Draw and interpret nutrient cycles Do this activity on your own. 1. Read the information about nutrient cycles in ecosystems. 2. Write down the missing words in the following sentences. 2.1 Carbon moves from the atmosphere to plants by the process of __ (1) 2.2 __ is the process by which carbon moves from living things to the atmosphere. (1) 2.3 The process of __ is the opposite of evaporation. (1) 2.4 Plants get water and nutrients from the soil by the process of __ (1) 2.5 The constant movement of nutrients between living organisms and the environment is called a __ (1) (8) 3. Draw and label a diagram to explain the water cycle. 3.1 Why do living organisms need nitrogen? 3.2 In what forms do plants absorb nitrogen? 3.3 How do animals get nitrogen? 3.4 Describe the role of the following types of bacteria in the nitrogen cycle: 3.4.Nitrogen-fixing bacteria 3.4.2 Nitrifying bacteria 3.4.3 Denitrifying bacteria List three ways that a farmer can increase the nitrogen levels in oull. (1) Total marks: [21]

2.1 Carbon moves from the atmosphere to plants by the process of **photosynthesis**.<br /><br />2.2 **Respiration** is the process by which carbon moves from living things to the atmosphere.<br /><br />2.3 The process of **condensation** is the opposite of evaporation.<br /><br />2.4 Plants get water and nutrients from the soil by the process of **absorption**.<br /><br />2.5 The constant movement of nutrients between living organisms and the environment is called a **nutrient cycle**.<br /><br />3. Draw and label a diagram to explain the water cycle.<br /><br />3.1 Living organisms need nitrogen for the synthesis of proteins and nucleic acids, which are essential for growth and reproduction.<br /><br />3.2 Plants absorb nitrogen in the form of nitrate (NO3-) and ammonium (NH4+).<br /><br />3.3 Animals obtain nitrogen by consuming plants or other animals that have ingested nitrogen-containing compounds.<br /><br />3.4.1 Nitrogen-fixing bacteria, such as Rhizobium, convert atmospheric nitrogen (N2) into ammonia (NH3), which can be used by plants.<br /><br />3.4.2 Nitrifying bacteria, such as Nitrosomonas and Nitrobacter, convert ammonia into nitrites (NO2-) and then into nitrates (NO3-), making nitrogen available for plant uptake.<br /><br />3.4.3 Denitrifying bacteria, such as Pseudomonas and Clostridium, convert nitrates back into atmospheric nitrogen (N2), completing the nitrogen cycle.<br /><br />Three ways a farmer can increase the nitrogen levels in soil:<br />1. **Fertilization**: Applying nitrogen-rich fertilizers such as ammonium nitrate or urea.<br />2. **Crop Rotation**: Planting nitrogen-fixing crops like legumes (e.g., beans, peas) in rotation with other crops.<br />3. **Composting**: Adding compost to the soil, which decomposes organic matter and releases nitrogen back into the soil.