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.
Types of Cells:
- Prokaryotic: No nucleus, smaller, simpler (e.g., bacteria).
- Eukaryotic: Nucleus present, larger, complex (e.g., plant and animal cells).
Cell Organelles:
- Mitochondria: Powerhouse, energy production (ATP).
- Ribosomes: Protein synthesis.
- Endoplasmic Reticulum (ER):
  - Rough ER: Protein processing.
  - Smooth ER: Lipid synthesis.
- Golgi Apparatus: Modifies, sorts, and packages proteins.
- Nucleus: Contains genetic material (DNA).

DNA Structure: Double helix, composed of nucleotides (A, T, C, G).
Gene: Segment of DNA that codes for a protein.
Alleles: Different forms of a gene.
Mendelian Genetics: Inheritance patterns (dominant/recessive, homozygous/heterozygous).
Punnett Squares: Tool for predicting offspring genotypes.

Natural Selection: Process where organisms better adapted to their environment tend to survive and reproduce.
Evolutionary Theory: Explains the diversity of life through gradual change over time.
Fossil Record: Evidence of evolution through preserved remains of organisms.
Speciation: Formation of new species due to evolutionary processes.

Ecosystems: Interactive communities of living organisms and their physical environment.
Biomes: Large areas characterized by specific climate and vegetation (e.g., deserts, forests).
Food Chains/Webs: Models showing flow of energy and nutrients through ecosystems.
Biodiversity: Variety of life in an ecosystem; critical for resilience.

Body Systems:
- Circulatory: Transports blood, nutrients, gases.
- Respiratory: Facilitates gas exchange (O2 and CO2).
- Digestive: Breaks down food, absorbs nutrients.
- Nervous: Controls body activities through signals.
Homeostasis: Maintenance of constant internal conditions (temperature, pH).

Photosynthesis: Process by which plants convert sunlight into energy (glucose) using chlorophyll.
Plant Structures:
- Roots: Absorb water/minerals.
- Stems: Support and transport.
- Leaves: Main site of photosynthesis.

Macromolecules: Carbohydrates, proteins, lipids, nucleic acids.
- Carbohydrates: Energy source (e.g., sugars, starch).
- Proteins: Function as enzymes, structural components.
- Lipids: Fats, important for membrane structure and energy storage.
- Nucleic Acids: DNA and RNA, store and transmit genetic information.

Biotechnology: Use of living systems to develop products (e.g., genetic engineering, cloning).
Ethical Considerations: Issues surrounding genetic modification, cloning, and conservation efforts.

All living organisms have cells as their basic unit of life.
Cells arise from pre-existing cells.
Two main types of cells exist: prokaryotic and eukaryotic.
Prokaryotic cells lack a nucleus, are smaller and simpler (e.g., bacteria).
Eukaryotic cells contain a nucleus, are larger and more complex (e.g., plant and animal cells).

Mitochondria are responsible for energy production (ATP), often called the "powerhouse" of the cell.
Ribosomes are sites of protein synthesis.
The endoplasmic reticulum (ER) comes in two forms: rough and smooth.
The rough ER is studded with ribosomes and involved in protein processing.
The smooth ER lacks ribosomes and is involved in lipid synthesis.
The Golgi apparatus modifies, sorts, and packages proteins.
The nucleus houses the cell's genetic material (DNA).

DNA has a double helix structure composed of nucleotides (adenine (A), thymine (T), cytosine (C), guanine (G)).
A gene is a segment of DNA that encodes for a protein.
Alleles are different forms of a gene.
Mendelian genetics explores inheritance patterns of dominant and recessive alleles.
Punnett squares are used to predict offspring genotypes.

Natural selection favors organisms better adapted to their environment, leading to their survival and reproduction.
Evolutionary theory explains the diversification of life through gradual change over time.
The fossil record provides evidence of evolution by preserving remnants of organisms.
Speciation occurs when populations evolve into distinct species through various evolutionary processes.

Ecosystems involve interconnected communities of living organisms and their physical environment.
Biomes are vast regions characterized by specific climate and vegetation, examples include deserts and forests.
Food chains and webs model the flow of energy and nutrients through ecosystems.
Biodiversity refers to the variety of life within an ecosystem, crucial for resilience.

The human body comprises various systems with specific functions.
The circulatory system transports blood, nutrients, and gases throughout the body.
The respiratory system facilitates gas exchange, taking in oxygen (O2) and expelling carbon dioxide (CO2).
The digestive system breaks down food and absorbs nutrients.
The nervous system controls bodily functions through signals.
Homeostasis maintains constant internal conditions like temperature and pH.

Photosynthesis is the process by which plants convert sunlight into energy (glucose) using chlorophyll.
Plants are characterized by distinct structures.
Roots absorb water and minerals from the soil.
Stems provide support and transport nutrients.
Leaves are the primary sites for photosynthesis.

Macromolecules are large organic molecules essential for life.
Carbohydrates serve as an energy source, including sugars and starch.
Proteins act as enzymes and structural components.
Lipids, encompassing fats, are crucial for membrane structure and energy storage.
Nucleic acids (DNA and RNA) store and transmit genetic information.

Biotechnology leverages living systems to develop products, like genetic engineering and cloning.
Ethical considerations arise from genetic modification, cloning, and conservation efforts.