Cell Biology and Genetics Overview

Cell Theory: All living organisms are composed of cells; the cell is 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: Nucleus present, larger, more complex (e.g., plants, animals).
Cell Organelles:
- Nucleus: Contains genetic material (DNA).
- Mitochondria: Energy production (ATP).
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum: Protein and lipid synthesis (Rough ER has ribosomes; Smooth ER does not).
- Golgi Apparatus: Modifies, sorts, and packages proteins and lipids.
- Lysosomes: Digestion and waste removal.

DNA Structure: Double helix composed of nucleotides (adenine, thymine, cytosine, guanine).
Gene Expression: Transcription (DNA to mRNA) and translation (mRNA to protein).
Mendelian Genetics:
- Dominant and recessive traits.
- Punnett squares for predicting genotypes and phenotypes.
Chromosomes: Structures containing DNA; humans have 46 chromosomes (23 pairs).

Natural Selection: Organisms better adapted to their environment tend to survive and reproduce.
Evolutionary Mechanisms:
- Mutation: Changes in DNA sequences.
- Genetic Drift: Random changes in allele frequencies.
- Gene Flow: Transfer of genes between populations.
Speciation: Formation of new and distinct species through evolutionary processes.

Levels of Ecology:
- Organismal: Study of individual organisms.
- Population: Interactions within a group of the same species.
- Community: Interactions among different species.
- Ecosystem: Interaction between living organisms and their environment.
Biomes: Large ecological areas (e.g., deserts, forests, tundras) characterized by specific climates and organisms.
Food Chains/Webs: Energy flow through trophic levels (producers, consumers, decomposers).

Homeostasis: Maintenance of stable internal conditions (e.g., temperature, pH).
Organ Systems:
- Circulatory: Transports blood, nutrients, gases.
- Respiratory: Gas exchange (oxygen and carbon dioxide).
- Digestive: Breaks down food, absorbs nutrients.
- Nervous: Communicates signals; controls body functions.
Hormonal Regulation: Endocrine system regulates physiological processes through hormones.

Photosynthesis: Process by which plants convert light energy into chemical energy (glucose) using chlorophyll in chloroplasts.
Plant Structure:
- Roots: Absorb water and nutrients.
- Stems: Support and transport.
- Leaves: Main site of photosynthesis.
Reproductive Strategies: Sexual (flowers, seeds) vs. asexual (cuttings, runners).

Bacteria: Prokaryotic organisms; can be beneficial (gut flora) or pathogenic.
Viruses: Non-cellular entities that require a host to replicate.
Fungi: Decomposers; includes yeasts and molds.

Macromolecules:
- Proteins: Chains of amino acids; essential for structure and function.
- Carbohydrates: Sugars; primary energy source.
- Lipids: Fats; involved in energy storage and cell membranes.
- Nucleic Acids: DNA and RNA; carry genetic information.

Cell Theory: Defines that all life forms are made up of cells, which serve as the fundamental units of life, and that cells originate from existing cells.
Prokaryotic Cells: Characterized by the absence of a nucleus, these smaller and simpler cells include organisms such as bacteria.
Eukaryotic Cells: Possess a nucleus and are larger and more complex, encompassing plant and animal cells.
Cell Organelles:
- Nucleus: Houses genetic material (DNA).
- Mitochondria: Responsible for ATP production, serving as the cell's energy powerhouse.
- Ribosomes: Sites for protein synthesis.
- Endoplasmic Reticulum (ER): Divided into Rough ER, which has ribosomes for protein synthesis, and Smooth ER, which is involved in lipid synthesis.
- Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.
- Lysosomes: Contains digestive enzymes for waste breakdown and removal.

DNA Structure: Composed of a double helix of nucleotides, which include adenine, thymine, cytosine, and guanine.
Gene Expression: Involves transcription (process of converting DNA into mRNA) and translation (converting mRNA into proteins).
Mendelian Genetics: Basis for understanding inheritance patterns; dominant and recessive traits can be analyzed using Punnett squares to predict genotypes and phenotypes.
Chromosomes: DNA is organized into structures called chromosomes; human cells contain 46 chromosomes, arranged in 23 pairs.

Natural Selection: Describes the process where organisms better suited to their environment have increased survival and reproductive success.
Evolutionary Mechanisms:
- Mutation: Changes in DNA that can lead to new traits.
- Genetic Drift: Random fluctuations in allele frequencies within a population.
- Gene Flow: Movement of genes between populations, affecting genetic diversity.
Speciation: The process through which new and distinct species arise from evolutionary changes.

Levels of Ecology:
- Organismal: Focuses on individual organisms.
- Population: Studies interactions among individuals of the same species.
- Community: Explores interactions among different species.
- Ecosystem: Examines the connections between living organisms and their physical environments.
Biomes: Large regions characterized by specific climatic conditions and biological communities, such as deserts, forests, and tundras.
Food Chains/Webs: Models showing the flow of energy through various trophic levels, consisting of producers, consumers, and decomposers.

Homeostasis: The process of maintaining stable internal conditions like temperature and pH levels.
Organ Systems:
- Circulatory System: Distributes blood, nutrients, and gases throughout the body.
- Respiratory System: Facilitates the exchange of oxygen and carbon dioxide.
- Digestive System: Breaks down food and absorbs essential nutrients.
- Nervous System: Transmits signals to control bodily functions.
Hormonal Regulation: The endocrine system utilizes hormones to regulate various physiological processes.

Photosynthesis: The biochemical process that enables plants to convert light energy into glucose using chlorophyll in chloroplasts.
Plant Structure:
- Roots: Functions include absorption of water and nutrients from the soil.
- Stems: Provide structural support and facilitate the transport of nutrients and water.
- Leaves: Primary site for photosynthesis.
Reproductive Strategies: Involves modes such as sexual reproduction (via flowers and seeds) and asexual reproduction (e.g., through cuttings or runners).

Bacteria: Diverse prokaryotic organisms that can be beneficial (like gut microbiota) or pathogenic.
Viruses: Non-cellular entities that require a host cell for replication and cannot survive independently.
Fungi: Comprising decomposers, includes various forms like yeasts and molds essential for nutrient recycling in ecosystems.

Macromolecules:
- Proteins: Formed from amino acids and are crucial for cellular structure and function.
- Carbohydrates: Sugars that serve as the primary source of energy for cells.
- Lipids: Fats that play vital roles in energy storage and forming cell membranes.
- Nucleic Acids: DNA and RNA which store and transmit genetic information.