Biology Overview

Biology: the scientific study of life and living organisms, including their structure, function, growth, evolution, distribution, and taxonomy.
Scope: biology explores all aspects of life, from molecules and cells to ecosystems and the biosphere.

Botany: study of plants and plant-like organisms.
Zoology: study of animals and animal-like organisms.
Microbiology: study of microorganisms, such as bacteria and viruses.
Ecology: study of interactions between organisms and their environment.
Evolutionary Biology: study of the processes that have shaped the diversity of life on Earth.
Molecular Biology: study of the structure, function, and interactions of biological molecules, such as DNA and proteins.

Cell: the basic structural and functional unit of life.
Cellular components:
- Plasma membrane: outer layer of the cell.
- Cytoplasm: jelly-like substance inside the cell membrane.
- Nucleus: contains DNA, the genetic material.
- Mitochondria: produces energy for the cell.
Cellular processes:
- Metabolism: conversion of energy and nutrients.
- Photosynthesis: process by which plants convert light energy into chemical energy.
- Cell division: process by which cells reproduce.

Genetics: study of heredity and variation.
Key concepts:
- DNA (deoxyribonucleic acid): the molecule that contains genetic information.
- Genes: segments of DNA that code for specific traits.
- Traits: characteristics of an organism determined by genes.
- Inheritance: passing of traits from parents to offspring.

Evolution: change in the characteristics of a population over time.
Key mechanisms:
- Natural selection: process by which populations adapt to their environment.
- Mutation: changes in DNA sequence.
- Genetic drift: random changes in population gene pool.
Evidence for evolution:
- Fossil record: history of life on Earth.
- Comparative anatomy: similarities and differences between organisms.
- Molecular biology: similarities and differences between DNA sequences.

Ecosystem: community of organisms and their environment.
Key concepts:
- Energy flow: transfer of energy from one organism to another.
- Nutrient cycling: circulation of nutrients through the ecosystem.
- Biodiversity: variety of species in an ecosystem.
Ecological interactions:
- Predation: relationship between predator and prey.
- Symbiosis: relationship between two species that benefit each other.
- Competition: relationship between species that compete for resources.

Biology encompasses the scientific study of life, focusing on organisms' structure, function, growth, evolution, distribution, and taxonomy.
It spans various levels of life, from molecular and cellular biology to whole ecosystems and the biosphere.

Botany: Concerned with the study of plants and plant-like organisms.
Zoology: Focuses on the study of animals and animal-like organisms.
Microbiology: Involves the study of microorganisms, including bacteria and viruses.
Ecology: Examines the interactions between organisms and their environmental contexts.
Evolutionary Biology: Investigates the processes that have led to the diversity of life on Earth.
Molecular Biology: Studies the structure, function, and interactions of biological molecules like DNA and proteins.

The cell is recognized as the fundamental structural and functional unit of all living organisms.
Cellular Components:
- Plasma Membrane: Acts as the outer barrier of the cell.
- Cytoplasm: The gel-like substance within the cell that houses organelles.
- Nucleus: Contains DNA, which is the genetic material of the cell.
- Mitochondria: Known as the powerhouse of the cell, responsible for energy production.
Cellular Processes:
- Metabolism: Involves energy conversion and nutrient utilization.
- Photosynthesis: A vital process in plants where light energy is transformed into chemical energy.
- Cell Division: The method through which cells reproduce, essential for growth and repair.

Genetics investigates heredity and the variation observed in organisms.
Key Concepts:
- DNA (Deoxyribonucleic Acid): The molecule that encapsulates genetic instructions.
- Genes: Specific segments of DNA that dictate particular traits of organisms.
- Traits: Observable characteristics influenced by genetic information.
- Inheritance: The process through which traits are passed from parents to their offspring.

Evolution refers to the gradual change in the genetic characteristics of populations over time.
Key Mechanisms:
- Natural Selection: A driving force whereby species adapt to their environments.
- Mutation: Genetic changes in the DNA sequence that introduce variability.
- Genetic Drift: Random changes in the gene pool that can affect population characteristics.
Evidence for Evolution:
- Fossil Record: Provides a historical account of life forms on Earth.
- Comparative Anatomy: Examines anatomical similarities and differences among species.
- Molecular Biology: Analyzes DNA sequence similarities and differences across different organisms.

An ecosystem consists of a community of organisms interacting with their physical environment.
Key Concepts:
- Energy Flow: Describes how energy is transferred through trophic levels within an ecosystem.
- Nutrient Cycling: Explains how nutrients circulate through both biotic and abiotic components.
- Biodiversity: Reflects the variety of species present in a particular ecosystem.
Ecological Interactions:
- Predation: The interaction where one organism (predator) feeds on another (prey).
- Symbiosis: Describes mutually beneficial relationships between different species.
- Competition: Occurs when different species vie for the same resources.