THE UNKNOWN SOLUTION TEAM

(4ai) Air is a mixture of gases, primarily composed of nitrogen, oxygen, carbon dioxide, and trace amounts of other gases. (4aii) Nitrogen (4aiii) A noble gas is an element from Group 18 of the periodic table, characterized by its stable and inert nature. (4aiv) (i) They are chemically inert (ii) They have a full outer electron shell (iii ) They exist as colorless, odorless gases at room temperature. (4bi) (PICK ANY TWO) (i) Calcium chloride (ii) Sodium sulfate (iii) Potassium hydroxide (iv) Anhydrous calcium sulfate (4bii) N2 + 3H2 ----> 2NH3 (4biii) It is often done through upward displacement of air or downward delivery into a container. (4biv) Differences in the method of collection of gases depend on factors such as the gas's density, solubility, and reactivity with atmospheric components. (4ei) -Haematite undergoes reduction -Coke acts as a reducing agent and provides heat. -Limestone undergoes decomposition to form calcium oxide. (4eii) Cast iron is brittle and contains a higher percentage of carbon compared to wrought iron, which is malleable and has a lower carbon content. (4eiii) Conditions favoring the conversion of sulfur (IV) oxide to sulfur (VI) oxide include low temperature, high pressure, and the presence of a catalyst. (4di) Both diamond and graphite have high melting points due to the strong covalent bonds between carbon atoms in their structures. In diamond, each carbon atom forms four strong covalent bonds in a tetrahedral structure, while in graphite, carbon atoms are arranged in layers held together by weak van der Waals forces.

*WAEC GCE CHEMISTRY* *NUMBER FIVE* (5a) Soap is manufactured through a process called saponification. In this process, pellets of sodium hydroxide (NaOH) and vegetable oil are used as the main ingredients. First, the vegetable oil is heated, and then the heated vegetable oil is mixed with sodium hydroxide pellets. This mixture is stirred continuously until a thick, creamy consistency is achieved. This mixture is then left to cool and solidify into soap bars. The sodium hydroxide reacts with the fatty acids present in the vegetable oil, resulting in the formation of soap molecules. (5bi) The industrial preparation of oxygen from air involves a process called fractional distillation. Air is first compressed and cooled, causing it to liquefy. This liquefied air is then subjected to fractional distillation, a process that separates the different components of air based on their boiling points. Oxygen, which has a lower boiling point than nitrogen, is separated and collected as a pure gas. (5bii) (i) oxygen: Oxygen supports combustion and is necessary for a flame to burn. (ii) Hydrogen: hydrogen is highly flammable and can readily ignite. (5ci) (i) Calcium hydroxide: It helps to neutralize any acidic components and improve the overall quality of the water. (ii) Calcium: is an essential nutrient for human health and is important for the development and maintenance of strong bones and teeth. (5cii) (i) Natural sources (ii) Fossil fuel extraction and combustion (5ciii) When sulfur reacts with iron, iron sulfide (FeS) is formed. This reaction can be represented by the equation: Fe + S -> FeS (5di) The term hardness of water refers to the concentrationof dissolved minerals, particularly calcium and magnesium ions. Hard water can cause build-up and scaling in pipes and appliances, reduce the effectiveness of soaps and detergents, and can also affect the taste and odor of water. (5dii) 2H2SO4 + 2NaCl → 2HCl + Na2SO4 (5diii) Fe2O3 + 3CO → 2Fe + 3CO2

(1d) (i) Ensure that both copper(II) oxide and dilute trioxonitrate(V) acid used in the reaction are of high purity. (ii) Ensure that the beakers and stirring rods used are clean and dry.

