Define environment and community. Describe the carbon cycle, including processes, organisms, and human impacts.

You're on a roll — Here are the answers to your questions: 5. Define the following i. Environment: The environment* refers to the sum total of all living (biotic) and non-living (abiotic) factors and conditions that surround an organism or a community, influencing its survival, development, and evolution. ii. Community: A community* in biology is an interacting group of various species in a common location. It refers to the populations of different species living and interacting in the same area. 6. Figure 3 shows the carbon cycle in an ecosystem. i. Name the process taking place at Y. Photosynthesis ii. What process releases carbon dioxide from the dead matter? Decomposition (or Respiration by decomposers) iii. What is the collective name for the organisms that release carbon dioxide from dead matter? Decomposers (e.g., bacteria and fungi) b. Mention any two human activities which contribute to an accumulation of carbon dioxide in the atmosphere. • Burning of fossil fuels: Such as coal, oil, and natural gas for energy production, transportation, and industrial processes. • Deforestation: The clearing of forests for agriculture, logging, or urbanization, which reduces the number of trees available to absorb carbon dioxide through photosynthesis. c. Explain how these activities have contributed to climate change. The burning of fossil fuels and deforestation release large amounts of carbon dioxide (CO_2) into the atmosphere. CO_2 is a greenhouse gas that traps heat from the sun, leading to an increase in the Earth's average temperature, a phenomenon known as global warming. This warming causes changes in global weather patterns, leading to climate change*, which manifests as more frequent extreme weather events, altered rainfall patterns (e.g., droughts), and rising sea levels. 7. Define the following i. Osmosis: Osmosis* is the net movement of water molecules across a selectively permeable membrane from a region of higher water concentration (lower solute concentration) to a region of lower water concentration (higher solute concentration). ii. Diffusion: Diffusion* is the net movement of particles (atoms, ions, or molecules) from a region of higher concentration to a region of lower concentration, down a concentration gradient. 8. Explain how energy flows in tropical savanna ecosystem In a tropical savanna ecosystem, energy flow begins with the sun. Producers: Plants (grasses, shrubs, scattered trees) capture solar energy through photosynthesis* and convert it into chemical energy stored in organic compounds. Primary Consumers (Herbivores): Animals like zebras, wildebeest, and antelopes feed on these plants, obtaining energy. Secondary Consumers (Carnivores/Omnivores): Predators such as lions, cheetahs, and hyenas consume the herbivores, transferring energy up the food chain. Tertiary Consumers: Larger predators may feed on secondary consumers. Decomposers: When any organism dies, decomposers (bacteria and fungi) break down the dead organic matter, returning nutrients to the soil but releasing energy as heat. At each transfer from one trophic level to the next, a significant amount of energy (approximately 90%) is lost as heat due to metabolic processes, respiration, and incomplete consumption, meaning only about 10% of the energy is transferred to the next level. This unidirectional flow of energy creates a food web and limits the number of trophic levels in an ecosystem. 9. State any two adaptations of red blood cells for their function • Biconcave disc shape: This shape increases the surface area to volume ratio, allowing for more efficient diffusion of oxygen and carbon dioxide across the cell membrane. It also provides flexibility, enabling red blood cells to squeeze through narrow capillaries. • Presence of hemoglobin: Red blood cells are packed with hemoglobin*, a protein that contains iron and binds reversibly with oxygen, allowing for efficient transport of oxygen from the lungs to the body tissues. Got more? Send 'em 📸