Year 2 Science 2024-2025 PDF

# YEAR 2 SCIENCE | 2024 - 2025 ## Table of Contents - What is science? - Investigation Information - Marking codes and symbols. ### Biology - **Topic: Body Systems** - Part 1: Breathing System - Part 2: Circulatory System - Part 3: Nutrition and Digestive System - **Topic: Thermal E...

# YEAR 2 SCIENCE | 2024 - 2025 ## Table of Contents - What is science? - Investigation Information - Marking codes and symbols. ### Biology - **Topic: Body Systems** - Part 1: Breathing System - Part 2: Circulatory System - Part 3: Nutrition and Digestive System - **Topic: Thermal Energy Transfer** - Introduction - Conduction - Convection - Radiation ### Physics - **Topic: Compounds and Mixtures** - Introduction - Compounds ### Chemistry - **Topic: Simple Chemical Reactions** - Introduction - Combustion reactions. - Reactions of metals with acids. - Reaction of metal carbonate with acids. - **Topic: Reproduction** - Part 1: Animal Reproduction - Part 2: Plant Reproduction - **Topic: Acids and Bases** - Acids - Bases - Indicators. - pH scale - Neutralisation. ## PART 1: BREATHING SYSTEM **Learning outcomes:** You should: - Recall previous knowledge on respiration. - Understand the link between breathing and respiration. - Know the percentages of oxygen and carbon dioxide in inhaled and exhaled air. - Recall the use of limewater to show the presence of carbon dioxide in exhaled air. - Know the structure of the breathing system and its main organs. - Trace the route followed by gases during inhalation and exhalation. - Understand that oxygen enters the blood by diffusion. **Cells release the energy they need from food during the process of respiration.** The nutrients are transferred to the cells, following digestion, via the blood. For respiration to take place and for energy to be released oxygen is also needed, which we obtain from breathing in (inhalation). **The oxygen which is transferred from our lungs to the cells via the blood, reacts with the food during respiration to release energy (chemical and thermal).** **During the process of respiration, carbon dioxide and water are produced as waste products.** They are transferred, via the blood, to the lungs where they are excreted during breathing out (exhalation). ## Task 1: **(a) Complete the diagram below showing respiration in cells.** **(b) Write the word equation for respiration.** **(c) Is respiration the same as breathing?** _The breathing system allows oxygen to diffuse into the blood and carbon dioxide to diffuse out of the blood._ _The air we inhale contains 21% oxygen and 0.04% carbon dioxide._ _The air we exhale contains 16% oxygen and 4.04% carbon dioxide._ ## Task 2: **(a) What chemical can we use to prove that there are high levels of carbon dioxide in exhaled air?** **(b) Suggest why exhaled air contains less oxygen than inhaled air.** **(c) Suggest why exhaled air contains more carbon dioxide than inhaled air.** ## The diagram below shows the main parts of the breathing system. - Intercostal muscles - Rib - Bronchiole - Trachea - Bronchus - Lung - Diaphragm - Alveoli ## Task 3: **The larynx, also called voice box, is responsible for the production of sound. Label the larynx on the diagram above.** ## Task 4: **Place the following words in the correct order to indicate the route taken by air during inhalation.** You should start with the nose or mouth and finish with the blood. - Alveoli - Bronchi - Trachea - Bronchiole - Larynx **When air reaches the alveoli (found at the end of the bronchioles) oxygen diffuses into the blood.** Carbon dioxide from the blood diffuses into the alveoli. **This process is known as gas exchange.** ## Task 5: The diagram shows a single alveolus. - Blood enters - Red blood cells - Air in and out - Blood leaves - Alveolus - Bloodillary **(a) Draw an arrow on the diagram to show the direction of movement of the blood.** **(b) Draw an arrow on the diagram and label it 'oxygen' to show the movement of oxygen into the red blood cells.** **(c) Draw an arrow on the diagram and label it 'carbon dioxide' to show the movement of carbon dioxide out of the blood plasma.** ## PART 2: CIRCULATORY SYSTEM **Learning outcomes:** You should: - Understand the role of the circulatory system. - Know the route taken by the blood to and from the heart. - Understand the differences between the different types of blood vessels (arteries, veins, capillaries). - Recall the main components of the blood. - Understand the functions of the main components of blood. **The circulatory system is made up of the heart and blood vessels**. The heart is a muscular organ that pumps the blood to the lungs and the rest of the body. **The human heart is divided into two sides, the left and right**. Blood low in oxygen (deoxygenated) enters the right side of the heart, gets pumped to the lungs to get oxygenated and returns to the left side of the heart to be pumped again to the rest of the body. ## Task 1: **Fill in the blanks.** * Deoxygenated blood goes from the heart to the lungs to obtain ______ and get rid of ______. * Blood goes from the heart to the cells in the rest of the body to unload ______ for respiration and obtain ______, which is a product of respiration. ## Blood Vessels **Blood moves in tubes called blood vessels.