidney to the bladder, which stores urine for a short time. When the bladder is full, sphincter muscles located at the base of the bladder relax and urine is released via the urethra In males the urethra is long and joined to the reproduction system unlike in females LS of kidney show cortex, medulla and pelvis starting from the convex side towards the concave side. In the cortex are glomeruli and Bowman’s capsules, while in the medulla are Loops of Henle and collecting tubules, and in the pelvis are collecting ducts. The basic functional unit of the kidney is called the nephron Fine Structure of the

Definition: process by which food substances are chemically broken down in all living cells to release energy, carbon (IV) oxide and water or alcohol Tissue respiration takes place in mitochondria. These organelles occur in large numbers in cells of organs that require a lot of energy e.g. kidney cells, muscle cells, sperm cells Adaptations: mitochondria have folded inner membrane forming cristae to provide a large S/A for respiratory activities; have a fluid filled cavity called matrix in which respiratory reactions take place; have their own genetic material DNA that enables them to self replicate independently of the cell The Process of Respiration If the energy produced during respiration were to be released at once, the heat would burn the body cells (some energy is always released as heat) To prevent this, energy is released in small quantities and in stages During respiration, energy produced is used to cause reaction between adenosine diphosphate (ADP) and an inorganic phosphate molecule, to form another compound called adenosine triphosphate (ATP)   ADP + PO43- + Energy            =                   ATP   The overall equation for respiration:   C6H12O6 + 6O2      respiratory enzymes            6CO2 + 6H2O + energy (ATP) ATP molecules store energy released in respiration ATP readily breaks down into ADP and phosphate, releasing energy locked in its bonds The first phase of respiration takes place without using oxygen It involves the breakdown of glucose to pyruvic acid it takes place in the cytoplasm of cells glucose is broken down (glycolysis) into a three carbon compound called pyruvic acid Glycolysis produces two molecules of ATP per molecule of glucose. The fate of pyruvic acid depends on whether oxygen is available or not Normally pyruvic acid proceeds onto the second phase of respiration in which it is completely oxidised into carbon (IV) oxide, water and energy (ATP). Oxygen is needed in the second phase It takes place in the matrix of mitochondria It produces 38 molecules of ATP per molecule of glucose. If there is no oxygen, pyruvic acid is converted to lactic acid (in animals) or ethanol (in plants, fungi, and in most bacteria) Lactic acid stores a lot of energy, and when oxygen is available, it is converted back to pyruvic acid, which is then used in the aerobic phase of respiration The process of anaerobic respiration is summarised as: In plants: C6H12O6 2C2H5OH + CO2 + Energy In animals: C6H12O6 2C3H6O3 + Energy Q   Write a simple equation to show how ATP is synthesised from ADP[1] Q  Give two ways in which the properties of ATP make it a suitable source of energy in biological processes [2]   Oxygen Debt It is the oxygen required to get rid of lactic acid that accumulates in the body when the supply of oxygen is less than the demand e.g. during a race Lactic acid is toxic, and causes fatigue and muscle cramps. However, it also locks up a lot of energy in its bonds, which should be availed to the body. Oxygen debt is paid back after the race when the person breaths in quickly and more deeply so as to increase the supply of oxygen During the process of paying back the oxygen debt, lactic acid is converted to pyruvic acid, which is then oxidised to carbon (IV) oxide, water and energy. Lactic acid can also be taken to the liver and converted into glycogen for storage Application of Anaerobic Respiration Production of ethanol, wine, cider, beer and spirits by fermentation of sugars  Biogas production Making of compost manure Production of vinegar, citric acid, oxalic acid and some drugs Respiratory Quotient (RQ) And its Significance RQ is a ratio of the amount of CO2 produced against the amount of O2 consumed during respiration i.e. RQ  =   volume of CO2 produced  / Volume of O2 consumed RQ for carbohydrates = 1.0; fats/lipids = about 0.7; proteins = about 0.9 Significance of RQ values Indicates type of substrate Indicates conditions under which substrates are respired, whether aerobic, anaerobic or both RQ depends on age, state of health and temperature Factors Affecting Rate of Respiration Oxygen concentration Substrate concentration Hormones: adrenaline and thyroxine increase respiration rate Body size/SA:V ratio   Practice Questions  Some sterile seeds were soaked in water for 4 hours before being left in moist air to germinate. The respiratory quotient (RQ) values of these seeds are shown in the table below. Account for the changes in RQ values of the germinating seeds: Immediately after soaking [3] After 12 hours in air [2] After 36 hours in air [3] Q   Desert iguanas are lizards that live in hot, dry conditions. Scientists measured the rate of oxygen consumption of desert iguanas at different body temperatures. Some of their results are shown in the table. Explain how an increase in the iguana’s body temperature affects its oxygen consumption when it is at rest. Q    Name the organism that causes tuberculosis (TB). Explain how TB is transmitted from an infected person to an uninfected person. Q    Explain why carbohydrates release half as much energy per unit mass as fats and oils.[2]

