Introduction to Life Processes

Introduction to Life Processes

• Living organisms perform various life processes, such as growth, respiration, digestion, excretion, and reproduction.
• These processes distinguish them from non-living things.

Nutrition

• Nutrition is the intake of nutrients and their utilization for biological activities.
• Autotrophs produce their own food (e.g., plants, algae).
• Heterotrophs obtain food from other organisms (e.g., animals, humans).
  • Holozoic obtain solid or liquid food (e.g., Amoeba, humans).
  • Parasitic obtain food from a host (e.g., worms).
  • Saprophytic obtain food from dead or decayed organisms (e.g., yeast, mushrooms).

Photosynthesis

• Autotrophs perform photosynthesis, a process to prepare food.
• Chlorophyll-containing cells use carbon dioxide and water in the presence of light to produce glucose, releasing oxygen as a byproduct.
• 6CO2 + 12H₂O → C₆H₁₂O₆ + 6O₂ + 6H₂O (Equation for photosynthesis)

Nutrition in Humans

• Steps of human nutrition include ingestion, digestion, absorption, assimilation, and egestion.
• Digestion involves converting large, complex food molecules into simpler forms.
• Organs of the digestive system include mouth, esophagus, stomach, intestines, liver, pancreas, and others.

Respiration

• Respiration is the breakdown of glucose to release energy using oxygen. This is then used by cells for bodily functions.

• The equation for aerobic respiration is C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy.

Transportation in Humans and Plants

• Transportation in humans involves the circulatory system which is made up of the heart, blood vessels, and blood.
• In plants, xylem transports water and minerals, while phloem transports food.
• Blood pressure is the force exerted by blood on the walls of the blood vessels.

Excretion in Humans and Plants

• Excretion in humans involves removing metabolic wastes such as urea and excess water through the kidneys.
• Plants expel carbon dioxide and excess water through processes like transpiration and through stomata.

Control and Coordination in Humans

• The nervous system and endocrine system coordinate and control actions.
• Neurons are the basic units of the nervous system.
• Neurons transmit impulses to coordinate various bodily activities.
• Synapse is a point of contact between neurons, where signals are passed via chemical neurotransmitters.

Control and Coordination in Plants

• Plants also exhibit coordination and control through hormones (e.g., auxin).
• Growth responses to stimuli are called tropisms (e.g., phototropism, geotropism).

Reproduction

• Reproduction is the process by which new organisms are produced.
• Asexual reproduction is reproduction with a single parent, whereas sexual reproduction involves two parents.

Heredity

• Genetics is the study of how traits are passed from parents to offspring.
• The study of heredity includes Mendel's laws (dominance, segregation, and independent assortment).

Evolution

• Evolution is the gradual development of organisms over time.
• Natural selection and genetic variation drive evolution.
• Fossils provide evidence of past life and evolutionary changes.

Explore the fundamental life processes that distinguish living organisms from non-living ones. This quiz covers essential topics such as nutrition, photosynthesis, and types of nutritional intake in different organisms. Test your knowledge on how organisms perform vital life functions.