** There are three types of blood vessels. | Blood Vessels | Description | | --------- | ----------- | | Arteries | - Thick wall with thick layer of muscle <br> - Narrow lumen <br> - High concentration of oxygen and low concentration of carbon dioxide - oxygenated blood<br> - From the heart to the rest of the body | | Veins | - Thin wall <br> - Wide lumen <br> - Valves stop blood flowing the wrong way <br> - Low concentration of oxygen and high concentration of carbon dioxide - deoxygenated blood <br> - From the body towards the heart | | Capillaries | - One-cell thick wall (single layer of cells in wall) <br> - From arteries to veins, through the organs. <br> - Situated between cells in organs. <br> - Oxygenated and deoxygenated | ## Blood Composition **Blood contains a number of different components.** ## Task 2: **Match each component of the blood to its function.** - Red blood cells - White blood cells - Platelets - Plasma **Blood is made up of several different kinds of cells floating in liquid called plasma.** The blood plasma is a pale, yellow liquid. It is mostly water, but it has many different substances dissolved in it such as glucose, antibodies and hormones. The blood plasma carries these substances from place to place in the body. There are many different blood cells floating in the plasma. **Red blood cells are the smallest cells in the human body**. They are round, with a dent in each side as though someone had pinched them between a finger and thumb. This shape is described as biconcave and increases the surface area for efficient diffusion. They do not have a nucleus, therefore have more volume (space) for transport of oxygen. The function of red blood cells is to transport oxygen around the body. To enable them to do this, they are full of the red pigment haemoglobin which transports oxygen. The blood also transports carbon dioxide. Body cells produce carbon dioxide when they respire. The carbon dioxide diffuses into the blood. When the blood reaches the lungs, the carbon dioxide leaves the blood and diffuses into the alveoli in the lungs, before being breathed out. The other cells are white blood cells. They are part of the body's defence system against invaders. There are also tiny fragments of cells in the blood called platelets, which help blood to clot after an injury. ## Task 3: **(a) Colour the arrows in the diagram above using red for oxygenated blood and blue for deoxygenated blood.** **(b) Choose a number from the diagram to match each description.** | Description | Number | | --------- | ----------- | | The deoxygenated blood travels back to the heart where it is sent to the lungs. | | | The heart pumps the oxygenated blood to all the organs of the body e.g. stomach, muscles and brain. | | | Within the tissues oxygen and glucose move from the blood into the cells where respiration takes place and carbon dioxide and other waste products are released from the cells into the blood. | | | The oxygenated blood returns to the heart. | | | The heart pumps the blood towards the lungs. | | | Gas exchange happens here; oxygen moves into the blood and carbon dioxide moves out of the blood. | | ## PART 3: NUTRITION AND DIGESTIVE SYSTEM **Learning outcomes:** You should: - Understand that a balanced diet should contain appropriate proportions of carbohydrates, proteins, lipids, fibre, vitamins (A, C and D), water and minerals (iron and calcium). - Identify the sources and describe the functions of carbohydrates, proteins, lipids, fibre, vitamins (A, C and D), water and minerals (iron and calcium). - Class practical: Recall that two examples of carbohydrates are starch and glucose and be able to identify them in food substances using the appropriate tests. - Know the symptoms of vitamin and mineral deficiency. - Identify the main parts of the human digestive system. - Define digestion as the breakdown of food into tiny soluble substances that can be absorbed in the bloodstream. - Understand the importance of enzymes in the process of digestion. ## Nutrients in Food **A balanced diet should contain appropriate proportions of different nutrients.** | Nutrient | Importance | Food Items that Provide a Rich Source | | --------- | ----------- | ----------- | | Carbohydrates | - Examples of carbohydrates include starch and glucose. <br> - Main 'fuel' for supplying energy to cells through the process of respiration. e.g. muscle cells need carbohydrates to release of energy for movement. | - Potatoes <br> - Bread <br> - Honey <br> - Pasta <br> - Fruits | | Proteins | - Growth of organism to produce new cells, which is an important process for growth. <br> - Repair of organism, for example in the case of injury. | - Fish <br> - Meat <br> - Dairy <br> - Beans <br> - Peas <br> - Nuts | | Lipids (fats or oils) | - For long-term storage of energy, fat is deposited into certain parts of the body. <br> - Used for insulation, preventing loss of thermal energy from the body. <br> - Fat can protect organs from damage. | - Oil <br> - Butter <br> - Nuts <br> - Egg <br> - Dairy <br> - Meat | | Water | Water is essential for all chemical reactions, such as respiration, to occur. | - Drinking water <br> - Fruits <br> - Vegetables | ## Other