Gaseous Exchange in Plants Gaseous exchange: process by which respiratory gases, O2 and CO2, are passed across the respiratory surface Concentration gradient existing btn the respiratory surface and the surrounding medium facilitates gaseous exchange The mechanism of exchange involves simple diffusion. Gaseous exchange is important because it promotes uptake of O2 for respiration and removal of CO2 as a waste product In plants, the respiratory surface is spongy mesophyll tissue: its cells are loosely packed, with large intercellular air spaces where gases can collect and mix; the cell walls are thin to allow quick diffusion; and are moist to allow gases to dissolve before diffusing; The sites across which gases diffuse into and out of plants are stomata and lenticels.   Q  State two adaptations of spongy mesophyll cells to their function [2]   The Stomata Stomata are NOT cells, but tiny openings found on leaf surface Bordered by bean shaped guard cells. Allow gaseous exchange to take place. Guard cells control the size of stomata by osmotic changes that open more or close the stomatal pores.   The Guard Cells Have thicker inner cell walls and thinner outer cell walls Have a few chloroplasts to allow some photosynthesis to occur Surface view of lower epidermis of leaf of Kalanchoe sp.showing stomata and guard cells  Mechanism of Opening and Closing of Stomata According to photosynthetic theory, guard cells produce sugar through photosynthesis and this causes osmotic pressure of the sap vacuoles to increase. According to the starch-sugar interconversion theory, during daylight photosynthesis takes place in guard cells using CO2. This makes PH in the guard cells to rise, favouring the conversion of starch into glucose. This increases the osmotic pressure of sap vacuoles. As a result, guard cells absorb water by osmosis from adjacent cells and become turgid. Since the inner cell walls are thicker than the outer cell walls, the guard cells bulge outwards making the stomata to open. At night, sugar is converted to starch in guard cells. At night, CO2 accumulates in the guard cells resulting in lowering of PH. This favours the conversion of glucose to starch. Starch is osmotically inactive therefore, the osmotic pressure of guard cells falls The cells lose turgidity due to water loss to adjacent epidermal cells by osmosis Guard cells become flaccid and draw towards one another thereby closing the stomata.   Q Describe the mechanism of stomatal opening [5]   Q Describe the mechanism of stomatal closure [5]   Mechanism of Gaseous exchange in Plants Gaseous exchange takes place in aerial roots, stems and leaves There exists a concentration gradient btn atmospheric air and air inside the roots, stems or leaves O2 diffuses from the atmosphere where its concentration is high into the plant where its concentration is kept low due to respiration CO2 diffuses out of the plant as a metabolic waste product along a concentration gradient Stomata are modified according to habitat. In Xerophytes (plants adapted to living in desert conditions), stomata are small, few in number and are found mainly on the lower leaf surface. In some xerophytes, stomata are found in sunken pits. In others, stomata remain closed at day light, only opening partially at intervals to allow for gaseous exchange and open only at night. This reduces water loss by transpiration In hydrophytes (plants adapted to growing in water or swamps e.g. water lilies), stomata are large, and are more stomata on upper leaf surface than lower leaf surface. This allows the plants to release excess water by transpiration. Hydrophytes also have aerenchyma tissue with large air spaces to store air for gaseous exchange Mesophytes are plants that grow in areas with adequate water supply. They have fairly large number of stomata, of medium size and almost equal in number on both surfaces of leaves. Gaseous exchange also occurs through lenticels. These are openings on stems and roots formed by loosely packed corky cells. Gaseous exchange takes place on the moist surfaces of cells under the lenticels. Gaseous exchange takes place btn the interior of the plant and the outside by diffusion. In halophytes (plants that grow in muddy salty waters e.g. mangroves), gaseous exchange takes place in lenticels found in specialised aerial breathing roots called pneumatophores   The image below shows a transverse section of leaf of a Water Lily (Nymphaea sp.) Plants that are adapted for living in water are known as hydrophytes. The image shows a layer of tissue known as aerenchyma underneath the palisade layer. Aerenchyma contains large air spaces, which gives the leaves buoyancy, allowing them to float on the surface of the water. Stomata occur in the upper leaf epidermis of plants with floating leaves, allowing gas exchange with the air above. The cuticle is usually thin or absent from the leaves of hydrophytes. The high density of water gives support to the submerged leaves and stems, and there is a lack of the supporting tissues found more widely in mesophytes, such as collenchyma or sclerenchyma. Q Explain the mechanism of gaseous exchange in plants [12]   Q State how the following structures are adapted to their function Aerenchyma [1] Lenticels [1] Pneumatophores [2]   Gaseous Exchange in Animals Types of Respiratory Surfaces  Cell membrane e.g. protozoa Gill filaments e.g. fish Tracheoles e.g. insects Alveoli/lungs e.g. mammals, birds, frogs, reptiles Skin e.g. frog, earthworm Buccal cavity e.g. frog Characteristics of Respiratory Surfaces Large S/A Moist surface Rich capillary network Thin membrane Gaseous Exchange in Protozoa e.g. Amoeba Amoeba are single-celled organisms that live under fresh water They have a large SA/V ratio exposed to water Thus, gaseous exchange takes place by diffusion alone very fast across the cell membrane O2 dissolved in water diffuses across the cell membrane into the cytoplasm CO2 and other soluble wastes diffuse out through the membrane into the water along a concentration gradient Gaseous Exchange in Insects Structure and Function of the Tracheal System Spiracles are openings on either side of the abdomen and thorax thro which air enters and leaves the body