*NECO GCE BIOLOGY* (5ai) (PICK ANY FOUR) (i) Water (ii) Oxygen (iii) Temperature (iv) Light m (v) Soil or substrate (vi) Time (5aii) In Tabular form -Hormonal Coordination: (PICK ANY THERE) (i) Hormones are chemical messengers secreted by endocrine glands and released into the bloodstream. (ii) Hormonal responses are slower and more gradual compared to nervous responses. (iii) Hormonal responses are often long-lasting. (iv) Hormonal communication is based on the release and diffusion of hormones throughout the body. (v) Hormones act on specific target cells or organs that have appropriate receptors. (vi) Hormonal coordination controls processes such as growth, development, reproduction, and metabolism. -Nervous Coordination: (PICK ANY THREE) (i) Nerves are specialized cells that transmit electrical impulses rapidly. (ii) Nervous responses are rapid and immediate. (iii) Nervous responses are often short-lived. (iv) Nervous coordination is based on the transmission of electrical signals along nerve cells. (v) Nerves directly connect specific cells, tissues, and organs. (vi) Nervous coordination controls processes such as movement, sensation, and reflex actions. *(5bi)* The following processes are involved during exhalation in human: (i) The thoracic cavity first decreases (ii) The diaphragm relaxes and assumes its dome-shape (iii) The intercostal muscles relax (iv) The sternum now moves inwards (v) The ribs are moved downwards and inwards (5bii) (i)They have fleshy, water-storing tissues or specialized structures to reduce water loss. (ii) They have smaller or modified leaves, such as spines or scales, to minimize water loss through transpiration. (iii) They have deep and extensive root systems to reach underground water sources. (iv) They have a waxy cuticle or hairy surfaces on their leaves to reduce water loss through evaporation. (v) Some employ Crassulacean acid metabolism (CAM) photosynthesis, a specialized pathway that allows them to open their stomata at night, reducing water loss during the day.

*USE THIS 5Bi only* 🙏🙏🙏

(5bi) The following processes are involved during exhalation in human: (i) The thoracic cavity first decreases (ii) The diaphragm relaxes and assumes its dome-shape (iii) The intercostal muscles relax (iv) The sternum now moves inwards (v) The ribs are moved downwards and inwards

*am correcting 5bi hold for it ....*

*NECO GCE BIOLOGY* (5ai) (PICK ANY FOUR) (i) Water (ii) Oxygen (iii) Temperature (iv) Light m (v) Soil or substrate (vi) Time (5aii) In Tabular form -Hormonal Coordination: (PICK ANY THERE) (i) Hormones are chemical messengers secreted by endocrine glands and released into the bloodstream. (ii) Hormonal responses are slower and more gradual compared to nervous responses. (iii) Hormonal responses are often long-lasting. (iv) Hormonal communication is based on the release and diffusion of hormones throughout the body. (v) Hormones act on specific target cells or organs that have appropriate receptors. (vi) Hormonal coordination controls processes such as growth, development, reproduction, and metabolism. -Nervous Coordination: (PICK ANY THREE) (i) Nerves are specialized cells that transmit electrical impulses rapidly. (ii) Nervous responses are rapid and immediate. (iii) Nervous responses are often short-lived. (iv) Nervous coordination is based on the transmission of electrical signals along nerve cells. (v) Nerves directly connect specific cells, tissues, and organs. (vi) Nervous coordination controls processes such as movement, sensation, and reflex actions. (5bi) The following processes are involved during inspiration in man: (i) The thoracic cavity first increases in volume. (ii) The diaphragm contracts and becomes flattened. (iii) The intercostal muscles contract. (iv) The sternum is moved forward. (v)The ribs are moved upwards and outwards. (vi) There is an increase in the volume and a decrease or a fall in the pressure of thoracic cavity. (vii) Consequently, air from outside is drawn into the lungs or alveoli through the nose, trachea, bronchus and bronchioles leading to an increase in the size of the lungs. (5bii) (i)They have fleshy, water-storing tissues or specialized structures to reduce water loss. (ii) They have smaller or modified leaves, such as spines or scales, to minimize water loss through transpiration. (iii) They have deep and extensive root systems to reach underground water sources. (iv) They have a waxy cuticle or hairy surfaces on their leaves to reduce water loss through evaporation. (v) Some employ Crassulacean acid metabolism (CAM) photosynthesis, a specialized pathway that allows them to open their stomata at night, reducing water loss during the day.

