Introduction to Human Biology

Human Biology Introduction

• Biology is the study of living organisms and how they interact with each other and the environment
• Biology examines structure, function, growth, taxonomy, origin, evolution, and distribution of living things
• Biology has a direct impact on our lives, especially in medicine, where advances improve health care daily.

Biology and Medicine

• Biological knowledge is used to stop infectious diseases (e.g., flu, tuberculosis, malaria)
• Cure genetic disorders (e.g., cystic fibrosis, muscular dystrophy)
• Study the Earth's ability to sustain the human population, which is increasingly strained.

The Characteristics of Life

• All living organisms share basic characteristics: organized, acquire materials and energy, homeostatic, respond to stimuli, reproduce and grow, and have an evolutionary history.

Organization of Living Things

• Living things are highly organized, from cells to organ systems.
• Single-celled organisms are self-sufficient
• Multicellular organisms have cells organized into tissues, organs, and organ systems
• Levels of biological organization extend beyond the individual organism: population, community, ecosystem, and biosphere

Acquiring Materials and Energy

• Organisms require energy for life processes.
• Most energy on Earth comes from the sun
• Plants capture sunlight and produce complex molecules (glucose) through photosynthesis
• Animals obtain energy by consuming plants or other animals.

Homeostasis

• Homeostasis is the ability of a cell or organism to maintain internal conditions.
• Human organ systems work to maintain homeostasis
• For example, maintaining body temperature (around 36.5-37.5°C).

Living Organisms Respond

• Homeostasis requires responding to stimuli
• Responses to external stimuli are often apparent as movement.

Reproduction and Development

• All organisms reproduce to create copies
• Unicellular organisms reproduce through simple division
• Multicellular organisms involve sperm and egg union, followed by cell division and maturation.

Evolution

• Evolution is the process by which populations change over time
• Natural selection is the mechanism driving evolution
• Individuals with advantageous variations are more likely to survive and reproduce, passing on their traits.

Classification of Living Organisms

• Living organisms are classified using a variety of methods to study relationships
• This classification system is called taxonomy
• Carolus Linnaeus's system, using binomial nomenclature is important for classifying and organizing known organisms

Linnaean System of Classification

• The Linnaean classification system is a hierarchical system with levels.
• In order from highest to lowest: Kingdom, Phylum, Class, Order, Family, Genus, Species.
• Scientific names are written in italics, with the genus capitalized and the species in lowercase.

Domains of Life

• Living organisms are categorized into three domains: Bacteria, Archaea, and Eukarya
• Bacteria and Archaea are prokaryotes that do not have a nucleus
• Eukarya includes organisms with a nucleus. (i.e., protists, plants, fungi, and animals)

Investigating a Problem-Scientific Method

• Investigating a problem follows a systematic approach called the scientific method.
• Make observations.
• Form a hypothesis.
• Research background information.
• Generate a prediction
• Conduct an experiment.
• Collect and analyze data.
• Draw conclusions.

Critical Thinking

• Critical thinking involves systematically and objectively judging information.

Explore the fascinating world of human biology, where you'll learn about the fundamental characteristics of life and the organization of living organisms. Understand the critical role biology plays in medicine and its impact on public health and diseases. This quiz will help reinforce your knowledge of key biological concepts.