Need for Transport carry required substances to body parts remove metabolic wastes from the body Lower organisms and simple multicellular organisms have small bodies that make them have a large surface area to volume ratio. Diffusion alone is enough to transport substances. Higher organisms have large bodies and thus smaller surface area to volume ratio. Hence, tissues and organs are far from the site of supply of materials. Therefore, they require an elaborate transport system. TRANSPORT IN PLANTS Simple plants such as mosses and liverworts transport substances by diffusion, osmosis, and active transport. Higher plants have a specialized transport system known as the vascular bundle. It comprises of xylem (transports water and mineral salts) and phloem (transports dissolved food substances). Root Structure and Function The primary functions of roots are anchorage and absorption. Specialized roots store food and water, and allow gaseous exchange. Root cap: protects the apical meristem. Root hairs: microscopic outgrowths of epidermal cells. Are thin walled to shorten distance for absorption of water and mineral salts. Have an elongated cytoplasm at one side to increase surface area for absorption of water and mineral salts. Piliferous layer: a special epidermis of young roots that gives rise to root hairs. Cortex: loosely packed thin walled cells to allow passage of water molecules to reach the vascular bundles; and to store substances. Endodermis: a single layer of cells surrounding the vascular bundles, characterized by possession of starch grains and a casparian strip, it controls the amount of water and mineral salts entering into the vascular bundles. Vascular bundles: each vascular bundle consists of xylem and phloem. In monocotyledonae, xylem alternate in the arrangement with phloem. In Dicotyledonae, the xylem is star-shaped and the phloem is located at the centre of the star. Epidermis: a single layer of cells covering all other inner tissues Stem Structure and Function The primary functions of stems are support, conduction of water and mineral salts and manufactured food. Other functions of specialized stems include storage of food and water, gaseous exchange and perennation. Epidermis Cortex: simple tissues found in the cortex are: Collenchyma: walls thickened at the corners with cellulose and pectin deposits, and thus it is a strengthening tissue; Parenchyma: irregular cells, thin walled and loosely packed, with intercellular air spaces, store water and food. Some parenchyma cells contain chloroplasts and are called Sclerenchyma: walls thickened by lignin, serve as a strengthening tissue. 3. Pith: central region with parenchyma cells that store water and food substances. 4. Vascular bundles Comparison between the Structure of Monocots and Dicots Absorption of Water and Mineral Salts Absorption of Water Water is drawn into root hair cells by osmosis Cell sap of root hairs contains dissolved substances that make its concentration to be greater than that of the soil solution Therefore, there exists a concentration gradient between cell sap and soil water This exerts a higher osmotic pressure thus drawing water molecules from soil across the cell wall and cell membrane of root hair cells The osmotic forces exerted by the cells overcome the water retaining powers of the soil thus water enters the root hair cells As more water is drawn into root hair cells, it dilutes the cell sap making it less concentrated than that in the adjacent cortex cell of the root Due to osmotic gradient, water moves from the adjacent cells to the next by osmosis Similarly, water passes through the successive cortex cells until it enters the xylem vessels located in the center of the root The xylem vessels then conduct the water up into the xylem vessels of the stem and into the leaves Uptake of Mineral Salts Soil water contains dissolved mineral salts, which plants require for their growth and proper functioning Generally, the concentration of the cell sap in the root hairs is greater than that in the soil The mineral salts therefore enter the root hairs against the concentration gradient This process requires the use of energy and is referred to as active transport Active transport is believed to involve substances known as carriers These carriers combine with the mineral ions and then carry them across the plasma membrane into the cell Thus, the carriers move back and forth carrying the salt ions from the soil water to the root hair cells After absorption, the mineral salts move through the root cells into the xylem vessels of the vascular tissue in the centre of the root Then the salts and water are carried up the stem into the leaves by a combination of osmosis, diffusion, root pressure, transpiration pull, cohesive forces and capillary attraction Forces involved in Transportation of Water and Mineral Salts Transpiration pull A suction force pulls a stream of water from the xylem vessels in the stem and roots. It develops when water vaporizes from the spongy mesophyll cells, increasing the concentration of their cell sap, which in turn increases the osmotic pressure and causes water to flow from surrounding cells and xylem vessels. Transpiration pull creates a continuous stream of water flowing from the roots, up the stem to the evaporating surface referred to as transpiration stream  Distinguish between the terms transpiration pull and transpiration stream [1]How does transpiration pull arise? [3] Cohesion and Adhesion forces Cohesion force: forces that keep water molecules together Adhesive force: attractive force between water molecules and the walls of xylem vessels Capillarity Ability of a solution to rise up in a tube with a very small diameter because of surface tension Water rises up by capillary action in xylem vessels because they are very narrow and there is a high attractive force between the water molecules and the cell walls Root pressure A force in the roots that pushes water up the stem Root pressure is caused by active pumping of water across the endodermis to the xylem vessels because the casparian strip present in endodermis is almost impermeable to water Energy is required in this process   TRANSPIRATION Dfn: Process by which plants lose water in the

TOPIC 1 : TRANSPORT IN PLANTS AND ANIMALS – Click to view TOPIC 2 : GASEOUS EXCHANGE – Click to view TOPIC 3 : RESPIRATION – Click to view TOPIC 4 : EXCRETION AND HOMOESTASIS – Click to view