BIOLOGY OBJ 1-10: CBDEDACCBD 11-20: AAEBCDDECB 21-30: BDCACBEAEE 31-40: DDCDEDCAAB 41-50: ADEEDADABE 51-60: EAAEACADAB

*NECO GCE BIOLOGY* (2ai) The process involves the activation of dormant tissues within the seed, leading to the development of a young plant includes: (i) Imbibition: The seed absorbs water from the soil, causing it to swell and activate biochemical processes within the seed. (ii) Activation of Enzymes: The imbibed water activates enzymes within the seed, which initiate the metabolic processes necessary for germination. (iii) Mobilization of Stored Energy: The stored energy reserves, such as starch and proteins, within the seed are broken down into simple sugars to provide energy for the growing embryo. (iv) Growth of the Embryo: The embryo grows, and the radicle (primary root) emerges from the seed, followed by the emergence of the shoot, which develops into the stem and leaves. (v) Photosynthesis: As the shoot emerges and develops leaves, the plant is able to carry out photosynthesis, which provides it with the energy to continue growing. (2aii) (i) Availability of Resources: The availability of food, water, shelter, and suitable habitat directly influences the population size. (ii) Predation: The presence of predators can limit the population size of organisms as they prey on them, causing a decrease in the population. (iii) Competition: Competition for limited resources, such as food and territory, can limit the population size of organisms as individuals have to compete for these resources. (iv) Disease and Parasites: The presence of diseases and parasites can negatively impact the population size by causing morbidity and mortality. (2bi) -Bush Burning: (PICK ANY TWO) (i) Loss of vegetation: Bush burning destroys plants, resulting in a loss of habitat and decreased biodiversity. (ii) Soil degradation: Intense heat from bush burning can lead to soil degradation, reducing its fertility and ability to support plant growth. (iii) Air pollution: Bush burning releases large amounts of smoke and pollutants into the air, contributing to air pollution and affecting air quality. (iv) Disruption of natural cycles: Bush burning can disrupt natural ecological cycles, such as nutrient cycling and succession. -Fertilizer Application: (PICK ANY TWO) (i) Eutrophication: Overuse or improper application of fertilizers can lead to eutrophication, where excessive nutrients enter water bodies, leading to algal blooms and oxygen depletion. (ii) Soil pollution: Certain fertilizers can contain harmful chemicals that can pollute the soil, affecting soil quality and the health of organisms living in it. (iii) Biodiversity loss: Fertilizer application can favor the growth of certain plant species, leading to a decrease in biodiversity as they outcompete other species. (iv) Water pollution: Runoff from excessive fertilizer application can enter water bodies, contaminating them and affecting aquatic ecosystems. -Use of Pesticides: (PICK ANY TWO) (i) Harm to non-target organisms: Pesticides can harm not only the targeted pests but also beneficial organisms such as pollinators, natural predators, and soil organisms, affecting biodiversity. (ii) Bioaccumulation and biomagnification: Some pesticides can accumulate in the body tissues of organisms and can become more concentrated as they move up the food chain, posing a risk to higher-level consumers. (iii) Soil and water contamination: Pesticides can leach into the soil and be carried into groundwater or runoff into water bodies, causing pollution and affecting aquatic ecosystems. (iv) Development of pesticide resistance: Overuse of pesticides can lead to the development of resistance in target pests, making them harder to control and requiring stronger and potentially more harmful pesticides. (2bii) (i) Pulmonary Respiration (ii) Cutaneous Respiration (iii) Buccopharyngeal Respiration

