Biology Definitions - Scientific Method - Life Characteristics - Nutrition - Ecology

Oct 1, 2026

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Biology Definitions compiles key concepts across scientific inquiry and core life science topics. It explains the scientific method from observation and hypothesis through experiments, data, replication, controls, and the development of theory into principles or laws, alongside ethics. The text then defines major characteristics of life, including biogenesis, metabolism, organization, nutrition, excretion, response, and reproduction, followed by nutrition categories of biomolecules. It concludes with ecology definitions covering ecosystems, biosphere, habitats, biotic and abiotic factors, trophic levels, food chains and webs, nutrient cycling, nitrogen processes, pollution, conservation, competition, adaptation, predation, parasitism, symbiosis, and saprophytes.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages18

Reading Time45 min

AccessFree to download

Scientific Method

Observation, Hypothesis, Experiment

Data, Replicate, Control, Ethics

Characteristics of Life

Biogenesis, Metabolism, Organization

Nutrition, Excretion, Response, Reproduction

Nutrition

Biomolecules and organic compounds

Carbohydrates and phospholipids

Anabolic and catabolic reactions

Ecology

Ecosystem, biosphere, habitat, population, community

Niches, abiotic/biotic factors

Producers, consumers, trophic levels

Food chain, food web, pyramid of numbers

Nutrient recycling and nitrogen cycle

Pollution, conservation, competition

Adaptations, predation, parasitism, symbiosis

The Scientific Method • Scientific Method is a process of investigation where problems are identified, and their explanations are tested by carrying out experiments. • Observation: An unbiased, accurate report of an event. • Hypothesis: An educated guess based on observations. • Experiment: An experiment is designed to test a hypothesis. • Data: Consists of measurements, observations/information gathered during an experiment. • Replicate: A repeat of an experiment. • Control: A comparison used to provide a standard against which the actual experiment can be judged. • Theory: A hypothesis that has been supported by different experiments. • Principle/Law: A theory that has shown to be valid against long-term testing. • Ethics: Refers to whether issues are right or wrong Characteristics of Life • Continuity of life: Living things that arise from other living things of the same type (Biogenesis) • Metabolism: Sum of all the chemical reactions in an organism. • Characteristics of life: The common features shared by living organisms. • Organisation: Living things are composed of cells, tissues, organs and organ systems. • Nutrition: Process by which an organism obtains and uses food. • Excretion: Removal of waste products of metabolism. • Response: The reaction of organisms to stimuli in their environment. • Reproduction: The production of new individuals. Nutrition • Biomolecules: Molecules found in living things are composed of atoms where elements bonded together in different ratios to form biomolecules. Such as Carbohydrates, Lipids, Proteins and Vitamins. • Organic Compounds: Carbon atoms bonded together make up most of the chemical compounds in living things. • Monosaccharides: Single sugar molecules such as Glucose. • Disaccharides: 2 sugar molecules bonded together such as Sucrose, Lactose and Maltose. • Polysaccharides: Made up of many sugar molecules bonded together. E.g. -Starch, Glycogen and Cellulose • Phospholipids: Fat-like substances where one of the fatty acids is replaced/added a phosphate group. • Anabolic reactions: Convert smaller molecules into larger ones.(Using energy) • Catabolic reactions: Complex molecule is broken down to simple molecules. (Releasing energy) Ecology • Ecology: The study of the relationships of living organisms with one another and with the environment. • Ecosystem: A community of organisms and their abiotic environment. • Biosphere: Part of the earth in which life can occur. • Habitat: Place in the environment where an organism lives. • Population: All the member of the same species living in an area. • Community: Plants and animals sharing the resources of a particular habitat. • Niche: The functional role of an organism in an ecosystem. E.g.– How it feeds, what it eats, who eats it etc. • Abiotic Factors: Non-living factors. • Biotic Factors: Living Factors. • Climatic Factors: Refers to weather over a long period of time. • Edaphic factors: Aspects of the soil that influence an ecosystem such as the soil pH, soil type, moisture, air and mineral content of soil. • Producers: Autotrophs that carry out photosynthesis. • Consumers: Organisms that take in food from another organisms. • Primary Consumers: Organisms which feed directly on producers. E.g. – Rabbits • Secondary Consumers: Carnivores that feed on primary consumers. E.g.– Fox • Tertiary Consumers: Carnivores that feed on secondary consumers. E.g.– Badger • Food chain: The pathway along which energy is transferred in an ecosystem. • Food web: 2 or more interlinked food chains. • Trophic level: Is a feeding stage/energy level in a food chain. • Pyramid of numbers: Based on numbers of organisms at each trophic level in a food chain. • Nutrient recycling: The way in which elements (Carbon and Nitrogen) are exchanged between the living and non-living components of an ecosystem. • Nitrogen Fixation: Conversion of nitrogen gas into am

FAQs

What are the main steps in the scientific method described in the text?

The text outlines observation, forming a hypothesis, designing experiments, collecting data, replicating experiments, using controls for comparison, and building supported theory leading to principles or laws.

How does the document define key characteristics of life?

It defines continuity of life (biogenesis), metabolism, common characteristics of living organisms, organization by cells/tissues/organs, nutrition, excretion, response to stimuli, and reproduction of new individuals.

What topics does the ecology section cover?

It covers relationships among organisms and the environment, ecosystem and biosphere concepts, habitats and populations, ecological niches, abiotic vs biotic factors, trophic levels with producers and consumers, food chains and webs, nutrient recycling and nitrogen processes, and ecological interactions such as competition, predation, parasitism, and symbiosis.

Oct 1, 2026

Upload by Terk