Introduction to Biology

Study Notes

Introduction to Biology

Biology is the study of life and living organisms, encompassing their structure, function, growth, origin, evolution, distribution, and taxonomy.
It is a broad field encompassing many sub-disciplines.
The study of life examines a wide range of topics from the molecular to ecosystem levels.
It involves the application of scientific methods to understand and explain natural phenomena.

Characteristics of Living Organisms

Living organisms exhibit several key characteristics:
- Organization: Living things possess a complex, hierarchical organization from atoms to molecules, cells, tissues, organs, organ systems, and ultimately organisms.
- Metabolism: Organisms carry out chemical reactions to acquire and use energy. This includes anabolism (building molecules) and catabolism (breaking down molecules).
- Responsiveness: Living organisms respond to internal and external stimuli.
- Growth and Development: Living things increase in size and complexity, following specific patterns during development.
- Reproduction: Organisms create new life, either asexually or sexually.
- Adaptation: Populations of organisms adapt over time to their environment through natural selection.
- Homeostasis: Organisms maintain relatively stable internal conditions, such as temperature and pH.

Major Branches of Biology

Microbiology: Study of microorganisms, including bacteria, viruses, fungi, and protists.
Botany: Study of plants
Zoology: Study of animals
Ecology: Study of interactions between organisms and their environment
Genetics: Study of heredity and variation
Cell Biology: Study of cells, their structure, and function
Molecular Biology: Focuses on the molecular basis of biological activity.

The Scientific Method

Observation: Scientists begin by observing natural phenomena.
Question: Based on the observation, a question is formulated.
Hypothesis: A proposed explanation is developed to answer the question.
Prediction: Predictions are made based on the hypothesis.
Experimentation: Controlled experiments are conducted to test predictions.
Data Analysis: Data is collected, analyzed, and interpreted.
Conclusion: Results are evaluated and compared with the hypothesis, leading to conclusions and further research possibilities.

Basic Biological Molecules

Carbohydrates: Primary source of energy.
Lipids: Important for storage, structure (membranes), and signaling.
Proteins: Diverse functions including enzymes, structural components, and transport.
Nucleic Acids: DNA and RNA, crucial for the storage and transmission of genetic information.

The Cell- The Fundamental Unit of Life

Prokaryotic Cells: Simple cells, lacking a nucleus and membrane-bound organelles.
Eukaryotic Cells: Complex cells, containing a nucleus and numerous membrane-bound organelles.
Cell membranes: Selective barriers that regulate the passage of substances into and out of the cell.
Cell organelles: Specialized structures within eukaryotic cells with specific functions.

Evolution and Natural Selection

Populations of organisms have changed over vast periods of time.
Organisms can evolve through random changes (mutations) in their genetic makeup.
Natural selection favors traits that enhance survival and reproduction in a given environment.
This leads to the adaptation of species over time.

Biodiversity

The variety of life on Earth, encompassing all organisms from bacteria to plants, fungi, and animals.
Genetic diversity: Differences in genes within a species.
Species diversity: Differences between species in a community.
Ecosystem diversity: Differences in habitats and ecological processes in a region.

Description

This quiz provides an overview of biology, focusing on the characteristics of living organisms. It covers essential concepts such as organization, metabolism, responsiveness, and growth. Explore how these unique traits define life and its processes.