Fundamental Concepts in Biology

Cell Theory
- All living organisms are composed of cells.
- The cell is the basic unit of life.
- All cells come from pre-existing cells.
Basic Units of Life
- Prokaryotic Cells: Lack a nucleus and membrane-bound organelles.
- Eukaryotic Cells: Contain a nucleus and organelles (e.g., animals, plants, fungi).
Genetics
- DNA Structure: Double helix formed by nucleotides (adenine, thymine, cytosine, guanine).
- Gene Expression: Process by which information from a gene is used to synthesize functional gene products (proteins).
- Mendelian Genetics: Principles of inheritance first described by Gregor Mendel, including laws of segregation and independent assortment.
Evolution
- Natural Selection: Mechanism of evolution where organisms better adapted to their environment tend to survive and produce more offspring.
- Mutation: Change in DNA sequence that can lead to variation and may be beneficial, neutral, or harmful.
Ecology
- Ecosystems: Interactions among organisms and their environment, including biotic (living) and abiotic (non-living) factors.
- Food Chains/Webs: Represent the flow of energy through an ecosystem, starting from producers to various levels of consumers.
Physiology
- Study of the functions of living organisms and their parts, examining processes like circulation, respiration, and digestion.
- Homeostasis: The process through which organisms maintain stable internal conditions.
Plant Biology
- Photosynthesis: Process by which plants convert light energy into chemical energy (glucose) using chlorophyll.
- Plant Structures: Roots (absorb water/nutrients), stems (support), and leaves (photosynthesis).
Animal Biology
- Animal Systems: Integumentary, muscular, skeletal, circulatory, respiratory, digestive, excretory, nervous, endocrine, and reproductive systems.
- Behavioral Adaptations: Instincts and learned behaviors that enhance survival and reproduction.
Microbiology
- Study of microorganisms including bacteria, viruses, fungi, and protozoa.
- Role in diseases, fermentation, decomposition, and nitrogen fixation.

Key Processes in Biology

Metabolism
- Sum of all biochemical reactions in an organism, including catabolism (breaking down) and anabolism (building up).
Cell Division
- Mitosis: Division of a single cell into two identical daughter cells.
- Meiosis: Process that produces gametes (sperm and eggs) with half the number of chromosomes.
Symbiosis
- Mutualism: Both species benefit (e.g., bees and flowers).
- Commensalism: One species benefits, the other is unaffected (e.g., barnacles on whales).
- Parasitism: One species benefits at the expense of another (e.g., ticks on mammals).

Important Techniques in Biology

Microscopy: Use of microscopes to observe small biological samples.
Gel Electrophoresis: Technique for separating DNA, RNA, or proteins based on size.
PCR (Polymerase Chain Reaction): Method to amplify DNA sequences for analysis.
CRISPR: A technology for editing genes by adding, removing, or altering DNA sequences.

Branches of Biology

Molecular Biology: Study of biological processes at the molecular level.
Biochemistry: Chemistry of living organisms and their components.
Cell Biology: Study of cell structure, function, and behavior.
Ecology: Study of interactions between organisms and their environment.
Evolutionary Biology: Study of the origins and changes in the diversity of life.
Zoology: Study of animals.
Botany: Study of plants.
Microbiology: Study of microorganisms.
Genetics: Study of heredity and variation in organisms.

Cell Theory

All living things are made of cells.
Cells are the basic building blocks of life.
New cells are always formed from existing cells.
Prokaryotic cells lack a nucleus and membrane-bound organelles.
Eukaryotic cells have a nucleus and membrane-bound organelles, like animals, plants, and fungi.

Genetics

DNA is a double helix composed of four nucleotides: adenine, thymine, cytosine, and guanine.
Gene expression uses the information in a gene to create functional products, primarily proteins.
Mendelian genetics describes the fundamental principles of inheritance, including the laws of segregation and independent assortment, as explained by Gregor Mendel.

Evolution

Natural selection is the process where organisms better adapted to their environment survive and reproduce more offspring.
Mutations are changes in DNA sequence that can introduce variation and be beneficial, neutral, or harmful.

Ecology

Ecosystems involve interactions between organisms and their environment, including biotic (living) and abiotic (non-living) factors.
Food chains/webs illustrate the flow of energy through an ecosystem, starting from producers and moving through various consumer levels.

Physiology

Physiology is the study of how living organisms and their parts function, including processes like circulation, respiration, and digestion.
Homeostasis is the process of maintaining stable internal conditions in organisms.

Plant Biology

Photosynthesis is the process plants use to convert light energy into chemical energy in the form of glucose, using chlorophyll.
Plant structures include roots (absorbing water and nutrients), stems (support), and leaves (photosynthesis).

Animal Biology

Animal systems include integumentary, muscular, skeletal, circulatory, respiratory, digestive, excretory, nervous, endocrine, and reproductive systems.
Behavioral adaptations include instincts and learned behaviors that improve survival and reproduction.

Microbiology

Microbiology is the study of microorganisms, including bacteria, viruses, fungi, and protozoa.
Microorganisms play important roles in diseases, fermentation, decomposition, and nitrogen fixation.

Key Processes in Biology

Metabolism encompasses all the biochemical reactions occurring in an organism, including catabolism (breaking down) and anabolism (building up).
Cell division includes mitosis (creating two identical daughter cells from a single cell) and meiosis (producing gametes (sperm and eggs) with half the number of chromosomes).
Symbiosis includes mutualism (both species benefit), commensalism (one benefits, the other is unaffected), and parasitism (one species benefits at the expense of the other).

Important Techniques in Biology

Microscopy is the use of microscopes to observe small biological samples.
Gel electrophoresis is a technique used to separate DNA, RNA, or proteins based on their size.
PCR (polymerase chain reaction) is a method of amplifying DNA sequences for analysis.
CRISPR is a technology used for editing genes by adding, removing, or modifying DNA sequences.

Branches of Biology

Molecular Biology studies biological processes at the molecular level.
Biochemistry focuses on the chemistry of living organisms and their components.
Cell Biology studies the structure, function, and behavior of cells.
Ecology studies the interactions between organisms and their environment.
Evolutionary Biology examines the origins and changes in the diversity of life.
Zoology is the study of animals.
Botany is the study of plants.
Microbiology is the study of microorganisms.
Genetics is the study of heredity and variation in organisms.