Cell Structure and Functions

Cell Structure:
- Plasma membrane: semipermeable membrane that separates cell from environment
- Cytoplasm: jelly-like substance inside cell where metabolic processes occur
- Nucleus: control center of cell where DNA is stored
- Mitochondria: organelles responsible for energy production (cellular respiration)
- Ribosomes: site of protein synthesis
Cell Functions:
- Metabolism: conversion of energy and nutrients
- Growth and Development: cell division and differentiation
- Response to Stimuli: cells can respond to environmental stimuli
- Reproduction: cells can reproduce themselves

Key Principles:
- Descent with modification: all species share a common ancestor
- Variation and mutation: genetic changes occur in populations
- Natural selection: environment selects for advantageous traits
- Speciation: formation of new species
Evidence for Evolution:
- Fossil record: fossilized remains of ancient organisms
- Comparative anatomy: similar structures in different species
- Molecular biology: similarities in DNA and protein sequences
- Biogeography: geographic distribution of species

Types of Microorganisms:
- Bacteria: prokaryotic cells, single-celled organisms
- Viruses: non-living particles that replicate inside host cells
- Fungi: eukaryotic cells, including mushrooms and yeasts
- Protists: eukaryotic cells, including protozoa and algae
Microbial Interactions:
- Symbiosis: mutualistic, commensal, or parasitic relationships
- Pathogenesis: microorganisms cause disease in hosts
- Decomposition: microorganisms break down organic matter

Ecosystem Components:
- Biotic factors: living organisms (plants, animals, microorganisms)
- Abiotic factors: non-living environment (light, temperature, water, etc.)
Ecological Relationships:
- Predator-prey: predator feeds on prey
- Competition: organisms compete for resources
- Symbiosis: mutualistic, commensal, or parasitic relationships
Ecosystem Processes:
- Energy flow: energy transferred from one trophic level to another
- Nutrient cycling: nutrients are recycled through ecosystem

Mendelian Genetics:
- Laws of inheritance: segregation, independent assortment, and dominance
- Genotype: genetic makeup of an individual
- Phenotype: physical expression of genotype
Molecular Genetics:
- DNA structure: double helix with nucleotide bases
- Gene expression: transcription and translation of DNA
- Genetic mutations: changes in DNA sequence
Genetic Variation:
- Genetic drift: random change in gene frequency
- Gene flow: movement of genes between populations
- Mutation: change in DNA sequence

Plasma membrane is a semipermeable membrane that separates the cell from its environment
Cytoplasm is a jelly-like substance inside the cell where metabolic processes occur
Nucleus is the control center of the cell where DNA is stored
Mitochondria are organelles responsible for energy production through cellular respiration
Ribosomes are the site of protein synthesis
Metabolic processes involve the conversion of energy and nutrients
Cell growth and development involve cell division and differentiation
Cells can respond to environmental stimuli and reproduce themselves

Descent with modification is the principle that all species share a common ancestor
Variation and mutation occur in populations through genetic changes
Natural selection selects for advantageous traits in a population
Speciation occurs when a new species is formed
Fossil record provides evidence of evolution through fossilized remains of ancient organisms
Comparative anatomy shows similar structures in different species
Molecular biology reveals similarities in DNA and protein sequences
Biogeography shows the geographic distribution of species

Biotic factors include living organisms such as plants, animals, and microorganisms
Abiotic factors include non-living environment such as light, temperature, water, etc.
Predator-prey relationships involve one species feeding on another
Competition occurs when organisms compete for resources
Symbiosis can be mutualistic, commensal, or parasitic relationships
Energy flow is transferred from one trophic level to another
Nutrient cycling involves the recycling of nutrients through the ecosystem