Introduction Nutrition refers to the process by which living organisms obtain and assimilate (utilize) nutrients. It is one of the fundamental characteristics of living things. The nutrients obtained are useful to the living organisms in many ways: The nutrients are required for growth and development of the living organisms. The nutrients are required for energy provision as they are broken down to release energy. They nutrients are also required for repair of worn out tissues Nutrients are required for synthesis of very vital macromolecules in the body such as hormones and enzymes. Modes of nutrition There are two main nutrition modes: Autotrophism: mode of nutrition through which living organisms manufacture their own food from simple inorganic substances in the environment such as carbon (IV) oxide, water and mineral ions. Organisms that make their own food through this mode are autotrophs. Heterotrophism: mode of nutrition in which living organisms depend on already manufactured food materials from other living organisms. Heterotrophs are the organisms that feed on already manufactured food materials. AUTOTROPHISM In this mode of nutrition, organisms manufacture their own food from readily available materials in the environment. These organisms use energy to combine carbon (IV) oxide, water and mineral salts in complex reactions to manufacture food substances. Depending on the source of energy used to manufacture the food, there are two types of autotrophism: Chemosynthesis This is the process whereby some organisms utilize energy derived from chemical reactions in their bodies to manufacture food from simple substances in the environment. This nutrition mode is common in non green plants and some bacteria which lack the sun trapping chlorophyll molecule. Photosynthesis This is the process by which organisms make their own food from simple substances in the environment such as carbon (IV) oxide and water using sunlight energy. Such organisms often have chlorophyll which traps the required sunlight energy. This mode of nutrition is common in members of the kingdom Plantae. Some protoctists and bacteria are also photosynthetic. Importance of Photosytnthesis Photosynthesis helps in regulation of carbon (IV) oxide and oxygen gases in the environment. Photosynthesis enables autotrophs make their own food, thus, meet their nutritional requirements. Photosynthesis converts sunlight energy into a form (chemical energy) that can be utilized by other organisms that are unable to manufacture their own food. Photosynthesis largely occurs in the leaf. To understand the process of photosynthesis, it is important to understand the leaf structure. External leaf structure Externally, the leaf has a petiole through which it attaches to the leaf branch or stem, lamina- the broad flat surface, margin- the outline and the leaf apex. The leaf margin can be smooth, dentate, serrated or entire. The size of a leaf depends on its environment. Plants in arid areas have small sized leaves with some leaves reduced to needle like shape. This helps reduce the rate of water loss in such plants. However, the plants in areas of water abundance have broad leaves to enable them lose the excess water. Cuticle This is the outermost layer of the leaf. It is a thin non-cellular, waxy, transparent and waterproof layers that coats the upper and lower leaf surfaces. Functions of the cuticle Being waterproof, it minimizes water loss from the leaf cells to the environment through transpiration and evaporation. It protects the inner leaf tissues from mechanical damage. It prevents entry of pathogenic microorganisms into the leaf.   Epidermis This is the outermost one cell thick layer covering upper and lower leaf surfaces. Its cells are flattened and lack chloroplasts. Functions of the epidermis: It protects the leaf from mechanical damage. It also protects the leaf from entry of disease-causing microorganisms. It secretes the cuticle. There are many small pores on the epidermis known as stomata (singular-stoma) through which exchange of materials occur. The opening and closing of the stomata is controlled by the guard cells. Each stoma is controlled by two guard cells. The guard cells have chloroplasts and are bean shaped. They have thicker inner cell wall and thinner outer cell wall. Adaptations of the guard cells They have differentially thicker walls to enable them bulge as they draw water through osmosis from the neighboring cells making them to open the stomata. They contain chloroplasts that manufacture sugars which increase osmotic pressure of the guard cells. As they draw water through osmosis, they bulge making the stomata to open. Palisade mesophyll This is the chief photosynthetic tissue in plants. Its cells are regular in shape. Its cells contain numerous chloroplasts for photosynthesis. Their close packing and location just below the epidermis enables them to trap maximum sunlight for photosynthesis. Location of palisade layer on the upper surface explains why upper leaf surfaces are greener than the lower surfaces. Spongy mesophyll layer This layer contains loosely arranged irregular cells. This leaves large airspaces between the cells which permits free circulation of gases carbon (IV) oxide and oxygen into the photosynthetic cells. Spongy mesophyll cells contain fewer chloroplasts compared to palisade cells. Vascular bundle/tissue This is found in the midrib and leaf veins. Vascular bundle is made of phloem and xylem tissues. Xylem tissues conduct water and some dissolved mineral salts from the roots to other plant parts while phloem translocates manufactured food materials from photosynthetic areas to other plant parts. Chloroplast This is the organelle in which photosynthesis takes place. It is an oval shaped double membrane bound organelle. Internally, it is made up of membranes called lamellae suspended in a fluid filled matrix called stroma. Lamellae forms stacks at intervals called grana (singular-granum). Chlorophyll molecules are contained in the grana. Within the stroma, fat droplets, lipid droplets and starch grains are found. The strona contains enzymes and forms the site where light independent reactions take place. Adaptations of the leaf to photosynthesis The leaf has a flat snd broad lamina to increase surface area for trapping sunlight energy and for gaseous exchange. The leaf has numerous stomata through which photosynthetic gases diffuse. The leaf is thinto reduce the distance through which carbon (IV)