*NECO GCE BIOLOGY* (2ai) The process involves the activation of dormant tissues within the seed, leading to the development of a young plant includes: (i) Imbibition: The seed absorbs water from the soil, causing it to swell and activate biochemical processes within the seed. (ii) Activation of Enzymes: The imbibed water activates enzymes within the seed, which initiate the metabolic processes necessary for germination. (iii) Mobilization of Stored Energy: The stored energy reserves, such as starch and proteins, within the seed are broken down into simple sugars to provide energy for the growing embryo. (iv) Growth of the Embryo: The embryo grows, and the radicle (primary root) emerges from the seed, followed by the emergence of the shoot, which develops into the stem and leaves. (v) Photosynthesis: As the shoot emerges and develops leaves, the plant is able to carry out photosynthesis, which provides it with the energy to continue growing. (2aii) (i) Availability of Resources: The availability of food, water, shelter, and suitable habitat directly influences the population size. (ii) Predation: The presence of predators can limit the population size of organisms as they prey on them, causing a decrease in the population. (iii) Competition: Competition for limited resources, such as food and territory, can limit the population size of organisms as individuals have to compete for these resources. (iv) Disease and Parasites: The presence of diseases and parasites can negatively impact the population size by causing morbidity and mortality. (2bi) -Bush Burning: (PICK ANY TWO) (i) Loss of vegetation: Bush burning destroys plants, resulting in a loss of habitat and decreased biodiversity. (ii) Soil degradation: Intense heat from bush burning can lead to soil degradation, reducing its fertility and ability to support plant growth. (iii) Air pollution: Bush burning releases large amounts of smoke and pollutants into the air, contributing to air pollution and affecting air quality. (iv) Disruption of natural cycles: Bush burning can disrupt natural ecological cycles, such as nutrient cycling and succession. -Fertilizer Application: (PICK ANY TWO) (i) Eutrophication: Overuse or improper application of fertilizers can lead to eutrophication, where excessive nutrients enter water bodies, leading to algal blooms and oxygen depletion. (ii) Soil pollution: Certain fertilizers can contain harmful chemicals that can pollute the soil, affecting soil quality and the health of organisms living in it. (iii) Biodiversity loss: Fertilizer application can favor the growth of certain plant species, leading to a decrease in biodiversity as they outcompete other species. (iv) Water pollution: Runoff from excessive fertilizer application can enter water bodies, contaminating them and affecting aquatic ecosystems. -Use of Pesticides: (PICK ANY TWO) (i) Harm to non-target organisms: Pesticides can harm not only the targeted pests but also beneficial organisms such as pollinators, natural predators, and soil organisms, affecting biodiversity. (ii) Bioaccumulation and biomagnification: Some pesticides can accumulate in the body tissues of organisms and can become more concentrated as they move up the food chain, posing a risk to higher-level consumers. (iii) Soil and water contamination: Pesticides can leach into the soil and be carried into groundwater or runoff into water bodies, causing pollution and affecting aquatic ecosystems. (iv) Development of pesticide resistance: Overuse of pesticides can lead to the development of resistance in target pests, making them harder to control and requiring stronger and potentially more harmful pesticides. (2bii) (i) Pulmonary Respiration (ii) Cutaneous Respiration (iii) Buccopharyngeal Respiration

*NECO GCE BIOLOGY* (3ai) DRAW THE DIAGRAM [https://i.ibb.co/ncCqcfJ/bio3ai.jpg] (3aii) (PICK ANY TWO) (i) Yeast is commonly used in the production of bread to make it rise. (ii) Yeast plays a crucial role in the fermentation process of brewing beer and making wine. (iii) Yeast is used in the production of bioethanol, a renewable source of energy. (iv) Yeast is used to produce various pharmaceutical products, including vaccines, enzymes, and antibiotics. (3bi) -Xylem: (PICK ANY ONE) (i) It Transports water and nutrients from the roots to the leaves of the plant. (ii) It provides mechanical support to the plant. (iii) It facilitates the movement of minerals and hormones within the plant. (iv) It helps in the process of photosynthesis by supplying water to the leaves. -Phloem: (PICK ANY ONE) (i) It transports organic materials such as sugars and amino acids from the leaves to other parts of the plant. (ii) It provides a pathway for the distribution of nutrients and hormones throughout the plant. (iii) It helps in the process of growth and development of the plant. (iv) It allows for the storage and distribution of carbohydrates in the plant. -Artery: (PICK ANY ONE) (i) It carries oxygenated blood from the heart to the tissues and organs of the body. (ii) It distributes nutrients, hormones, and other substances to different parts of the body. (iii) It helps regulate blood pressure through the contraction and relaxation of its smooth muscle walls. (iv) It facilitates the removal of waste products, such as carbon dioxide, from the tissues. -Vein: (PICK ANY ONE) (i) It carries deoxygenated blood from the tissues and organs of the body back to the heart. (ii) It assists in the removal of waste products, such as carbon dioxide, from the tissues. (iii) It returns excess fluids and proteins back to the bloodstream. (iv) It helps regulate blood flow and maintain blood pressure. (3bii) (PICK ANY THREE) (i) Water and nutrient uptake: Transpiration facilitates the movement of water and nutrients from the roots to the leaves of plants. As water is lost through transpiration, it creates a lower pressure in the leaf cells, which pulls water and nutrients up from the roots. (ii) Cooling effect: Transpiration helps to cool down plants by evaporating water from the leaves. This process, known as evaporative cooling, helps regulate the temperature of plant tissues and prevents overheating. (iii) Photosynthesis: Transpiration provides the necessary water for the process of photosynthesis. Water is one of the essential components for photosynthesis, and without transpiration, plants would not be able to produce glucose and oxygen. (iv) Plant structure and support: Transpiration plays a role in maintaining plant structure and supporting tall plants. As water is lost through transpiration, it creates a negative pressure in the xylem vessels, which helps to pull water and provide support to the plant. (v) Transport of minerals: Transpiration creates a continuous flow of water and minerals from the roots to other parts of the plant. This transport system ensures that essential minerals, such as nitrogen and phosphorus, are distributed evenly throughout the plant for growth and development. (3biii) (i) Use of contraceptive pills (ii) Use of condoms (iii) Use of intrauterine devices (IUDs)

