Introduction to Biology: Cell Biology

Study Notes

Biology is the scientific study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy.
It encompasses a vast and diverse range of subjects, from the molecular mechanisms within cells to the interactions of ecosystems.
Key themes in biology include evolution, genetics, cell biology, ecology, and physiology.
Biology relies on scientific methods, including observation, hypothesis formation, experimentation, and data analysis.

Cells are the fundamental units of life.
All living organisms, from bacteria to humans, are composed of cells.
Cells exhibit complex structures and functions.
Prokaryotic cells lack a nucleus and membrane-bound organelles.
Eukaryotic cells contain a nucleus and membrane-bound organelles.
Key organelles include mitochondria, endoplasmic reticulum, Golgi apparatus, and chloroplasts (plant cells).
Cells carry out various processes, including metabolism, reproduction, and transport.

Genetics is the study of heredity and variation in organisms.
Genes are the units of heredity that determine traits.
Genes are composed of DNA, a double-helix structure.
DNA carries the genetic code, which dictates protein synthesis.
Genes can mutate, leading to variations in traits.
Chromosomes are structures that carry genes.
Mendelian genetics describes patterns of inheritance based on experiments with pea plants.
Modern genetics involves understanding gene expression, regulation, and interactions.

Evolution is the process of change in heritable characteristics of biological populations over successive generations.
Natural selection is a key mechanism of evolution.
Organisms with traits better suited to their environment are more likely to survive and reproduce.
This leads to the accumulation of advantageous traits in a population over time.
Evolutionary relationships can be visualized using phylogenetic trees.
Fossils provide evidence of past life forms and evolutionary history.
Common ancestry links all life on Earth.

Physiology is the study of the physical and chemical processes within living organisms.
Organisms maintain homeostasis through various physiological processes.
This involves regulating internal conditions like temperature, pH, and water balance.
Cellular respiration and photosynthesis are fundamental physiological processes.
Digestion and nutrient absorption are critical for energy and growth.
Nervous and endocrine systems control physiological functions.
Transport systems, like the circulatory system, are vital for distributing materials throughout the body.