TUESDAY: 6 December 2022. Morning paper. Time Allowed: 2 hours. Answer ALL questions by indicating the letter (A, B, C or D) that represents the correct answer. This paper is made up of fifty (50) Multiple Choice Questions. Each question is allocated two (2) marks. 1. Which of the following is the MOST important DNS server resource? A. Network connection B. Disk storage C. Mouse D. Keyboard 2. Server maintenance entails a software updated and running so that a computer network can operate smoothly and avoid downtime or loss of data. Which of the following events is the MOST catastrophic? A. Losing a backup B. Crashing of server software C. Losing a server disk when there is no backup D. A disk failing 3. Which one of the following statement BEST illustrates preventive maintenance? A. Changing an old system B. Preparing against millennium bug C. Updating a software D. Cleaning a computer system 4. Network Operating system is primarily designed to support workstations, personal computers and older terminals on a local area network. Which of the following is an example of a network operating system? A. Ubuntu B. Mint C. Windows 7 D. Windows server 2016 5. A computer device that can prevent tampering access of server at the boot time is known as? A. RAM B. Cache C. BIOS D. North gate 6. Which of the following is NOT commonly monitored in a server? A. Availability B. Responsiveness C. Capacity D. Clock speed 7. The disk interface is the connection of hard disk and host system. Which of the following is the BEST for a server hard disk interface? A. USB B. SATA C. IDE D. EIDE 8. Which of the following is a daily server maintenance routine? A. Restarting B. Cleaning C. Updating systems D. Lubrication 9. Which of the following commands would halt a windows server system in a network? A. Shutdown /0 B. Restart /R C. Init 0 D. Init halt 10. Which of the following is a server performance metric? A. Network speed B. Hard disk speed C. Availability D. Administrator qualification 11. Which of the following is TRUE about server logs? A. Records only suspicious activities B. They are text files C. Servers are always creating logs D. Readily accessible by all users 12. A server administration entails configuration and maintenance of servers to make sure IT infrastructure runs smoothly. Which of the following identifies a BEST practice about server administration? A. Done only by ICT manager B. Should be outsourced C. Should be done by any user with the right privileges D. Administrator should log in with the privileged account only when necessary 13. Which of the following statement BEST illustrates running a server in safe mode? A. protects the system from viruses. B. protects the system from data loss. C. loads a minimum number of drivers. D. prevents unauthorized access. 14. Identify among the following, an appropriate reason for sharing memory in a server. A. To secure data B. Avoid server overheating C. To perform high speed communication among processes D. To speed data processing 15. Which of the following would be the appropriate action to be undertaken when server CPU utilization is maximum or near maximum? A. Server well utilised B. Need to add another server C. Poor performance D. It needs tuning 16. Which of the following statement BEST illustrates the term server farm? A. A group of work stations B. The fastest server C. Server room D. A collection of organisation computer servers for an organization 17. Server maintenance is process of keeping a server software updated and running so that a computer network can operate smoothly and avoid downtime or loss of data. Server maintenance consist of the following actions EXCEPT? A. Purchase of components B. Replace of component C. Repair of component D. Service of component 18. What is the appropriate term given from the point of time the machine fails to when it is repaired? A. Break Down time B. Maintenance time C. Down time D. Uptime 19. Which of the following decreases with the increase in maintenance efforts? A. Down time B. Cost maintenance C. Overhead Cost D. Labour 20. What is the CORRECT system maintenance procedure? A. Problem – Cause – Diagnosis – Rectification B. Problem– Diagnosis – Cause – Rectification C. Problem – Measure – Diagnosis – Rectification D. Problem– Diagnosis – Measure – Rectification 21. A multinational corporation backup plan calls for a full back up every Sunday. Every other day of the week, system administrator needs to back up only the changes since the last full backup. Which backup type should be used on a Tuesday? A. Daily B. Normal C. Copy D. Differential 22. Which of the following network command utility network configuration details of the server? A. Ip B. Chk C. Ipconfig D. Syscheck 23. Which of the following should be used to protect a server in case of a blackout? A. Uninterruptible Power Supply. B. Power Supply Unit. C. Hot-swappable power supply. D. Line conditioner. 24. When preparing server for use, which of the following is NOT a system Requirement? A. Crimping tool B. Processor C. Random Access Memory(RAM) D. Disk space 25. Which of the following causes a server NOT to reply to echo request from a client? A. If virtual box is not well configured B. If DHCP is blocking the traffic C. If the command is wrong D. When a firewall is blocking the traffic 26. Which one of the following is a lightweight command used in poweshell environment? A. Cmdlets B. Parser C. ISE D. Toggle breakpoint 27. Which of the following tools can be used by an administrator to retrieve detailed information about a significant occurrence from server? A. Event Viewer B. System Information C. System Monitor D. Resource Monitor 28. Group Policy is a hierarchical infrastructure that allows a network administrator in charge of Microsoft’s Active Directory to implement specific configurations for users and computers. By default, group policies are first

