Introduction to Biology and Cell Biology

Introduction to Biology

• Biology is the scientific study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy.
• It encompasses a vast range of disciplines, from molecular biology to ecology.
• Key themes in biology include evolution, interdependence, and the interconnectedness of life.
• Biological systems at different levels, from molecules to ecosystems, show hierarchy and emergent properties.

Cell Biology

• Cells are the basic units of life.
• Prokaryotic cells (bacteria and archaea) lack a nucleus and membrane-bound organelles.
• Eukaryotic cells (plants, animals, fungi, and protists) have a nucleus and membrane-bound organelles.
• The cell membrane regulates the passage of substances into and out of the cell.
• Cellular processes like respiration, photosynthesis, and protein synthesis are essential for life.
• Mitochondria are the powerhouses of the cell, generating ATP.
• Chloroplasts are found in plant cells and perform photosynthesis.
• DNA is the hereditary material in cells, carrying genetic information.
• Genes are segments of DNA that code for specific proteins.

Genetics

• Genetics is the study of heredity and variation in organisms.
• DNA carries genetic information in the form of genes.
• Genes determine traits of an organism.
• Mitosis is the process of cell division that results in two identical daughter cells.
• Meiosis is the process of cell division that results in gametes (sex cells).
• Mendelian genetics describes the fundamental principles of inheritance.
• Non-Mendelian inheritance patterns exist beyond simple dominant-recessive relationships.
• Genetic mutations can lead to changes in traits and sometimes diseases.
• Biotechnology uses genetic engineering to modify organisms.

Ecology

• Ecology is the study of interactions between organisms and their environment.
• Ecosystems encompass biotic (living) and abiotic (non-living) components.
• Communities are groups of interacting populations within an ecosystem.
• Energy flows through ecosystems in food webs.
• Nutrients cycle within ecosystems.
• Key ecological concepts include competition, predation, symbiosis, and succession.
• Biodiversity is the variety of life in an ecosystem.
• Factors like climate, habitat, and resources influence populations and communities.

Evolution

• Evolution is the change in the heritable characteristics of biological populations over successive generations.
• Natural selection is a key mechanism of evolution, favoring traits that enhance survival and reproduction.
• Adaptation is the evolutionary process where organisms become better suited to their environment.
• Speciation is the formation of new species through evolutionary processes.
• Evidence for evolution comes from fossil records, comparative anatomy, and molecular biology.
• Genetic drift and gene flow can also influence evolutionary change.

Physiology

• Physiology is the study of how organisms function.
• Organisms display complex physiological systems responsible for their survival.
• These systems include nervous, endocrine, circulatory, respiratory, and digestive systems in animals.
• Plants have their own unique physiological mechanisms to support life.
• Homeostasis refers to the maintenance of a stable internal environment in an organism.
• Each organism has evolved specific physiological processes to adapt to their environment.