Cell Biology and Genetics Overview

Cell Theory:
- All living organisms are made of cells.
- The cell is the basic unit of life.
- All cells arise from pre-existing cells.
Types of Cells:
- Prokaryotic: No nucleus, smaller, simple structure (e.g., bacteria).
- Eukaryotic: Contains a nucleus, larger, complex structure (e.g., plants, animals).
Cell Organelles:
- Nucleus: Contains genetic material (DNA).
- Mitochondria: Powerhouse of the cell, produces ATP.
- Ribosomes: Sites of protein synthesis.
- Endoplasmic Reticulum (ER):
  - Rough ER: Studded with ribosomes, synthesizes proteins.
  - Smooth ER: Synthesizes lipids and detoxifies drugs.
- Golgi Apparatus: Modifies, sorts, and packages proteins.
- Lysosomes: Contains digestive enzymes to break down waste.

DNA Structure: Double helix made of nucleotides (A, T, C, G).
Gene: Unit of heredity, segment of DNA that codes for a protein.
Chromosomes: Structures made of DNA; humans have 46 (23 pairs).
Mendelian Genetics:
- Dominant vs. Recessive traits.
- Punnett Squares: Tool for predicting genetic outcomes.

Natural Selection: Mechanism of evolution where organisms better adapted to their environment tend to survive and reproduce.
Speciation: Formation of new and distinct species.
Evidence for Evolution:
- Fossil records.
- Comparative anatomy (homologous and analogous structures).
- Molecular biology (DNA comparisons).

Ecosystem: A community of living organisms and their physical environment interacting as a system.
Biomes: Large geographic biotic communities (e.g., rainforest, desert).
Food Chains and Food Webs:
- Producers: Organisms that produce energy (e.g., plants).
- Consumers: Organisms that consume energy (herbivores, carnivores).
- Decomposers: Break down dead material (fungi, bacteria).

Body Systems:
- Circulatory System: Transports blood, nutrients, gases, and wastes.
- Respiratory System: Facilitates gas exchange (oxygen and carbon dioxide).
- Digestive System: Breaks down food into nutrients.
- Nervous System: Controls body functions and responses.
- Endocrine System: Hormonal regulation of body processes.
Homeostasis: Maintenance of stable internal conditions (e.g., temperature, pH).

Photosynthesis: Process by which plants convert light energy into chemical energy (glucose).
Plant Structure:
- Roots: Anchors plant and absorbs water/nutrients.
- Stems: Supports the plant and transports nutrients.
- Leaves: Site of photosynthesis.

Innate vs. Learned Behavior:
- Innate: Instinctual actions (e.g., migration).
- Learned: Acquired through experience (e.g., problem-solving).
Social Structure: Interaction patterns among individuals (e.g., packs, colonies).

Cell Theory: All living organisms consist of cells, which are the basic unit of life, and all cells originate from existing cells.
Prokaryotic cells: Lack a nucleus, are smaller in size, and exhibit a simpler structure; examples include bacteria.
Eukaryotic cells: Possess a nucleus, are larger, and have a more complex structure; examples include plants and animals.
Nucleus: Contains genetic material (DNA) essential for cell function and inheritance.
Mitochondria: Known as the powerhouse of the cell, responsible for ATP production through cellular respiration.
Ribosomes: Sites where protein synthesis occurs, translating genetic information into proteins.
Endoplasmic Reticulum (ER):
- Rough ER: Studded with ribosomes, plays a crucial role in protein synthesis.
- Smooth ER: Involved in lipid synthesis and the detoxification of drugs.
Golgi Apparatus: Modifies, sorts, and packages proteins for secretion or delivery to other organelles.
Lysosomes: Contain digestive enzymes to break down waste materials and cellular debris.

DNA Structure: Comprises a double helix formed from nucleotides (adenine, thymine, cytosine, guanine).
Gene: The fundamental unit of heredity; a segment of DNA that encodes for a specific protein.
Chromosomes: DNA structures within cells; humans have a total of 46 chromosomes organized into 23 pairs.
Mendelian Genetics:
- Dominant vs. Recessive traits determine the expression of characteristics.
- Punnett Squares are utilized to predict the probability of genetic traits in offspring.

Natural Selection: The process whereby organisms better adapted to their environment tend to survive and reproduce more successfully.
Speciation: The evolutionary process by which new and distinct species arise.
Evidence for Evolution:
- Fossil records provide insights into past life forms and their evolution.
- Comparative anatomy reveals similarities and differences among body structures (homologous vs. analogous).
- Molecular biology involves DNA comparisons to trace evolutionary relationships.

Ecosystem: A complex network comprising living organisms and their physical environment, interacting as a system.
Biomes: Large geographic areas with distinct climate and biological communities (e.g., rainforest, desert).
Food Chains and Food Webs:
- Producers: Organisms, such as plants, that produce energy through photosynthesis.
- Consumers: Organisms that rely on others for energy, including herbivores and carnivores.
- Decomposers: Organisms like fungi and bacteria that recycle nutrients by breaking down dead material.

Body Systems:
- Circulatory System: Responsible for transporting blood, nutrients, gases, and waste materials throughout the body.
- Respiratory System: Facilitates the exchange of gases (oxygen and carbon dioxide) between the body and environment.
- Digestive System: Converts food into absorbable nutrients through a series of mechanical and chemical processes.
- Nervous System: Controls and coordinates body functions and responses to stimuli.
- Endocrine System: Manages hormonal regulation of various bodily processes to maintain homeostasis.
Homeostasis: The process of maintaining stable internal conditions, such as temperature and pH, necessary for survival.

Bacteria: Single-celled prokaryotic organisms that can be beneficial (e.g., gut flora) or pathogenic (disease-causing).
Viruses: Acellular entities that cannot reproduce independently; they require a host cell for replication.
Fungi: Eukaryotic organisms that play a key role in the decomposition of organic material and nutrient cycling.

Photosynthesis: The process by which plants transform light energy into chemical energy stored in glucose.
Plant Structure:
- Roots: Anchor the plant and absorb water and nutrients from the soil.
- Stems: Provide structural support and facilitate the transportation of nutrients and water.
- Leaves: Primary site for photosynthesis where light is converted into energy.

Innate Behavior: Instinctual actions that occur naturally in species (e.g., migration patterns).
Learned Behavior: Actions acquired through experience and interaction with the environment (e.g., problem-solving abilities).
Social Structure: The patterns of interaction among individuals within a species, such as packs in wolves or colonies in ants.