important substances required in our diet but in smaller quantities are fibre, vitamins and minerals. ### Fibre Our bodies require fibre in small quantities. Fibre helps in preventing constipation, by keeping our intestine healthy. It can also help to reduce our risk of developing colon cancer. Fibre is found in all fruits, vegetables, brown bread and cereals. ### Vitamins Vitamins are not a source of energy but are essential in small quantities in our diet for the normal functioning of our bodies. Lack of certain vitamins (vitamin deficiency) can cause disease. There are many types of vitamins e.g. A, C, and D, as shown below. | Vitamin | Importance | Deficiency Symptoms | Sources | | --------- | ----------- | ----------- | ----------- | | A | Good vision | Dry eyes, night blindness | Carrots, liver, fish liver oil | | C | Strong gums Healthy skin | Scurvy (bleeding gums) | Citrus fruits (oranges, mandarins, lemons) | | D | Strong bones | Rickets (poor bone growth, soft bones) | Liver, egg yolk, fish liver oil. Also made in skin when exposed to sunlight.| ## Minerals Minerals are also not a source of energy but are essential in small quantities in our diet for the normal functioning of our bodies. Examples of mineral ions include iron and calcium. | Mineral Ion | Major Importance | Sources | | --------- | ----------- | ----------- | | Iron | Used to make haemoglobin. Deficiency leads to anaemia. | Meat, liver, lentils | | Calcium | Making strong teeth and bones. Deficiency leads to rickets. | Milk, cheese, yoghurt| ## Investigating Food Samples for the Presence of Carbohydrates ### A. Test for starch Testing food for the presence of starch can be done using a solution of ______. When a few drops of this solution are added to the food sample, the iodine reacts with the starch. The change in colour of iodine from ______ to ______ provides a positive indication that the food contains starch. **Experimental procedure** 1. Add 2-3 drops of iodine solution to the starch powder (positive control labelled Cp). 2. Add 2-3 drops iodine solution to a well containing water (negative control labelled Cn). 3. Add 2-3 drops iodine solution to a well containing the different food items and complete the table below. | Food Source | Observation/Colour | Results (Positive/Negative for presence of starch) | | --------- | ----------- | ----------- | | Potato | | | | Flour | | | | Sweet | | | ## B. Test for glucose For the detection of glucose in food samples we use the chemical solution ______. A few drops of the Benedict's solution are added to the food sample in a test tube and ______ in a water bath. For a positive result, a colour change is observed from ______ to ______ or ______, ______ or ______ depending on how much glucose the sample contains ('brick red' indicates the highest concentration of glucose). **Experimental procedure** 1. Add 2-3 drops of Benedict’s solution to a test tube containing a solution of glucose (positive control). 2. Add 2-3 drops of Benedict’s solution to a test tube containing a solution of water (negative control). | Food Source | Observation/Colour | Results (Positive/Negative for presence of starch) | | --------- | ----------- | ----------- | | Potato | | | | Flour | | | | Sweet | | | ## The Digestive System **Nutrients from the food that we eat (e.g. carbohydrates, proteins and lipids) can only enter our cells if they are broken down into smaller molecules.** The process through which larger Insoluble nutrient molecules (e.g. carbohydrates, proteins and lipids) are broken down into smaller soluble ones is called ______. **Digestion starts in the mouth and is completed in the small intestine.** **Digestion occurs with the help of special chemicals called ______.** With the action of enzymes, proteins, carbohydrates and lipids are ______ into smaller nutrient molecules (e.g. glucose) and can therefore be ______ through the wall of the small intestine into the blood. As blood circulates, it carries these absorbed nutrient molecules to cells around the body, which can use them for various purposes. **Parts of food that cannot be broken down are not absorbed.** These pass to the large intestine, which absorbs some of their ______ and transfers it into the blood. **The remaining substances that are not absorbed and are removed from the body through the anus.** This removal process is called ______. ## Task 1: **Number the organs of the digestive system below to show the order in which the food passes through the digestive system.** * Mouth * Oesophagus (gullet) * Duodenum * Ileum * Stomach * Colon * Rectum * Anus * Large Intestine ## Task 2: **Search online to label the following accessory organs of the digestive system: 1) liver 2) gall bladder 3) pancreas** ## Questions 1. Label the diagram of the digestive system below. 2. Describe the role of enzymes in digestion. # BODY SYSTEMS ## Mind map ### **SYSTEM** > Gets _____ and gets rid of _____ > Transports _____ around the body. * **Arteries carry** _____ blood from _____ to _____. * **Veins carry** _____ blood from _____ to _____. * **Capillaries carry** _____ blood from _____ to _____. ### The components that make up blood | Component | Function | | --------- | ----------- | | | | | | | | | | | | |