Cell Biology Basics

Cell Structure:
- Plasma membrane: semi-permeable membrane that separates cell from environment
- Cytoplasm: jelly-like substance where metabolic processes occur
- Nucleus: contains genetic material (DNA)
- Mitochondria: site of cellular respiration
- Endoplasmic reticulum (ER): involved in protein synthesis and transport
- Ribosomes: site of protein synthesis
Cellular Processes:
- Photosynthesis: light-dependent reaction that produces glucose
- Cellular respiration: process of generating energy from glucose
- Mitosis: cell division that produces two identical daughter cells
- Meiosis: cell division that produces four non-identical daughter cells (gametes)

DNA Structure:
- Double helix model: two complementary strands of nucleotides
- Nucleotides: A, C, G, and T (adenine, cytosine, guanine, and thymine)
Genetic Inheritance:
- Mendel's laws: principles of inheritance (segregation, independent assortment, and dominance)
- Genotype: genetic makeup of an individual
- Phenotype: physical expression of genotype
- Dominant and recessive alleles: types of alleles that influence phenotype
Genetic Variation:
- Mutation: change in DNA sequence
- Genetic drift: random change in allele frequency
- Gene flow: movement of genes from one population to another

Ecosystems:
- Biotic factors: living components (organisms, populations, communities)
- Abiotic factors: non-living components (light, temperature, water, etc.)
- Energy flow: producers (autotrophs) → consumers (heterotrophs) → decomposers
Population Ecology:
- Population growth: influenced by birth rate, death rate, and migration
- Carrying capacity: maximum population size supported by environment
- Population dynamics: changes in population size over time
Community Ecology:
- Species interactions: competition, predation, symbiosis, and mutualism
- Niche: unique role of a species in an ecosystem

Mechanisms of Evolution:
- Natural selection: adaptation to environment through differential reproduction
- Genetic drift: random change in allele frequency
- Mutation: change in DNA sequence
- Gene flow: movement of genes from one population to another
Evidence for Evolution:
- Fossil record: chronological record of ancient organisms
- Comparative anatomy: similarities and differences between body structures
- Molecular biology: similarity in DNA and protein sequences
Speciation:
- Allopatric speciation: geographic isolation leads to new species
- Sympatric speciation: reproductive isolation within a population

Homeostasis:
- Maintenance of internal environment despite external changes
- Negative feedback mechanisms: regulation of physiological processes
Nervous System:
- Central nervous system (CNS): brain and spinal cord
- Peripheral nervous system (PNS): nerves and ganglia
- Neurons: basic units of nervous system
Circulatory System:
- Heart: pumps blood throughout body
- Blood vessels: arteries, veins, and capillaries
- Blood: transports oxygen, nutrients, and waste products

Cell Structure:
- Plasma membrane separates cell from environment and regulates what enters and leaves the cell
- Cytoplasm is the site of many metabolic processes, including glycolysis and protein synthesis
- Nucleus is the control center of the cell, containing genetic material (DNA)
- Mitochondria generate energy for the cell through cellular respiration
- Endoplasmic reticulum (ER) plays a critical role in protein synthesis and transport
- Ribosomes are the site of protein synthesis, reading mRNA to build proteins
Cellular Processes:
- Photosynthesis uses light energy to produce glucose
- Cellular respiration generates energy from glucose
- Mitosis produces two identical daughter cells through cell division
- Meiosis produces four non-identical daughter cells (gametes) through cell division

DNA Structure:
- Double helix model consists of two complementary strands of nucleotides
- Nucleotides are the building blocks of DNA, with four main types: A, C, G, and T
Genetic Inheritance:
- Mendel's laws describe the principles of inheritance, including segregation, independent assortment, and dominance
- Genotype is the genetic makeup of an individual
- Phenotype is the physical expression of genotype
- Dominant and recessive alleles influence phenotype
Genetic Variation:
- Mutation is a change in DNA sequence
- Genetic drift is a random change in allele frequency
- Gene flow is the movement of genes from one population to another

Ecosystems:
- Biotic factors include living components such as organisms, populations, and communities
- Abiotic factors include non-living components such as light, temperature, and water
- Energy flows from producers (autotrophs) to consumers (heterotrophs) to decomposers
Population Ecology:
- Population growth is influenced by birth rate, death rate, and migration
- Carrying capacity is the maximum population size supported by the environment
- Population dynamics describe changes in population size over time
Community Ecology:
- Species interactions include competition, predation, symbiosis, and mutualism
- Niche is the unique role of a species in an ecosystem

Mechanisms of Evolution:
- Natural selection is the process of adaptation to the environment through differential reproduction
- Genetic drift is a random change in allele frequency
- Mutation is a change in DNA sequence
- Gene flow is the movement of genes from one population to another
Evidence for Evolution:
- Fossil record provides a chronological record of ancient organisms
- Comparative anatomy highlights similarities and differences between body structures
- Molecular biology shows similarities in DNA and protein sequences
Speciation:
- Allopatric speciation occurs through geographic isolation
- Sympatric speciation occurs through reproductive isolation within a population

Homeostasis:
- Maintenance of internal environment despite external changes
- Negative feedback mechanisms regulate physiological processes
Nervous System:
- Central nervous system (CNS) consists of the brain and spinal cord
- Peripheral nervous system (PNS) consists of nerves and ganglia
- Neurons are the basic units of the nervous system
Circulatory System:
- Heart pumps blood throughout the body
- Blood vessels include arteries, veins, and capillaries
- Blood transports oxygen, nutrients, and waste products