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.
Cell Organelles:
- Nucleus: Contains genetic material (DNA).
- Mitochondria: Powerhouse of the cell, site of ATP production.
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum: Rough ER (protein synthesis), Smooth ER (lipid synthesis).
- Golgi Apparatus: Modifies and packages proteins.
- Lysosomes: Digestion of waste materials.
- Plasma Membrane: Bi-layer that controls entry and exit of substances.

DNA Structure: Double helix formed by nucleotides (A, T, C, G).
Gene: A segment of DNA that codes for a protein.
Mendelian Genetics:
- Dominant and Recessive Traits: Dominant alleles mask the effect of recessive alleles.
- Punnett Squares: Used to predict offspring genotypes.
Chromosomes: Humans have 23 pairs; one from each parent.

Natural Selection: Survival of the fittest; organisms best adapted to their environment survive and reproduce.
Mutation: Changes in DNA sequences that can lead to diversity.
Speciation: Formation of new and distinct species through evolution.

Ecosystem: Community of living organisms and their physical environment interacting as a system.
Biomes: Large ecological areas (e.g., tundra, rainforest) characterized by specific climates and organisms.
Food Chains and Webs: Shows energy transfer in ecosystems; producers to consumers to decomposers.

Homeostasis: The maintenance of stable internal conditions in an organism.
Organ Systems:
- Circulatory System: Transports blood and nutrients.
- Respiratory System: Gas exchange (O2 in, CO2 out).
- Digestive System: Breakdown of food, absorption of nutrients.
- Nervous System: Controls and coordinates body activities.

Photosynthesis: Process by which plants convert sunlight into chemical energy (glucose).
Plant Structures:
- Roots: Absorb water and nutrients.
- Stems: Support and transport.
- Leaves: Main site of photosynthesis.
Reproduction:
- Pollination: Transfer of pollen from male to female structures.
- Seed Dispersal: Mechanisms for spreading seeds (wind, water, animals).

Types of Microorganisms:
- Bacteria: Single-celled organisms, can be beneficial or pathogenic.
- Viruses: Non-living infectious agents that require a host to replicate.
- Fungi: Decomposers, can be multi-cellular (mushrooms) or unicellular (yeasts).

Macromolecules:
- Carbohydrates: Energy source (sugars, starches).
- Proteins: Made of amino acids, perform various functions.
- Lipids: Fats and oils, components of cell membranes, energy storage.
- Nucleic Acids: DNA and RNA, genetic information carriers.

Anatomy: Study of the structure of the human body.
Physiology: Study of functions and processes of the body systems.
Immune System: Defends against infections; includes innate and adaptive responses.
Hormonal Regulation: Hormones control many body functions (e.g., metabolism, growth).

Cell Theory emphasizes that all living things are composed of cells, the cell is the fundamental unit of life, and all cells arise from pre-existing cells.
Cell Organelles are specialized structures within a cell that perform specific functions.
- Nucleus contains genetic material (DNA), controlling the cell's activities.
- Mitochondria are the powerhouse of the cell, responsible for ATP production.
- Ribosomes are involved in protein synthesis.
- Endoplasmic Reticulum (ER) exists in two forms: rough ER (protein synthesis) and smooth ER (lipid synthesis).
- Golgi Apparatus modifies and packages proteins for transport within or outside the cell.
- Lysosomes digest waste materials within the cell.
- Plasma Membrane is a bilayer that regulates the movement of substances into and out of the cell.

DNA Structure is a double helix formed by nucleotides (adenine (A), thymine (T), cytosine (C), and guanine (G)).
A gene is a segment of DNA that codes for a specific protein.
Mendelian Genetics explains inheritance patterns.
- Dominant and Recessive Traits: Dominant alleles mask the effect of recessive alleles.
- Punnett Squares are diagrams used to predict offspring genotypes.
- Humans have 23 pairs of chromosomes, one from each parent.

Natural Selection is the process where organisms best suited to their environment survive and reproduce more successfully.
Mutation refers to changes in DNA sequences, contributing to genetic diversity.
Speciation is the evolutionary process where new and separate species arise.

An ecosystem is a community of living organisms and their physical environment interacting as a system.
Biomes are large ecological areas characterized by specific climates and organisms (e.g., tundra, rainforest).
Food Chains and Webs illustrate energy transfer in ecosystems, from producers (plants) to consumers (animals) to decomposers (bacteria and fungi).

Homeostasis refers to the maintenance of stable internal conditions in an organism.
Organ Systems are groups of organs working together to perform a specific function.
- Circulatory System transports blood and nutrients throughout the body.
- Respiratory System facilitates gas exchange (oxygen in, carbon dioxide out).
- Digestive System breaks down food and absorbs nutrients.
- Nervous System controls and coordinates body activities.

Photosynthesis is the process by which plants convert sunlight into chemical energy (glucose).
Plant Structures are adapted for specific functions:
- Roots absorb water and nutrients.
- Stems provide support and transport.
- Leaves are the primary sites of photosynthesis.
Plant Reproduction involves:
- Pollination - transfer of pollen from the male to the female reproductive structures.
- Seed Dispersal - mechanisms for spreading seeds (wind, water, animals).

Microorganisms are single-celled or simple multicellular organisms that are often microscopic.
- Bacteria are single-celled organisms that can be beneficial or pathogenic.
- Viruses are non-living infectious agents that require a host to replicate.
- Fungi are decomposers that can be multicellular (mushrooms) or unicellular (yeasts).

Macromolecules are large complex molecules essential for life:
- Carbohydrates serve as an energy source (sugars, starches).
- Proteins are made of amino acids and perform various functions.
- Lipids include fats and oils, components of cell membranes, and energy storage molecules.
- Nucleic Acids (DNA and RNA) carry genetic information.

Anatomy studies the structure of the human body.
Physiology investigates the functions and processes of the body systems.
Immune System defends against infections through innate and adaptive responses.
Hormonal Regulation involves hormones controlling various body functions (e.g., metabolism, growth).