MONDAY: 5 December 2022. Afternoon Paper. Time Allowed: 3 hours. Answer ALL questions. This paper has two sections. SECTION I has twenty (20) short response questions. Each question is allocated two (2) marks. SECTION II has three (3) practical questions of sixty (60) marks. Marks allocated to each question are shown at the end of the question. Required Resources: Windows server 2016/2019/2022 image Oracle Virtual box Linux/Windows computer SECTION I (40 MARKS) 1. A logical grouping of related network access technologies is referred to as________________. (2 marks) 2. State the component that could be put in place to deploy network virtualisation and centrally manage Data centre Firewall policies. (2 marks) 3. The ______________ entails users, computers, other groups and other Active Directory objects where administrators can manage it as a single object to simplify network maintenance and administration. (2 marks) 4. A mechanism that allows users to group two or more physical Network Interface card (NICs) into a single logical network device is known as_____________. (2 marks) 5. You have been tasked to create a subnet from private IP address of 172.16.10.0/24 to a server that supports four hosts. The solution must minimise the number of addresses available to the subnet. Demonstrate the subnet that should be used. (2 marks) 6. State the Windows Server feature that enables you to group multiple servers together into a fault tolerant cluster to increase availability and scalability of applications and services such as Scale-Out File Server, Hyper-V and Microsoft SQL Server. (2 marks) 7. The ___________ forms part of computer’s DNS name that follows the hostname element such as skypc to make it skypc.accounting.kasneb.or.ke. (2 marks) 8. The ___________ feature in window server operating system allows users across organisational boundaries to access applications using a single set of login credential. (2 marks) 9. The process that eliminates excessive copies of data and significantly decreases storage capacity requirements is referred to as ______________. (2 marks) 10. State the feature in PowerShell used by administrators to automate the configuration of Windows and Linux operating systems. (2 marks) 11. The ____________ command utility helps administrators to diagnose Active Directory replication problems between domain controllers running Microsoft Windows operating systems? (2 marks) 12. A segmented piece of a larger network design strategy where all subnet masks can have varying sizes is known as ______________. (2 marks) 13. An IP address is a unique address that identifies a device on the internet or a local network where servers and hosts are located. Determine the usable host addresses that are available in 192.168.10.50/30 network. (2 marks) 14. An upcoming multinational pharmaceutical company has been issued with 2001:DB8: ACAD: :/48 by the service provider. Compute the bits available given the prefix to create 64 subnetworks for the servers located in different site locations if interface ID bits are borrowed. (2 marks) 15. The term that describes the type of backup that only copies data that has been changed or created since the previous backup activity was conducted is known as ____________. (2 marks) 16. The process of selecting, preparing, extracting and transforming data before permanently transferring it from one computer storage system to another is referred to as __________. (2 marks) 17. State the name given to the process of gaining visibility into the activity on your servers whether physical or virtual. 18. State the name of the system or router that provides a gateway between users and the internet. (2 marks) 19. The administration of network services such as DNS and DHCP that assign and resolve IP addresses to machines in a TCP/IP network is known as ______________. (2 marks) 20. State the server role that refers to a logical grouping of related network access technologies such Routing and Web application proxy. (2 marks) SECTION II (60 MARKS) Required Resources: Windows Server 2016/2019/2022 image Oracle Virtual box Linus/Windows computer Install Oracle Virtual box and Windows server image to your computer and answer the following questions: 21. Create a word processing document named “Domain” and use the word processor document to save your answers to questions 1 to 3: 1. With the use of active directory domain, capture a screenshot displaying the following: Domain directory named songambele.com. (4 marks) Ethernet properties of a second valid unicast address of 172.16.0.0/24 network. (4 marks) 2. Using an appropriate command utility, display the system information of the server you are using. (6 marks) 3. Configure the switch teaming mode to “switch independent” and the load belonging mode to be dynamic. Capture a screenshot to demonstrate how you have performed the above task. (6 marks) Upload domain document (Total: 20 Marks) 22. Create a word processing document named “DHCP” and use the word processor document to save your answers to questions 1 to 2. 1. Configure DHCP server role using role -based installation. Capture screenshot of your configuration settings. (4 marks) Capture a screenshot displaying DHCP server manager console. (4 marks) 2. Configure a scope using appropriate name of Network address 10.0.0.0/24 in your DHCP server console. Capture a screenshot showing an address pool of 10.0.0.1 to 10.0.0.254. (3 marks) Capture a screenshot of the excluded address from 10.0.0.1 to 10.0.0.4 with a delay of 10 milliseconds. (3 marks) Capture a screenshot of lease duration of IP usage to be 1 day 12 hours and 30 minutes. (3 marks) Capture a screenshot that specify 10.0.0.1 as the IP address for a router to be used by clients. (3 marks) Upload DHCP document. (Total: 20 marks) 23. Create a word processing document named “Address” and use the word processor document to save your answers to question 1. 1. A reservation ensures DHCP client is always assigned the same IP address. Configure a reserved client named “printer” for both DHCP and BOOTP using 10.0.0.9 IP address. (6 marks) 2. Capture a screenshot of the available scope options. (3 marks) 3. Using appropriate command, display the Ethernet adapter settings. (3 marks) 4. Using appropriate command utility, query the DNS record of www.altoromutual.com as the remote site.

