Cell Biology and Genetics Overview

Cell Biology

Cell Theory: All living organisms are composed of cells; cells are the basic unit of life; all cells arise from pre-existing cells.
Prokaryotic vs. Eukaryotic Cells:
- Prokaryotic: No nucleus, smaller, simpler (e.g., bacteria).
- Eukaryotic: Have a nucleus, larger, more complex (e.g., plants, animals).
Organelles:
- Mitochondria: Powerhouse of the cell, energy production.
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum (ER): Protein and lipid synthesis (Rough ER = ribosomes; Smooth ER = no ribosomes).
- Golgi Apparatus: Modifies, sorts, and packages proteins.
- Lysosomes: Digestion and waste removal.

Genetics

DNA Structure: Double helix composed of nucleotides (adenine, thymine, cytosine, guanine).
Gene: A segment of DNA that codes for a protein.
Mendelian Genetics:
- Laws of Segregation: Alleles separate during gamete formation.
- Laws of Independent Assortment: Genes for different traits can segregate independently.
Mutations: Changes in DNA sequence, can be beneficial, neutral, or harmful.

Evolution

Natural Selection: Process where organisms better adapted to their environment tend to survive and produce more offspring.
Speciation: Formation of new and distinct species in the course of evolution.
Evidence of Evolution:
- Fossil records: Show changes over time.
- Comparative anatomy: Homologous structures indicate common ancestry.
- Molecular biology: Genetic similarities among species.

Ecology

Ecosystems: Communities of living organisms and their physical environment interacting as a system.
Biomes: Large ecological areas (e.g., forests, deserts) defined by climate, soil, and vegetation.
Food Chains and Webs:
- Producers (autotrophs) → Consumers (heterotrophs) → Decomposers.
Ecological Pyramids: Show energy flow (energy pyramid), biomass (biomass pyramid), and numbers (pyramid of numbers).

Physiology

Homeostasis: Maintenance of stable internal conditions (e.g., temperature, pH).
Organ Systems:
- Circulatory System: Transports blood, nutrients, gases.
- Respiratory System: Exchange of gases (oxygen and carbon dioxide).
- Nervous System: Controls body activities and responses.
- Endocrine System: Hormonal regulation of bodily functions.

Plant Biology

Photosynthesis: Process by which plants convert sunlight, water, and CO2 into glucose and oxygen.
Plant Structure:
- Roots: Absorb water and nutrients.
- Stems: Support and transport.
- Leaves: Primary site for photosynthesis.
Reproductive Strategies:
- Sexual reproduction involves flowers, seeds, and fruit.
- Asexual reproduction includes methods like budding and fragmentation.

Animal Behavior

Innate Behavior: Instinctive, genetically inherited (e.g., reflexes).
Learned Behavior: Acquired through experience (e.g., conditioning).
Social Behavior: Interactions among individuals (e.g., cooperation, competition).

Microbiology

Bacteria: Unicellular prokaryotes, can be beneficial or pathogenic.
Viruses: Acellular, need a host to replicate; not considered living organisms.
Fungi: Eukaryotic organisms that decompose organic material, can be unicellular (yeasts) or multicellular (molds, mushrooms).

Biotechnology

Genetic Engineering: Modification of organisms' DNA to produce desired traits (e.g., GMOs).
CRISPR: A tool for editing genes with precision.
Cloning: Producing a genetically identical copy of an organism.

Conservation Biology

Biodiversity: Variety of life in the world or a particular habitat.
Endangered Species: Species at risk of extinction due to habitat loss, pollution, overfishing, etc.
Conservation Strategies: Protected areas, wildlife corridors, and sustainable practices.

Cell Biology

Cell Theory: All life forms consist of cells; cells serve as the foundational unit of life; all cells originate from existing cells.
Prokaryotic Cells: Characterized by the absence of a nucleus; typically smaller and less complex (e.g., bacteria).
Eukaryotic Cells: Contain a nucleus; larger and more intricate (e.g., plant and animal cells).
Mitochondria: Known as the powerhouse of the cell, responsible for energy production through cellular respiration.
Ribosomes: Essential for protein synthesis, translating RNA into proteins.
Endoplasmic Reticulum (ER): Involved in the synthesis of proteins and lipids; Rough ER has ribosomes, while Smooth ER does not.
Golgi Apparatus: Modifies, sorts, and packages proteins for secretion or delivery within the cell.
Lysosomes: Contains digestive enzymes for breaking down waste materials and cellular debris.

