Living Organisms Characteristics and Classification

Living Organisms: Seven Characteristics

• Movement: An organism's ability to change its position or place.
• Respiration: Chemical reactions in organisms breaking down nutrients to release energy.
• Sensitivity: The ability to detect and respond to changes in the internal or external environment.
• Growth: A permanent increase in size and mass.
• Reproduction: Creation of new organisms of the same kind.
• Excretion: Removal of waste products of metabolism.
• Nutrition: Obtaining materials for energy, growth, and development.

Classification

• Species: A group of organisms with similar traits that can interbreed and produce fertile offspring.
• Binomial System: A naming system for organisms, using the genus and species names (e.g., Homo sapiens).
• Classification Usefulness: Classifying organisms helps identify different species and understand evolutionary relationships.

DNA

• Deoxyribonucleic Acid (DNA): A molecule with a double helix structure, containing genetic instructions for life.
• Chromosomes: Long, thread-like structures within the nucleus, composed of DNA.
• DNA Structure: DNA is composed of two parallel strands connected by bases (adenine, thymine, guanine, and cytosine).

Vertebrates

• Fish: Scales, gills, cold-blooded, lay eggs, fins.
• Mammals: Hair/fur, warm-blooded, give birth to live young, produce milk.
• Amphibians: Moist skin, breathe through lungs/skin, cold-blooded, lay eggs.
• Reptiles: Scales, breathe through lungs, cold-blooded, lay eggs.
• Birds: Feathers, breathe through lungs, warm-blooded, lay eggs.

The Five Kingdoms

• Animals, Plants, Fungi, Protists, Prokaryotes are the five kingdoms.

Features of Different Kingdoms

• Animals: Multicellular, contain a nucleus, lack cell walls or chloroplasts, obtain energy from other living organisms.
• Plants: Multicellular organisms with cell walls, often containing chloroplasts. They perform photosynthesis for energy and can be made of roots, stems, and leaves.
• Fungi: Usually multicellular (some unicellular), cell walls made of chitin. They obtain nourishment by absorbing organic matter.
• Protists: Organisms that can be multicellular or unicellular, containing a nucleus. Some have chloroplasts, and others obtain nourishment from other organisms or photosynthesis.
• Prokaryotes: Usually unicellular, lack a true nucleus and other membrane-bound organelles, single circular DNA, have cell walls made of peptidoglycan.

Viruses

• Viruses are not part of a classification system.
• They are not living organisms.
• They rely on host cells' metabolic processes.
• A virus is an assembly of RNA or DNA enclosed in a protein coat.

The Plant Kingdom

• The plant kingdom includes various groups like mosses, liverworts, ferns, conifers, and flowering plants.
• Ferns reproduce through spores, not flowers.
• Flowering plants reproduce through flowers and seeds, with seeds forming inside an ovary

Flowering Plants: Groups

• Monocots: One cotyledon, parallel veins, fibrous root system, petals in multiples of 3
• Dicots: Two cotyledons, net-like veins, taproot system, petals in multiples of 4 or 5