MONDAY: 5 December 2022. Morning Paper. Time Allowed: 3 hours. Answer ALL questions. This paper has two sections. SECTION I has twenty (20) short response questions. Each question is allocated two (2) marks. SECTION II has three (3) practical questions of sixty (60) marks. Marks allocated to each question are shown at the end of the question. Required Resources: Computer Simulator such as GNS3/packet tracer SECTION I (40 MARKS) 1. IP Routing is a process that sends packets from a host on one network to another host on a different remote network. Which command utility can be used on a host to display IP Routing table? (2 marks) 2. Ayden a newly hired system administrator wanted to modify the name of a router in the network. Which network protocol can he use to securely access the router remotely over the network? (2 marks) 3. The TCP/IP Stack works just like the OSI model by establishing a set of rules and standards for communication in and between the different layers. Which component of the computer is believed to be functioning well when a user is able to ping the ip address of the localhost successfully? (2 marks) 4. Network statistics (netstat) command is a networking tool used for troubleshooting and configuration that can also serve as a monitoring tool for connections over the network. Which command option can be used to list TCP connections only? (2 marks) 5. Which command utility is used to test the ability of the source computer to reach a specified destination computer until stopped? (2 marks) 6. A command utility that is mostly in Linux operating system used to trace path from source to destination in an internetwork is called? (2 marks) 7. As a safety measure a network administrator has been mandated to ensure the guest computers for an upcoming conference cannot ping each other. Which settings can be used to accomplish this task? (2 marks) 8. Debug ip icmp command is used to display information about Internal Control Message Protocol (ICMP) transactions and allows you to monitor the ICMP messages sent and received by your router. What is the name of the command that can be used to stop the debug command on a router? (2 marks) 9. A user tried to access the internet using a computer and received an IP Address of 169.254.142.5. What is the name of the application layer protocol that failed? (2 marks) 10. Network latency is a term used to describe delays in communication over a network. What mechanism can be implemented in a small network to help minimize network latency for real-time streaming applications? (2 marks) 11. The command tool that is used to provide information about network latency and network loss at intermediate hops between a source and destination is known as? (2 marks) 12. ARP command is a TCP/IP utility used for viewing and modifying the local Address Resolution Protocol (ARP) cache that contains resolved MAC addresses of Internet Protocol (IP) hosts on the network. Which command utility is used to display computer’s ARP table? (2 marks) 13. Ms-Dos command utility that enables a user to look up the IP address of a domain or host on a Network is referred to as? (2 marks) 14. Topology defines the structure of the network of the way components are interconnected to each other. Which element of scaling a network involves identifying the physical and logical topologies? (2 marks) 15. Which layer of the Open system Interconnection (OSI) model should be considered when troubleshooting mode of communication between two routers that are geographically far apart? (2 marks) 16. A user reported that she is unable to reach the website when typing http://www.kasneb.or.ke in a web browser, but can reach the same site by typing http://209.168.4.80. What could be the probable cause of the issue? (2 marks) 17. IP stack in network setup is considered to be initialized when an individual test connectivity to which type of IP address? (2 marks) 18. Which element of network design consideration will be best suited to a large corporation as compared to small medium enterprise type of business? (2 marks) 19. The performance metrics obtained by measuring the network for a particular time period is called? (2 marks) 20. The Internet record listing command that contains the details of who owns a domain name and how to get in touch with them is referred to as? (2 marks) SECTION II (60 MARKS) 21. Commands can be very useful when documenting a network especially when a Network administrator wants to gather information directly from routers and switches. Below is a list of commands issued in an intermediary device, that is a router for data collection. Give the description of the commands listed: 22. Examine the flowchart below and answer the questions based on the following scenarios: Describe what is MOST likely to happen if the destination address in the packet: Does not match entry in the routing table. (5 marks) Matches a single entry in the routing table. (5 marks) Matches more than entry in the routing table and the routing entries have the same prefix length. (5 marks) Matches more than entry in the routing table and the routing entries have different prefix length. (5 marks) (Total: 20 marks) Create a word processing document named “Topology” and use it to save answers to questions 1 to 4 23. Using appropriate simulator, design the topology as shown below. Required: 1. Capture a screenshot displaying the Internet Protocol address of the intermediary devices. (6 marks) 2. Capture a screenshot displaying connectivity between: PC-X and PC-Y. (2 marks) RI and PC-X. (2 marks) SW1 and PC-Y. (2 marks) 3. Capture a screenshot showing traceability from PC-X to RI. (4 marks) 4. Capture a screenshot from RI displaying layer I and II of the OSI Model. (4 marks) (Total: 20 marks) Upload “Topology” document.

