Introduction to Biology

Biology is the scientific study of life and living organisms
It involves the study of structure, function, growth, evolution, distribution, and taxonomy of all living things

Botany: study of plants
Zoology: study of animals
Microbiology: study of microorganisms
Ecology: study of interactions between organisms and their environment
Genetics: study of heredity and variation
Biochemistry: study of chemical processes in living organisms
Molecular Biology: study of biological molecules and their interactions
Evolutionary Biology: study of the processes that have shaped the diversity of life on Earth

Cells are the basic units of life
Cell structure:
- Plasma membrane: outer layer of cell
- Cytoplasm: jelly-like substance inside cell
- Nucleus: control center of cell
- Mitochondria: energy-producing structures
- Ribosomes: protein synthesis sites
Cell functions:
- Metabolism: energy production and consumption
- Photosynthesis: conversion of light energy into chemical energy
- Cell division: process of cell growth and reproduction

Heredity: passing of traits from parents to offspring
Genes: units of heredity made up of DNA
DNA: double-stranded molecule containing genetic information
Chromosomes: thread-like structures carrying genes
Inheritance patterns:
- Dominant and recessive traits
- Punnett squares: predicting offspring traits

Theory of Evolution: all living organisms share a common ancestor
Mechanisms of evolution:
- Natural selection: survival and reproduction of fittest individuals
- Mutation: changes in DNA sequence
- Genetic drift: random changes in gene pool
Evidence for evolution:
- Fossil record: history of life on Earth
- Comparative anatomy: similarities and differences between species
- Molecular biology: similarities in DNA and protein sequences

Study of interactions between organisms and their environment
Ecosystems: communities of living and non-living components
Energy flow:
- Producers: organisms that make their own food
- Consumers: organisms that obtain energy by consuming other organisms
- Decomposers: organisms that break down dead organic matter
Population dynamics:
- Growth and decline of populations
- Factors affecting population growth: birth rate, death rate, migration

Biology studies life, focusing on living organisms' structure, function, growth, evolution, distribution, and classification.

Botany: Involves the systematic study of plant life.
Zoology: Concentrates on animal life and behaviors.
Microbiology: Examines microorganisms like bacteria and viruses.
Ecology: Investigates relationships among organisms and their environment.
Genetics: Focuses on heredity, genetic variation, and DNA.
Biochemistry: Studies the chemical processes that sustain life.
Molecular Biology: Researches biological molecules and their functions.
Evolutionary Biology: Explores the processes influencing the diversity of life.

Cells function as the fundamental units of life.
Cell Structure:
- Plasma membrane: Protective outer boundary of the cell.
- Cytoplasm: Gel-like substance where cellular processes occur.
- Nucleus: Contains genetic material and regulates cell activities.
- Mitochondria: Sites of cellular respiration, providing energy.
- Ribosomes: Locations for protein synthesis.
Cell Functions:
- Metabolism: Encompasses all chemical reactions for energy management.
- Photosynthesis: Process by which light energy is converted into chemical energy in plants.
- Cell Division: Mechanism for growth and reproduction, including mitosis and meiosis.

Heredity: Transmission of physical and genetic traits from parents to offspring.
Genes: Fundamental units containing DNA that determine traits.
DNA: Double-helix structure housing genetic information vital for cell functions.
Chromosomes: Structures that organize and carry genes in a living organism.
Inheritance Patterns:
- Dominant traits: Only one copy needed for expression.
- Recessive traits: Require two copies for expression.
- Punnett Squares: Tools for predicting offspring trait combinations.

Theory of Evolution: Proposes that all living organisms evolve from a common ancestor over time.
Mechanisms of Evolution:
- Natural Selection: Process where advantageous traits become more common.
- Mutation: Random genetic changes that can lead to new traits.
- Genetic Drift: Random fluctuations in allele frequencies that can affect populations.
Evidence for Evolution:
- Fossil Record: Documents the existence and changes in species over geological time.
- Comparative Anatomy: Studies structural similarities and differences to infer evolutionary relationships.
- Molecular Biology: Analyzes genetic similarities to understand evolutionary links.

Ecology: Focuses on the relationships between organisms and their environments.
Ecosystems: Complex networks of biotic (living) and abiotic (non-living) components.
Energy Flow:
- Producers: Autotrophic organisms that generate energy via photosynthesis.
- Consumers: Heterotrophic organisms that derive energy from consuming others.
- Decomposers: Organisms that recycle nutrients by breaking down dead matter.
Population Dynamics:
- Involves studying the population changes influenced by birth rates, death rates, and migration patterns.