(A) Polio is a highly infectious viral disease caused by the poliovirus that spreads mainly through contaminated food, water, or feces. The symptoms of polio range from fever, headache, fatigue, to muscle pain, stiffness, and paralysis. The prevention of polio involves vaccination, maintaining good hygiene and sanitation, and avoiding contact with infected people or contaminated materials.
(B) Bio-fuel is a type of renewable energy derived from organic matter, such as plants, animal waste, or algae. It can be used to replace fossil fuels and reduce greenhouse gas emissions. Bio-fuels are helpful in promoting clean energy because they are renewable, biodegradable, and emit less carbon dioxide and other harmful pollutants.
(C) Carbohydrates are one of the three macronutrients (along with protein and fat) that provide energy to the body. They are made up of sugars, starches, and fibers and are found in various foods such as grains, fruits, and vegetables. Carbohydrates are digested in several steps in the human body, including the mouth, stomach, and small intestine, where enzymes break them down into simple sugars that are absorbed into the bloodstream.
(D) The cell structure is the basic unit of life and is composed of various components such as the cell membrane, cytoplasm, nucleus, and organelles. Animal cells and plant cells have several differences, including:
- Plant cells have a cell wall made of cellulose, while animal cells do not.
- Plant cells have chloroplasts for photosynthesis, while animal cells do not.
- Plant cells have a large central vacuole that stores water, while animal cells have smaller vacuoles.