TUESDAY: 6 December 2022. Afternoon Paper. Time Allowed: 2 hours. Answer ALL questions by indicating the letter (A, B, C or D) that represents the correct answer. This paper is made up of fifty (50) Multiple Choice Questions. Each question is allocated two (2) marks. 1. Which of the following is a tool that inspects an application code to estimate the way it behaves while running? A. Dynamic analysis B. Static analysis C. Scanning analysis D. Maintenance analysis 2. During network security penetration testing, the results of the penetration test are compiled into a report detailing all of the following EXCEPT: A. None sensitive data that was accessed B. Specific vulnerabilities that were exploited C. Sensitive data that was accessed D. The amount of time the pen tester was able to remain in the system undetected 3. The motivation of internal threat that involves stealing information for another organisation is referred to as? A. Fraud B. Sabotage C. Espionage D. Revenge 4. The physical control that requires employees to tap their ID pass on a reader that will unlock the gate and allow them to pass through is referred to as? A. Turnstiles B. Electronic Doors C. Mantraps D. Security Guards 5. Employees in an organisation can contribute to data breaches in the following ways EXCEPT: A. Using unauthorised devices B. Improper access control C. Using unauthorised software D. Spoofing or sniffing 6. Which of the following is NOT a penetration testing method? A. External testing B. Triple blind testing C. Internal testing D. Blind testing 7. The type of cyber security attack where attackers access someone else’s computer for mining cryptocurrency is referred to as? A. Cryptojacking B. Cryptocurrency C. Insider threat D. Man in the middle attack 8. Which of the following is NOT a precautionary measure to be undertaken to prevent cyber-attacks? A. Frequent changing of passwords B. Regularly updating operating systems and applications C. Not opening emails from unknown senders D. Using single factor authentication 9. Which of the following is a BEST practice to protect against an insider attack? A. Protect non-critical assets B. Enforce policies C. Increase volatility D. Promote non-culture changes 10. An attack on confidentiality where the attacker gains access to an asset is referred to as? A. Modification B. Interception C. Interruption D. Fabrication 11. Which of the following is a type of passive attack? A. Denial of service B. Release of message contents C. Spoofing D. Sniffing 12. A cyber security attack that involves the creation of a false stream or modification of the data stream is referred to as? A. Active attack B. Passive attack C. Cryptographic attack D. Encryption 13. The type of cryptography that involves a pair of keys known as a public key and a private key which are associated with an entity that needs to authenticate its identity electronically is referred to as? A. Private key cryptography B. Universal key cryptography C. Public key cryptography D. Decryption key cryptography 14. The DES (Data Encryption Standard) cipher follows the fiestal structure. Which of the following properties are NOT shown by the fiestal structure? A. The plain text is converted into a matrix form first B. The input text is divided into two parts: one being left half and another one being right half. C. The input text is divided into two parts: one being left half and another one being right half. D. Swapping of the left and right halves are performed after each round. 15. The kind of symmetrical encryption algorithm where a set of bits is encoded with a specific secret key in electronic data blocks is referred to as? A. Stream algorithm B. Block algorithm C. Symmetrical algorithm D. Fixed algorithm 16. All of the following should be included in a network testing plan EXCEPT? A. Definition of test objectives B. Testing approach. C. Testing tools. D. Testing personnel 17. The type of network testing that describes how you can test that every possible client platform can operate with every possible server platform is referred to as? A. Functional testing B. Configuration testing C. Concurrency testing D. Peak load testing 18. Which of the following is the fourth stage to be executed when creating a network test plan? A. Analyze the product. B. Design the Test Strategy. C. Define Test Criteria. D. Resource Planning. 19. Which of the following is NOT a cyber essential control in network security? A. Patch management B. Firewall C. Digital certificate D. Access control 20. For a password based authentication, an organisation should: A. Protect against brute force password guessing B. Set a minimum password length of at least eight characters C. Change passwords promptly when the user knows or suspects they have been compromised D. Implement digital certificates to protect passwords 21. A type of attack where a perpetrator first investigates the intended victim to gather necessary background information such as potential points of entry and weak security protocols is referred to as? A. Man in the middle attack B. Social engineering C. Spoofing D. Sniffing 22. A cyber security methodology that combines best practices and technology to prevent the exposure of sensitive information outside of an organisation is referred to as? A. Email security B. Sandboxing C. Intrusion prevention system D. Data loss prevention 23. Robust network security will protect against all of the following EXCEPT A. Worms B. Viruses C. Intrusion D. Spyware 24. A social engineering attack technique where the attacker uses a false promise to lure users into a trap that steals their personal information is referred to as? A. Baiting B. Scareware C. Pretexting D. Phishing 25. Which of the following is NOT a network security policy objective? A. To determines policy enforcement B. To lay out the architecture of the organisation’s network security environment C. To keep malicious users out D. To enable users to access data 26. The activity of verifying the identity of a user is referred to as? A. Identification B. Authentication C. Verification D. Validation 27.