Introduction to Biology and Cell Biology

Introduction to Biology

• Biology is the natural science studying living organisms (animals, plants, fungi, protists, archaea, and bacteria).
• It encompasses various levels of biological organization, from molecules to ecosystems.
• Key biological themes include evolution, genetics, ecology, and cell biology.
• Studying biology helps understand the complexity of life processes.

Cell Biology

• Cells are the fundamental units of life.
• All living organisms are composed of cells.
• Cells share fundamental characteristics, including a plasma membrane, cytoplasm, and genetic material.
• Prokaryotic cells lack a nucleus and membrane-bound organelles.
• Eukaryotic cells have a nucleus and membrane-bound organelles.
• Cell structures and organelles carry out specific functions for cellular survival.

Molecular Biology

• Molecular biology examines the biological activity of molecules in living organisms.
• It focuses on the structure and function of DNA, RNA, proteins, and other biomolecules.
• Understanding molecular interactions is crucial for comprehending cellular processes.
• The central dogma describes the flow of genetic information: DNA to RNA to protein.
• DNA replication, transcription, and translation are essential molecular processes.

Genetics

• Genetics investigates genes, heredity, and variation in organisms.
• Genes are DNA segments instructing protein synthesis.
• They control traits and characteristics passed from parents to offspring.
• Mendelian genetics explains inheritance patterns via dominant and recessive alleles.
• Modern genetics studies complex traits and applies genetic technologies.

Evolution

• Evolution is the process of species change over time.
• Natural selection is a key evolutionary mechanism: organisms with advantageous traits reproduce more.
• Evidence for evolution comes from comparative anatomy, molecular biology, and the fossil record.
• Phylogenetic trees visualize evolutionary relationships between organisms.
• Understanding evolution clarifies the diversity of life.

Ecology

• Ecology studies the relationship between organisms and their environment.
• It examines populations, communities, ecosystems, and the biosphere.
• Factors like climate, resources, and interspecies interactions influence ecological processes.
• Biodiversity is the variety of life forms in an ecosystem.
• Conservation biology protects endangered species and ecosystems.

Physiology

• Physiology investigates how organisms function.
• It explores mechanisms underlying biological processes (digestion, respiration, reproduction).
• Organ systems work together to maintain homeostasis.
• Physiology is crucial for healthcare and agriculture.

Microbiology

• Microbiology studies microorganisms (bacteria, viruses, fungi, protists).
• Microorganisms play vital roles in ecosystems and human health.
• Some are beneficial, others cause diseases.
• Microbiological techniques are essential for research.

Bioethics

• Bioethics examines ethical issues in biological research and applications.
• Topics include genetic engineering, stem cell research, and animal welfare.
• Ethical considerations are critical for responsible and beneficial biological knowledge applications.