Life Science Praxis 5442 Questions and Answers Latest Version Graded A+

Life Science Praxis 5442 Questions and Answers Latest Version Graded A+ How do enzymes affect the rate of biochemical reactions? They speed up reactions by lowering the activation energy What process do plants use to convert sunlight into chemical energy? Photosynthesis What molecule carries genetic information in most living organisms? DNA How is oxygen produced in photosynthesis? By splitting water molecules during the light-dependent reactions What structure controls the movement of substances into and out of a cell? The cell membrane 2 Why is mitosis important for multicellular organisms? It allows for growth and repair by producing identical cells What organelle is responsible for protein synthesis? Ribosomes What is the role of chlorophyll in photosynthesis? To absorb light energy from the sun How do traits pass from parents to offspring? Through inherited genes in DNA What is the result of meiosis in humans? Four genetically unique gametes with half the number of chromosomes What is a dominant allele? An allele that expresses its trait even when only one copy is present 3 What role do decomposers play in an ecosystem? They break down dead matter and recycle nutrients How is energy transferred in a food chain? From producers to consumers to decomposers What is the basic unit of structure and function in living things? The cell Why is biodiversity important in ecosystems? It increases stability and resilience to change What is the function of the xylem in plants? To transport water and minerals from roots to leaves What happens during cellular respiration? Glucose is broken down to release energy for cellular activities 4 Why are bacteria considered prokaryotes? Because they lack a true nucleus and membrane-bound organelles What is the function of the nucleus in a eukaryotic cell? It stores genetic material and controls cell activities What process allows oxygen and carbon dioxide to move across cell membranes? Diffusion