*NECO GCE BIOLOGY* (1ai) Organic evolution refers to the gradual change in the genetic makeup of a population over generations, resulting in the development of new species from pre-existing ones. It involves the processes of natural selection and genetic variation. (1aii) (i) Animals (ii) wind (1aiii) (i) Photosynthesis is a process in which plants convert carbon dioxide and water into glucose and oxygen, using light energy. *While* Respiration is a process in which cells break down glucose to produce energy, releasing carbon dioxide and water as byproducts. (ii) Photosynthesis occurs in the chloroplasts of plant cells, *while* respiration occurs in the mitochondria of both plant and animal cells. (1aiv) (PICK ANY TWO) (i) Cell elongation: Auxin promotes elongation of plant cells, leading to growth and development. (ii) Apical dominance: Auxin inhibits the growth of lateral buds, directing the plant's growth towards the main apical bud. (iii) Tropisms: Auxin plays a role in tropisms, such as phototropism (growth towards light) and gravitropism (response to gravity). (iv) Root formation: Auxin stimulates the formation of roots in cuttings, aiding in vegetative propagation. (1bi) Metamorphosis in houseflies (Musca domestica) involves distinct stages of development. It starts with an egg, which hatches into a larva or maggot. The larva goes through several instars, growing in size and molting its exoskeleton. After the larval stage, it enters the pupal stage, during which it undergoes internal changes and transforms into an adult housefly. The adult housefly emerges from the pupa, ready for reproduction. (1bii) (i) Cell: A cell is the basic unit of life. There are two kinds of cells: plant cells, which have a rigid cell wall made of cellulose molecules, and animal cells, which have flexible cell membranes. Cell biologists consider questions such as metabolism and other questions about structure and function within and between cells. (ii) Tissue: Tissue is made of cells that work together to perform a certain task. Muscle tissue, connective tissue, and neural tissue are some types of tissue. Histologists are an example of biologists who work at this level. (iii) Organ: An organ is a system of tissues that work together on a larger scale to do certain jobs within an animal's body. Examples of organs are the brain, heart and lungs. Anatomy is an example of a biology specialty concerned with this level. (iv) Organ System: An organ system is a group of organs that work together to perform specific bodily functions. The respiratory system, for example, uses the lungs, airways and respiratory muscles to inhale oxygen and release carbon dioxide in animals. Physiologists study the function of parts of the body as they work together. Though physiologists can work at any level of biological organization, they often answer questions related to organ systems. (v) Organism: An organism is a recognizable, self-contained individual. Organisms can be unicellular organisms such as bacteria or amoebae, or multi-cellular organisms comprised of organs and organ systems. A human being is an example of a multi-cellular organism.