Genetics

DNA Structure: Composed of a double helix formed by nucleotides: adenine (A), thymine (T), cytosine (C), guanine (G).
Genes: Segments of DNA that encode instructions for building proteins.
Mendelian Genetics:
- Laws of Segregation: States that allele pairs separate during gamete formation.
- Laws of Independent Assortment: Suggests that genes for different traits can segregate independently during gamete formation.
Mutations: Alterations in DNA sequences that can be beneficial, neutral, or detrimental to an organism.

Evolution

Natural Selection: Mechanism of evolution where organisms better suited to their environment tend to survive and reproduce more successfully.
Speciation: The evolutionary process by which new species arise.
Evidence of Evolution:
- Fossil Records: Document changes in species over geological time.
- Comparative Anatomy: Presence of homologous structures among different species indicates common ancestry.
- Molecular Biology: Genetic similarities and differences help trace evolutionary relationships among species.

Ecology

Ecosystems: Consist of interactions between living organisms and their physical surroundings, functioning as a self-regulating system.
Biomes: Large ecological areas characterized by specific climate conditions, soil types, and vegetation types (e.g., forests, deserts).
Food Chains and Webs:
- Producers (Autotrophs): Create their own food through photosynthesis.
- Consumers (Heterotrophs): Rely on other organisms for food.
- Decomposers: Break down dead organic material, returning nutrients to the ecosystem.
Ecological Pyramids: Visual representations of energy flow (energy pyramid), biomass distribution (biomass pyramid), and organism numbers (pyramid of numbers).

Physiology

Homeostasis: The ability of organisms to maintain stable internal conditions despite external changes (e.g., temperature regulation).
Organ Systems:
- Circulatory System: Facilitates transport of blood, nutrients, and gases throughout the body.
- Respiratory System: Responsible for the exchange of gases, primarily oxygen and carbon dioxide.
- Nervous System: Regulates body functions and responses through signals and coordination.
- Endocrine System: Governs bodily functions via hormones, influencing growth, metabolism, and stress responses.

Plant Biology

Photosynthesis: The process where plants convert sunlight, water, and carbon dioxide into glucose and oxygen, vital for energy.
Plant Structure:
- Roots: Anchor the plant and absorb water plus nutrients from the soil.
- Stems: Provide support and facilitate transport of nutrients and water.
- Leaves: Primary location for photosynthesis due to their broad surface area.
Reproductive Strategies:
- Sexual Reproduction: Involves flowers, seeds, and fruits for reproduction.
- Asexual Reproduction: Includes methods like budding and fragmentation.

Animal Behavior

Innate Behavior: Behaviors that an organism is born with, influenced by genetics (e.g., reflexes).
Learned Behavior: Behaviors acquired through experience and environmental interaction (e.g., conditioning).
Social Behavior: Interactions among individuals in a species, including cooperation and competition.

Microbiology

Bacteria: Single-celled prokaryotic organisms, which can be either beneficial (e.g., gut flora) or pathogenic (causing diseases).
Viruses: Acellular entities that require a host cell to replicate and do not exhibit characteristics of living organisms.
Fungi: Eukaryotic decomposers that can be unicellular (yeasts) or multicellular (molds, mushrooms) and play an essential role in nutrient cycling.

Biotechnology

Genetic Engineering: Manipulation of an organism's DNA to produce desirable traits, such as genetically modified organisms (GMOs).
CRISPR: A cutting-edge tool for precise gene editing that allows modification of DNA sequences in living organisms.
Cloning: Creating an organism that is genetically identical to another, often done through somatic cell nuclear transfer.

Conservation Biology

Biodiversity: Refers to the variety of life in a given habitat or across the planet, crucial for ecosystem resilience.
Endangered Species: Species that face a high risk of extinction due to factors such as habitat destruction, pollution, or overfishing.
Conservation Strategies: Methods to protect biodiversity, including establishing protected areas, creating wildlife corridors, and promoting sustainable practices.